산후에 관절이 약해지는 이유! relaxin

[문형철]

Relaxin: A hormone produced during pregnancy that facilitates the birth process by causing a softening and lengthening of the cervix and the pubic symphysis (the place where the pubic bones come together). Relaxin also inhibits contractions of the uterus and may play a role in timing of delivery. Relaxin works by simultaneously cutting collagen production and increasing collagen breakdown.

A synthetic form of relaxin has been reported to be useful in treating scleroderma (a connective tissue disease that causes the skin to become tight and thick), improving the skin condition, mobility, and function.

Title	The Effect of Relaxin Treatment on Skeletal Muscle Injuries.[Article]
Source	American Journal of Sports Medicine. 33(12):1816-1824, December 2005.
Abstract	Background: Injured skeletal muscle can repair itself via spontaneous regeneration; however, the overproduction of extracellular matrix and excessive collagen deposition lead to fibrosis. Neutralization of the effect of transforming growth factor-[beta]1, a key fibrotic cytokine, on myogenic cell differentiation after muscle injury can prevent fibrosis, enhance muscle regeneration, and thereby improve the functional recovery of injured muscle. Hypothesis: The hormone relaxin, a member of the family of insulin-like growth factors, can act as an antifibrosis agent and improve the healing of injured muscle. Study Design: Controlled laboratory study. Methods: In vitro: Myoblasts (C2C12 cells) and myofibroblasts (transforming growth factor-[beta]1-transfected myoblasts) were incubated with relaxin, and cell growth and differentiation were examined. Myogenic and fibrotic protein expression‎ was determined by Western blot analysis. In vivo: Relaxin was injected intramuscularly at different time points after laceration injury. Skeletal muscle healing was eval‎uated via histologic, immunohistochemical, and physiologic tests. Results: Relaxin treatment resulted in a dose-dependent decrease in myofibroblast proliferation, down-regulated expression‎ of the fibrotic protein [alpha]-smooth muscle actin, and promoted the proliferation and differentiation of myoblasts in vitro. Relaxin therapy enhanced muscle regeneration, reduced fibrosis, and improved injured muscle strength in vivo. Conclusion: Administration of relaxin can significantly improve skeletal muscle healing. Clinical Relevance: These findings may facilitate the development of techniques to eliminate fibrosis, enhance muscle regeneration, and improve functional recovery after muscle injuries.

Musculoskeletal Aspects of Pregnancy

[Invited Review: Musculoskeletal]

Borg-Stein, Joanne MD; Dugan, Sheila A. MD; Gruber, Jane DPT, MS, OCS

From the Rehabilitation Center, Spaulding and Newton?Wellesley Hospital, Wellesley, Massachusetts.

Photos 1?3 are available for viewing in color as supplemental material on the Journal’s website at http://www.amjphysmedrehab.com/pt/re/ajpmr/aplus.htm;jsessionid=CnjUhFZ6sd72X32aFs11MbP86CqeMWCOIa8TqiBnZV5Hipakmg1h!-1778183981!-949856031!9001!-1?idx=6&cursorname=S.sh.2.14.15.17.18&fieldname=sl_100&an=00002060-200503000-00006 .

All correspondence and requests for reprints should be addressed to Joanne Borg-Stein, MD, Spaulding and Newton?Wellesley Hospital, Rehabilitation Center, 65 Walnut Street, Wellesley, MA 02481.

ABSTRACT

Borg-Stein J, Dugan S, Gruber J: Musculoskeletal aspects of pregnancy. Am J Phys Med Rehabil 2005;84:180?192.

Sex-specific care of musculoskeletal impairments is an increasingly important topic in women’s health. This is clinically relevant and of paramount importance as it pertains to diagnosis and treatment of musculoskeletal and peripheral neurologic disorders of pregnancy and the puerperium. It is estimated that virtually all women experience some degree of musculoskeletal discomfort during pregnancy, and 25% have at least temporarily disabling symptoms. This review provides information on common pregnancy-related musculoskeletal conditions, including a discussion of anatomy and physiology, diagnosis, prognosis, and treatment of these disorders.

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Sex-specific care of musculoskeletal impairments is an increasingly important topic in women’s health. It is estimated that virtually all women experience some degree of musculoskeletal discomfort during pregnancy, and 25% have at least temporarily disabling symptoms. Given the high preval‎ence of these disorders, it is imperative for physicians treating musculoskeletal disorders to be very familiar with appropriate diagnosis, prognosis, and treatment.

This article will review the current knowledge and evidence-based medical research available on this topic. There are few randomized, controlled studies in this area. Much of the available literature is based on case series and on expert opinion based on clinical practice experience. Further research is needed to establish true evidence-based practice in this area.

Goals of This Review Article

The purpose of the review is to provide a guide for appropriate differential diagnosis, eval‎uation, and management of the regional musculoskeletal and peripheral neurologic disorders that affect women during pregnancy and the postpartum period. To accomplish this, the following will be provided: (1) an overview of relevant regional musculoskeletal anatomy, (2) a discussion of hormonal and biochemical changes of pregnancy as they relate to the musculoskeletal anatomy, and (3) specific conditions and their management.

Structure of the Pelvic Walls

The pelvic walls are formed by bones and ligaments partly lined with muscles and covered with fascia. The pelvis has anterior, posterior, and lateral walls, with an inferior wall or floor (Fig. 1). The anterior pelvic wall is a shallow wall formed by the posterior surfaces of the pubic bones and symphysis pubis. This is an easily identified landmark on most women. The posterior pelvic wall is a more extensive wall that consists of the sacrum, coccyx, and piriformis muscle. The lateral pelvic wall is a component of the pelvis formed by part of the innominate bone, the obturator foramen, sacrotuberous and sacrospinous ligaments, and the obturator internus muscle and fascia. The inferior pelvic wall or pelvic floor consists of the levator ani muscles, coccygeus, and pelvic fascia and is accessible to palpation only via internal pelvic or rectal examination.

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Figure 1. Psoas and iliacus muscles. Netter illustration used with permission from Icon Learning Systems, a division of MediMedia USA, Inc. All rights reserved.

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Joints of the Pelvis

Sacroiliac joints are synovial joints. Very strong posterior and interosseous sacroiliac ligaments connect the sacrum to the ilium. These ligaments are clinically very important during pregnancy. The symphysis pubis is a cartilaginous joint between the two pubic bones. The joint is surrounded by ligaments and is subject to substantial mechanical stresses during pregnancy. The sacrococcygeal joint is a cartilaginous joint that is joined by ligaments.

Sex Differences of the Pelvis

When compared with the male pelvis, the female pelvis has distinct anatomic features that facilitate parturition. In general, the female pelvis is broader, with a rounder, ovoid shape and a roomier pelvic cavity. The ischial tuberosities are everted. The sacrum is shorter, wider, and flatter, and the anterior pubic arch is rounder and wider than that of the male anterior pubic arch.1

Nerves of the Pelvis

The lumbosacral trunk passes down into the pelvis and joins the sacral nerves as they emerge from the anterior sacral foramina. From a clinical perspective, the important nerve branches that are associated with clinical syndromes of pregnancy and childbirth include: sciatic, obturator, femoral, lateral femoral cutaneous, and pudendal.

Physiologic Changes of Pregnancy

Soft-tissue edema during pregnancy is reported by approximately 80% of women, with findings most notable during the last 8 wks of pregnancy.2 Increased fluid retention can predispose to tenosynovial or nerve entrapment (see below, “Peripheral Nerve Entrapment”).

Ligamentous laxity is another physiologic change of pregnancy. It is related to the production of the hormones relaxin and estrogen. In animal studies, relaxin is associated with remodeling from large-diameter to small-diameter collagen fibers.3 Relaxin is known to remodel pelvic connective tissue and activate the collagenolytic system.4 There may be a correlation between mean serum relaxin levels during pregnancy and symphyseal pain or low back pain. There is an initial increase of relaxin levels until a peak value at the 12th week followed by a decline until the 17th week. Thereafter, stable serum levels around 50% of the peak value were recorded.5

Weight gain during pregnancy is normal. In combination with ligamentous laxity, there may be increased joint discomfort. A 20% weight gain during pregnancy may increase the force on a joint by as much as 100%.2

Hyperlordosis of pregnancy may be seen as a gravid uterus inducing forces and accentuation of an anterior pelvic tilt. The sacroiliac joints resist this forward rotation. As the pregnancy progresses, both forward rotation and hyperlordosis increase as the sacroiliac ligaments become lax. These factors contribute to increasing mechanical strain on the low back, sacroiliac, and pelvis.2

Symphysis pubis widening begins during the 10th to 12th week of pregnancy under the influence of the hormone relaxin. This can be associated with tenderness and is usually exacerbated by exercise. Normal widening does not exceed 10 mm.6

Pubic Pain of Pregnancy

There is a spectrum of disorders affecting the pubic symphyseal region during pregnancy and parturition. Pubic symphysis regional pain occurs as a result of increased motion related to the ligamentous laxity referred to above. In a recent European study, it is estimated that the preval‎ence of this condition is 1 in 36 women.7 Mild cases of symphysis inflammation generally respond to rest and ice.

Osteitis pubis is characterized by bony resorption about the symphysis followed by spontaneous resossification.2 The pregnant or postpartum woman has a gradual onset of pubic symphysis pain, followed by rapid progression over the course of a few days to excruciating pain radiating down the inside of both thighs, exacerbated by any movement of the limbs. The prognosis for recovery is invariably good, with a self-limited course that lasts from several days to weeks before gradually subsiding.8,9 Occasionally, the course of groin/pubic pain may be quite prolonged and should be treated with initial bedrest followed by ambulation with a walker as tolerated. Anti-inflammatory agents can be given to affected women after parturition. Intrasymphyseal injection of lidocaine and steroid may shorten the duration of symptoms.10

Rupture of the symphysis pubis refers to a true rupture of the ligaments supporting the symphysis pubis and is only rarely reported. This is believed to occur as a result of the wedge effect of the forceful descent of the fetal head against the pelvic ring, usually during delivery, creating a separation of >1 cm.11 In another case series, it is suggested that symphyseal rupture can occur as a result of forceful and excessive abduction of the thighs during labor.12 Characteristically, there is a sudden pain in the region of the symphysis pubis, sometimes an audible crack, followed by radiation of pain to the back or thighs. A gap may be palpable with associated soft-tissue swelling. Treatment is generally conservative. Initial bed rest in a lateral decubitus position with a pelvic binder is indicated. Progression to weightbearing as tolerated with a walker is appropriate when symptoms permit. Complications are rare, and subsequent vaginal delivery is possible.13 In extremely rare circumstances, persistence of symptoms may warrant surgical stabilization with open reduction and internal fixation.14

Severe pelvic dislocation of pregnancy is extremely rare. Cases reported are associated with difficult parturition. Patients sustain simultaneous rupture of the symphysis pubis and sacroiliac joints, with resultant pelvic dislocation. All patients in a series from Boston developed persistent sacroiliac pain after being managed with closed reduction. The authors suggest consideration of an operative approach to patients with symphyseal diastasis of >4.0 cm.15

Low Back Pain of Pregnancy

The epidemiology of low back pain in pregnancy demonstrates incidence rates of approximately 50% among retrospective reviews.16,17 Low back pain rates have been found to increase with advancing maternal age, back pain during a previous pregnancy, and an increasing number of previous births.16 A recent study by Wang et al.18 interestingly demonstrated increased low back pain in younger women. No consistent relationship has been found with height, weight, or weight gain of the mother or weight of the baby.11 It is reported that only 32% of women with low back pain during pregnancy report this to their prenatal providers, and only 25% of prenatal care providers recommended a specific treatment. Nearly 30% of women are forced to stop performing at least one daily activity because of low back pain over the course of their pregnancy.18

Low back pain is also reported in 30?45% of women in the postpartum period.19 The main factors associated with development of postpartum back pain were previous episodes of back pain. Risk factors associated with persistent back pain after 24 mos seem to be the onset of severe pain early during gestation and the inability to reduce weight to prepregnancy level.19,20

Low back pain during pregnancy has multiple causes, and the relative frequency of these causes have not been fully established. These causes include: mechanical strain, pelvic ligamentous laxity, sacroiliac pain, vascular compression, spondylolisthesis, discogenic pain, and hip pathology (please refer to section on the hip).

One popular theory for the cause of nonspecific low back pain of pregnancy posits that the enlarging gravid uterus and accompanying compensatory lumbar lordosis contribute to substantial mechanical strain on the lower back. In addition, the tendency for pelvic rotation is increased as the lumbar lordosis increases. These altered biomechanics, in combination with relaxation of the pelvic and sacroiliac joints under the influence of relaxin, may further increase strain on the pelvis and low back.2,11,17

Lumbar disk herniations of pregnancy, although relatively uncommon, are estimated to occur in approximately 1 in 10,000 cases of lumbosacral pain of pregnancy.21 During pregnancy, noncontrast magnetic resonance imaging can be performed to identify the pathology. To date, no recognized adverse biological effects of magnetic resonance imaging on the developing fetus have been identified, although the long-term effects of magnetic resonance imaging on the developing fetus have not been fully eval‎uated.22

Another hypothesis suggests that the vascular system may play an important role in the pathogenesis of back pain during pregnancy. In a 1992 study, Fast and Hertz 23 hypothesize that prolonged time in the supine position leads to obstruction of the vena cava. They further suggest that increased pressure and venous stasis in combination with a decrease in basal oxygen saturation may lead to hypoxemia and compromise the metabolic supply of the neural structures, thus resulting in pain.

In susceptible women, pregnancy may be a factor for the development of degenerative spondylolisthesis.24 In women with previously diagnosed spondylolisthesis, no increase in low back pain or increase in slippage during pregnancy was found.25 As in other individuals with spondylolisthesis, low back pain may be unrelated to the presence of this anatomic finding and may be caused by disk, facet joint, or muscle abnormalities.

History and Physical Exam

The pregnant woman with low back pain generally reports lumbar or pelvic/sacroiliac pain aggravated by weightbearing and activity. Sitting, rest, recumbency, and use of a supportive pillow often ameliorate the symptoms. Occasionally, there is a vague accompanying posterior thigh or inguinal radiation of pain into the leg. True nerve root pain is uncommon.

The physical examination of the pregnant woman with back pain should begin with a standard neuromuscular exam that includes observation, palpation, range of motion, muscle imbalances, and a thorough neurological examination. In addition, the examiner should assess posture and degree of lordosis. Occasionally, a “step-off” sign will be appreciated in the lumbar spine and may suggest spondylolisthesis. Tenderness is often present over the sacroiliac joints and lumbar paraspinal muscles. Sacroiliac compression tests, bimanual compression over the iliac crests, and Patrick’s test all may elicit sacroiliac pain. A careful examination of the hip should be performed as well.

Treatment

The majority of patients with low back pain will respond to activity and postural modifications. Scheduled rest periods with elevation of the feet to flex the hips and decrease the lumbar lordosis help relieve muscle spasm and acute pain.11

A regular exercise program before pregnancy reduces the risk for back pain during pregnancy.26 During pregnancy, exercise may be initiated once the acute pain is controlled. Sitting pelvic tilt exercises and aquatic exercise have been shown to decrease pain intensity.27,28 Exercise to increase strength of the abdominal and back muscles is also recommended.29 Please refer to the physical therapy section later in this article for specific exercises.

Several studies suggest that use of a nonelastic maternity support binder may reduce symptoms of posterior pelvic pain.26,30 Other physical modalities of treatment may include mobilization of the sacroiliac region.31 A recent retrospective, observational study of 167 patients with low back and pelvic pain of pregnancy demonstrated improvement in 72% of patients treated with acupuncture administered during the second and third trimesters. No significant adverse effects were noted.32

The medication of choice for pain relief is acetaminophen because antiprostaglandins (aspirin and nonsteroidal anti-inflammatory drugs) are relatively contraindicated in pregnancy because they can cause premature closure of the ductus arteriosis in the fetus if given at or near term. Other medications that the United States Food and Drug Administration rates class B (no evidence of risk in humans during pregnancy) may be considered for pain control during pregnancy. These include cyclobenzaprine, oxycodone (if used for short periods not near term), and prednisone. Care should be carefully coordinated with the obstetrician.

There is no literature examining the safety or efficacy of epidural steroid injections during pregnancy. In our clinical experience, translaminar epidural steroid injections, performed without any fluoroscopic guidance, can be performed safely by an anesthesiologist or interventional pain specialist with extensive experience in epidural injections in pregnancy.

Surgery for lumbar disk herniation during pregnancy with cauda equina syndrome or progressive neurologic deficit can be safely undertaken. Brown and Levi 33 report a case series of three pregnant women who were successfully treated this way.

Peripheral Nerve Entrapment: Neuropathies of Pregnancy and the Puerperium

Peripheral nerves are susceptible to injury in the pregnant, laboring, and postpartum woman by several mechanisms, including compression, traction, ischemia, and less commonly, laceration. As would be expected biomechanically, labor and delivery are more likely to compromise the lumbosacral plexus and lower limb peripheral nerves, whereas activities of daily living and child care, especially those requiring repetitive or prolonged positioning of the upper limb, are associated with upper limb peripheral nerve injury. Upper limb neuropathies (such as median neuropathy at the wrist) can also occur during pregnancy due to peripheral edema.

Mechanisms of Peripheral Nerve Injury

Compression and traction are the most common mechanisms of peripheral nerve entrapment in pregnancy and the puerperium. Compression neuropathies are most common in anatomic locations where excessive pressure can occur (median nerve in the carpal tunnel) or in superficial nerves (common peroneal nerve at the fibular head). The endoneurium, a connective tissue matrix of collagen and fatty tissue, surrounds individual nerve fascicles, absorbing shock and dissipating pressure. Nerves with tightly packed fasciculi and thin endoneurium are more susceptible to compression. Pregnancy-related swelling and prolonged positioning increase compressive forces, resulting in increased preval‎ence of compression neuropathies in pregnancy and postpartum childcare activities.

Labor and delivery is also associated with compressive mononeuropathies and lumbosacral plexopathies.34?36 Traction neuropathies result when the stretch applied to the nerve exceeds the neural and connective tissue elastic capacity. Intrinsic nerve characteristics, such as the amount of perineurium, the lamellated sheaths of perineural cells, and collagen fibrils, have been implicated in differential risk of traction injury.37 A combination of compression and stretch may result in decreased perineural blood flow and ischemic injury. Less severe injuries that cause focal demyelination and conduction block are the most common type in pregnancy and the puerperium. These neuropathies are generally short-lived and have a good recovery.38

Carpal Tunnel Syndrome (Median Neuropathy at the Wrist)

Hand pain is the second most frequent musculoskeletal symptom of pregnancy, with carpal tunnel syndrome (CTS) frequently the cause.11 The median nerve can be entrapped at the wrist in the enclosed space formed by the carpal bones and the overlying transverse carpal ligament. CTS typically presents with pain and paresthesias in the first three digits of the hand, often bilaterally, and is most frequently diagnosed during the third trimester.39 The rate of CTS varies from 2% to 25% in pregnant women.40,41 The pain can worsen at night or during the day with repetitive wrist flexion or extension. Peripheral edema has been implicated in pregnancy-related CTS and is most common in older, primiparous women.40,42 Prolactin and fluid retention coupled with prolonged, awkward positioning of the wrist and hand may cause CTS related to nursing. The symptoms of CTS frequently resolve within days to weeks after labor and delivery;43 95% of women have resolution of symptoms within 2 wks postpartum.11 In one study, women with onset of CTS symptoms early during pregnancy had prolonged time to recovery after delivery.44

Nonsurgical management of CTS is appropriate in pregnant women because the majority of patients obtain relief after delivery. In pregnant women symptomatic enough to require treatment, splinting of the wrist in a neutral position is recommended. More than 80% of women had good relief of symptoms using thermoplastic night splints for 2 wks.40 Serial electrophysiologic studies done before and after splinting in one case study demonstrated rapid improvement in physiologic measures, mirroring clinical improvement.45 Education on correct positioning of the hand and wrist for occupational and childcare activities should be provided to women with CTS during and after pregnancy. Steroid injections are useful in patients with recalcitrant symptoms.39,43 Infrequently, surgery is indicated during pregnancy or the postpartum period for patients with ongoing severe symptomatology and positive electrodiagnostic studies.43,46

Meralgia Paresthetica (Lateral Femoral Cutaneous Neuropathy)

The lateral femoral cutaneous nerve is a pure sensory nerve supplying sensation to the anterolateral thigh. It passes slightly medial and inferior to the anterior superior iliac spine after exiting the pelvis by traveling under the inguinal ligament. Injury to the nerve causes burning, pain, or numbness in the region of innervation, known as meralgia paresthetica syndrome. Pregnancy along with obesity, diabetes mellitus, trauma, belt pressure, and anatomic variation are risk factors for meralgia paresthetica.47 A nested case-control study found that pregnant women had 12 times the likelihood of meralgia paresthetica compared with nonpregnant patients in a primary care setting.48 In patients in whom the lateral femoral cutaneous nerve bisects the inguinal ligament, the accentuated lumbar lordosis of pregnancy is thought to lead to increased risk of nerve compression.49 Lateral femoral cutaneous neuropathy was the most common finding in a prospective study of postpartum lumbosacral spine and lower limb nerve injuries resulting from labor and delivery.36 Cesarean delivery may infrequently lead to meralgia paresthetica from a wide incision, stretching, or retractor placement, although the preval‎ence does not vary substantially with method of delivery.36,50

As with CTS, pregnancy-related meralgia paresthetica syndrome typically resolves after delivery. The diagnosis is typically clinical; the nerve conduction study of the lateral femoral cutaneous nerve can be difficult to obtain, even in healthy, asymptomatic individuals. Recommendations for pregnant patients include avoidance of tight-fitting clothing along the hips or repetitive carrying of older children on the ipsilateral hip. Several authors postulate that intrapartum nerve injury can be reduced by attention to laboring practices.36,51 Consideration of frequent position changes for laboring, with avoidance of prolonged hip flexion, may reduce compression on the lateral femoral nerve. In addition, shortening pushing time by allowing the fetus to descend into the perineum without active maternal pushing may reduce nerve compression or traction.

Femoral Neuropathy and Other Intrapartum Maternal Nerve Injuries

The incidence of lumbosacral spine and lower limb nerve injuries related to labor and delivery varies in studies, depending on sample size and study methodology. A retrospective study using International Classification of Diseases, Ninth Edition, codes for nerve injury studied charts over 16 yrs for >140,000 women and found 0.08% incidence of nerve injury.52 The authors concluded that improvements in modern obstetric practice might be responsible for a reduction in nerve injury rates of almost 5% since the turn of the century.53 A more recent prospective study of >6,000 women who delivered in a 1-yr period found an almost 1% (0.92%) rate of injury.36 Injury rate was not associated with obstetric anesthesia but rather nulliparity and prolonged pushing. Many studies are limited by lack of electromyographic documentation because the injuries are frequently of limited duration and new mothers may not follow up for an electrodiagnostic study before symptom resolution. The majority of nerve injuries resolve over weeks to months.

Femoral neuropathy has been documented as a consequence of labor and delivery. During a prolonged second stage of labor, compression of the femoral nerve under the inguinal ligament may occur. Stretch or ischemia of the intrapelvic, poorly vascularized portion of the femoral nerve may be another mechanism of injury, as the femoral nerve does not descend through the true pelvis.34 However, in cases in which the iliopsoas muscle is found to be weak along with the quadriceps, the lesion may be proximal to the inguinal ligament, where branches to the iliopsoas arise.54 Femoral neuropathy can result in significant functional impairment, particularly in ascending and descending stairs, walking, and transferring from sitting to standing. Physical therapy eval‎uation and assistive-device training is mandatory before hospital discharge.

Lumbosacral Plexopathies

Lumbosacral plexopathies resulting in proximal or distal lower limb weakness can occur. Plexus-associated foot drop can result from compression of the peroneal division of the sciatic nerve in the pelvis or compression of the common peroneal nerve at the head of the fibula.49 Common peroneal nerve compression at the fibular head was documented in laboring women both from hand placement and squatting.55?58 Obturator nerve palsies have been described as related to labor and delivery. The nerve crosses the pelvic brim and may be compressed by the descending fetal head or instrumentation used for fetal evacuation.49,53

Upper Limb Pain

DeQuervain’s tenosynovitis is an inflammatory condition of the abductor pollicis longus and extensor pollicis brevis tendons of the first dorsal compartment of the wrist. It can develop in pregnancy or during the postpartum period, with localized pain along the radial aspect of the wrist. Fluid retention related to hormonal status is suspected in the pathophysiology in pregnant and lactating women. Overuse during childcare activities is also implicated.59,60 Symptoms may persist until nursing is discontinued.61

The clinical diagnosis is based on history, symptom location, and local tenderness over the first dorsal compartment. Provocative maneuvers include Finkelstein’s test, in which the pain is provoked with ulnar deviation of the wrist with the thumb flexed inside a closed fist. Symptoms are usually self-limited and respond to conservative management, including thumb spica splints, icing, and activity modification. Oral anti-inflammatory medications can be used in the postpartum patient, and corticosteroid injections to the tendon sheath are used in pregnancy and postpartum. Local corticosteroid injections were shown to be more efficacious than splinting in a study of 18 patients.62 Occasionally, operative treatment is necessary in the postpartum period.63

Lower Limb Pain: Hip Pain of Pregnancy

Hip pain in the pregnant woman can present with progressive symptoms and can lead to significant disability. There are several rare but worrisome entities that must be considered when a pregnant woman presents with complaints of hip pain. As noted earlier, there are conditions of the low back and pelvic girdle that can present with associated hip pain and should be included in the differential diagnosis. Likewise, intraarticular hip pathology can refer to the pelvis and back and can be misdiagnosed as pelvic instability. It is important to test hip range of motion, with the pelvis and lower spine maintained in a stable position, to differentiate intraarticular hip pathology from referred pain.11 In any pregnant woman presenting with antalgic gait, transient osteoporosis of the hip or osteonecrosis of the femoral head must be considered.

Transient osteoporosis of the hip is a rare condition that presents with weightbearing hip pain, usually in the third trimester of pregnancy. Plain anteroposterior radiography of the pelvis with properly positioned lead shielding may reveal osteoporosis of the femoral head and neck with preserved joint space.64,65 Magnetic resonance imaging reveals high-intensity signal in the bone marrow on T2-weighted images.66,67 Early recognition and treatment with protective weightbearing will allow the condition to be self-limited and without long-term sequelae.2 The use of antiresorptive bone agents, including calcitonin and bisphosphonates, shortened the duration of the symptoms both in pregnant and postpartum patients.68,69 However, the use of bisphosphonates during pregnancy is controversial. Several groups have found that gestational exposure to bisphosphonates was associated with decreased fetal bone growth. Bisphosphonates may have an effect on fetal serum calcium levels. If clinicians choose to start treatment before delivery, serum calcium levels should be monitored closely. There have been no reports of congenital abnormalities associated with use of bisphosphonates in animal teratology studies.70 The prognosis for natural recovery is good if the osteoporosis is associated with pregnancy and not related to preexisting osteoporosis predating the pregnancy.71 Failure to diagnose this condition can result in fracture, which can result in the need for surgical intervention.72

Avascular necrosis of the femoral head has been reported in pregnant women with no additional risk factors for avascular necrosis.73 Several theories regarding the pathogeneses have been proposed, including higher adrenocortical activity combined with weight gain and higher levels of female sex hormones in conjunction with increased interosseous pressures.74,75 The symptoms typically occur in the third trimester, with weightbearing pain in the hip, pelvis, or groin and, at times, radiating to the knee.11 Radiographic and magnetic resonance imaging can delineate the pathology, with partial femoral head involvement in most cases. Restricted weightbearing is initiated to prevent progression of femoral head necrosis, with definitive treatment after delivery as appropriate.

Other Causes of Lower Limb Pain During Pregnancy

In a case-controlled study, about 100 postpartum and matched nulliparous controls were surveyed regarding lower limb pain complaints.76 The postpartum subjects were twice as likely as the nulliparous controls to have symptoms of leg and foot pain. The majority of the postpartum women noted the onset of lower limb pain during the second or third trimester of pregnancy. History of regular exercise was not protective or causative of pain related to pregnancy.

Ligamentous laxity may be associated with lower limb injury. A case study documented transient laxity of the anterior cruciate ligament in a pregnant woman during her third trimester and postpartum period. This patient’s anterior cruciate ligament reconstruction was performed 2 mos before conception.3 Relaxin-related dissociation of large collagen fibrils was thought to be causative. The mechanism of ligamentous pain production may be secondary to strain. Ligaments, especially at the site of bony insertion, lie on a bed of well-vascularized and highly innervated insertional angle fat. There are numerous nerve endings at the attachment sites.77 The differential diagnosis in pregnant and postpartum women with musculoskeletal pain should include other bone, joint, and soft-tissue structures in addition to ligaments. For instance, the labrum of the hip or meniscus of the knee may be at greater risk of injury during pregnancy. Two cases of pregnant women presenting with acute locking of the knee were reported, including urgent arthroscopic repair of a torn meniscus.78 History of previous injury in the area, current injury in adjacent areas, or systemic metabolic conditions such as pregnancy-related osteoporosis could be associated with an acute musculoskeletal injury in pregnant women.

Sacral and tibial stress fractures, rib fractures, and vertebral fractures are documented in pregnant women related to osteoporosis.79?82 In a case study of a pregnant woman with normal lumbar and femoral bone density, bilateral sacral stress fractures were related to stress fracture due to unaccustomed loading in the last trimester.83

Recurrent ankle sprains or patellofemoral symptoms are a theoretical risk during pregnancy that women should consider in their exercise planning. Local treatment of acute lower limb musculoskeletal injury includes rest, ice, compression, and elevation. Protected mobility with orthoses or protected weightbearing with assistive devices should be employed in relation to injury with similar clinical reasoning as in the nonpregnant population. Careful observation of women who become pregnant within a few months after anterior cruciate ligament reconstruction is recommended.3

As with other medical conditions, surgery is done during pregnancy only in the setting of acute, debilitating musculoskeletal conditions. If surgery is deemed necessary, local and regional anesthetics are used due to their better safety profile because first-trimester general anesthesia is associated with a slightly increased risk of spontaneous abortion.78

Guidelines for Exercise in Pregnancy and the Postpartum Period

Girls and women are becoming more involved in and adept at exercise and competitive sports. Moderate exercise (at least 30 mins most days of the week) across the life span is the recommendation for health and well-being of all Americans.84 Women are being encouraged by their healthcare providers to exercise moderately during pregnancy unless they have any of the contraindications noted in the recommendations of the American College of Obstetrics and Gynecology (ACOG).85 The ACOG recommendations include both absolute (i.e., incompetent cervix) and relative (i.e., poorly controlled hypertension) contraindications (refer to Tables 1?3 and ACOG). The level of fitness and activity before pregnancy is the main determinant of exercise during pregnancy; however, a nonexercising woman may be open to exercise counseling during pregnancy, a time when she may be focusing on her own health.

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TABLE 1 Absolute contraindications to aerobic exercise during pregnancy

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TABLE 2 Relative contraindications to aerobic exercise during pregnancy

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TABLE 3 Warning signs to terminate exercise while pregnant

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Maternal and Fetal Effects of Exercise in Pregnancy

Numerous studies on the health risks and benefits of exercise in pregnancy to both mother and fetus have been performed. Exercise recommendations have evolved over the last several decades. Traditionally, women were instructed to reduce exercise, and nonexercisers were told not to initiate exercise when pregnant.86?88 These conservative recommendations came out of concerns for the fetus with strenuous exercise and physical labor, including disturbances in growth. Persistent elevation in maternal body temperature during the first trimester, the time of neural tube closure and organogenesis, has been linked to birth defects.87 Pregnant women should maintain moderate exercise intensity, with loose fitting clothing in ventilated areas, to help prevent persistent elevation in body temperature. Maternal concerns related to exercise include increased risk of musculoskeletal injuries.89 Later in pregnancy, the reversal of the hyperglycemic response may cause hypoglycemia in an exercising mother due to increased fetoplacental energy demands.90

More recent studies have not confirmed the increased risk to mother or fetus with moderate aerobic or strength-training exercise in women with uncomplicated pregnancy.91?94 In fact, one study showed that participation in moderate recreational activity the year before pregnancy and during early pregnancy was associated with reduced preeclampsia risk.95 Exercise may also prevent gestational diabetes and is recommended when diet alone does not provide normalization of blood sugars in pregnant women.96,97 Women involved in physical conditioning programs during pregnancy had a more favorable subjective outcome and had decreased cesarean section rates and infants with higher Apgar scores.98

Specific Exercise Guidelines During Pregnancy

The American College of Gynecology provides general guidelines for exercise during pregnancy.85 Women who were inactive before pregnancy or whose pregnancy is complicated by medical or obstetric problems are advised to seek medical advice for specific individualized exercise recommendations.85 For pregnant women previously active in recreational sports and exercise, the 2003 ACOG guidelines recommend women should continue to be active during pregnancy and “modify their usual routine as medically indicated.” For competitive athletes engaged in strenuous sports, they note that information is limited and recommend “close medical supervision.”

The 2003 Canadian clinical practice guidelines for exercise in pregnancy and the postpartum period, issued jointly by the Society of Obstetricians and Gynecologists of Canada and the Canadian Society for Exercise Physiology, provide more specific recommendation.99 Previously sedentary women should be counseled to begin with 15 mins of continuous exercise three times per week and work toward a goal of 30 mins four times per week. A case-control study of low?birth weight infants (<15th percentile for gestational age) found that the odds of having a low?birth weight infant increased by >4 fold in women exercising five times a week and greater during late pregnancy.100 The odds of low birth weight were over twice as great in mothers who exercised moderately two times a week or less. Low birth weight infants of exercising mothers are not necessarily subject to the usual risks of low birth weight.101

The Canadian guidelines also review practical issues of exercise intensity, recommending the use of the Borg Scale of Perceived Exertion, with target rating of 12?14 (somewhat hard) for exercise. Using a percentage of maximal heart rate is not appropriate during pregnancy due to a blunted heart rate response to exercise.102 The “talk test” is another proxy for maintaining moderate intensity; if the exercising mother is not able to maintain a conversation, she may be overexercising. The Canadian recommendations go beyond the ACOG guidelines in including initiation of pelvic floor exercises in the immediate postpartum period and advising mothers that moderate exercise while nursing does not negatively affect breast milk composition or infant growth.

Both the American and Canadian guidelines warn against activities with high risk of falling or abdominal trauma. They make specific mention of avoiding scuba diving and being thoughtful about acclimatization for high-altitude exercise. These guidelines also include specific warning signs to discontinue exercising, such as vaginal bleeding, preterm labor, or excessive shortness of breath (Table 3 from ACOG).

Further information on the benefits of specific exercise programs during pregnancy will likely be forthcoming given the fact that women are increasingly likely to exercise throughout their pregnancies. Pregnant women and their healthcare team should be more thoughtful about the risk of maternal inactivity for both mother and infant.

Aspects of Rehabilitation: Physical Therapeutics

Physical modalities for treatment of musculoskeletal disorders of pregnancy may be especially useful for low back and pelvic pain; however, there are special considerations for use during pregnancy. The treating physician should work closely with a physical therapist experienced in this area. A few of the commonly used modalities will be reviewed below for safety and contraindications during pregnancy.

Well-trained physical and occupational therapists with specific interest in this area can be extremely helpful in assisting the pregnant woman with management of musculoskeletal dysfunction. Therapists can provide appropriate exercise and education in body mechanics, ergonomics, posture, energy conservation, and activity modification (Table 4).

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TABLE 4 Therapy goals for musculoskeletal dysfunction of pregnancy

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Physical Agents: Considerations in Pregnancy

Treatment with physical agents may be limited by precautions or contraindications when the energy produced by the agent or the physiologic effects of the agent may reach the developing fetus. These effects may not be understood completely or agreed on. In a recent review, pregnancy is believed to be a contraindication to therapeutic ultrasound in 80% of the sources reviewed. Superficial heat is contraindicated according to 27% of the sources reviewed.103.

Heat may produce maternal hyperthermia; therefore, precaution should be considered with hot pack application to the low back and abdomen, utilizing extra toweling. Diathermy is contraindicated due to the effect of deep heat and exposure to electromagnetic fields.104 Similarly, immersion in a warm whirlpool or hot tub can produce maternal hyperthermia. Therapeutic ultrasound to produce a heating effect is also contraindicated in any area that may reach the developing fetus. Because fetal development may be affected by even subtle influences, most therapists tend to be cautious and avoid the use of therapeutic heating modalities for the pregnant woman with musculoskeletal complaints.

There are no data available in the medical literature regarding the use of cervical or lumbar traction during pregnancy. Lumbar traction belts may cause excessive pressure on the abdomen and should be avoided. Cervical traction should be used with caution due to ligamentous laxity of pregnancy.

Electrical stimulation should not be applied in areas of the low back, abdomen, or hip/pelvic girdle to avoid the potential to reach the fetus.104 Electrical current effects on the fetus are not fully understood. Interestingly, no adverse effect on the fetus was found in the most recent animal studies when electrical stimulation was performed on the S1 nerve root.105

The electrical current of transcutaneous nerve stimulation may be used safely during uncomplicated labor and delivery for pain control. In a meta-analysis of six randomized, placebo-controlled trials, transcutaneous nerve stimulation was found to provide some relief of back pain.106 Physical therapists can instruct patients in the use of transcutaneous nerve stimulation and appropriate electrode placement before delivery date.

Orthoses and Pregnancy

Physical therapists can assess the pregnant woman with back pain for the use of a lumbosacral orthosis. Limited evidence has been found to support the effectiveness of back supports in the general population.107 A pilot study eval‎uating the use of maternity back supports found a reduction in pain scores in a small population.108 Several orthoses are available for the maternity patient. Beaty et al.109 found that the Mother-To-Be orthosis (CMO, Barberton, OH), a Velcro and elastic lumbar and abdominal binder adjustable for the growing abdomen, did not adversely affect the hemodynamics of the mother or fetus.

Therapeutic Exercise

Exercise in normal-temperature pool water is advantageous to the pregnant woman. Buoyancy has the effect of unloading joints to ease painful movements. Aquatic exercises also help to control peripheral edema, common in pregnant women. The lower heart rate response with exercise in water is another reason favoring its use. Land exercise causes greater heat storage and sweat loss.110

Pelvic floor muscle training during pregnancy has been shown to prevent urinary incontinence during pregnancy and after delivery. A recent study by Morkved et al.111 demonstrated that participants in a 12-wk intensive pelvic floor muscle training program during pregnancy had significantly less urinary incontinence during pregnancy and 3 mos after delivery.

Individualized physical therapy programs have been found more effective than group sessions for the reduction of pain and sick leave due to back pain in pregnancy. The individual sessions included exercise, postural training, and ergonomics once weekly over a 5-wk period 112?114 (see supplemental material containing photos of exercises at http://www.amjphysmedrehab.com/pt/re/ajpmr/aplus.htm;jsessionid=CnjUhFZ6sd72X32aFs11MbP86CqeMWCOIa8TqiBnZV5Hipakmg1h!-1778183981!-949856031!9001!-1?idx=6&cursorname=S.sh.2.14.15.17.18&fieldname=sl_100&an=00002060-200503000-00006 ).

REFERENCES

1. Snell RS: Clinical Anatomy for Medical Students. Boston, Little Brown and Company, 1973 [Context Link]

2. Ritchie JR: Orthopedic considerations during pregnancy. Clin Obstet Gynecol 2003;46:456?66 Ovid Full Text [Context Link]

3. Blecher AM, Richmond JC: Transient laxity of an anterior cruciate ligament-reconstructed knee related to pregnancy. Arthroscopy 1998;14:77?9 [Context Link]

4. Weiss M, Nagelschmidt M, Struck H: Relaxin and collagen metabolism. Horm Metab Res 1979;11:408?10 Bibliographic Links [Context Link]

5. Kristiansson P, Svardsudd K, von Schoultz B: Serum relaxin, symphyseal pain, and back pain during pregnancy. Am J Obstet Gynecol 1996;175:1342?7 Buy Now Bibliographic Links [Context Link]

6. Young J: Relaxation of the pelvic joints in pregnancy: pelvic arthropathy of pregnancy. J Obstet Gynaecol Br Emp 1940;47:493 [Context Link]

7. Owens K, Pearson A, Mason G: Symphysis pubis dysfunction: A cause of significant obstetric morbidity. Eur J Obstet Gynecol Reprod Biol 2002;105:143?6 [Context Link]

8. Gonik B, Stringer CA: Postpartum osteitis pubis. South Med J 1985;78:213?4 Buy Now Bibliographic Links [Context Link]

9. Kubitz RL, Goodlin RC: Symptomatic separation of the pubic symphysis. South Med J 1986;79:578?80 Buy Now [Context Link]

10. Schwartz Z, Katz Z, Lancet M: Management of puerperal separation of the symphysis pubis. Int J Gynaecol Obstet 1985;23:125?8 [Context Link]

11. Heckman JD, Sassard R: Current concepts review: Musculoskeletal considerations in pregnancy. J Bone Joint Surg Am 1994;76:1720?30 [Context Link]

12. Cappiello GA, Oliver BC: Rupture of symphysis pubis caused by forceful and excessive abduction of the thighs with labor epidural anesthesia. J Fla Med Assoc 1995;82:261?3 [Context Link]

13. Culligan P, Hill S, Heit M: Rupture of the symphysis pubis during vaginal delivery followed by two subsequent uneventful pregnancies. Obstet Gynecol 2002;100(5 pt 2):1114?7 Full Text Bibliographic Links [Context Link]

14. Rommens PM: Internal fixation in postpartum symphysis pubis rupture: Report of three cases. J Orthop Trauma 1997;11:273?6 [Context Link]

15. Kharrazi FD, Rodgers WB, Kennedy JG, et al: Parturition-induced pelvic dislocation: A report of four cases. J Orthop Trauma 1997;11:277?81 Ovid Full Text [Context Link]

16. Mantle MJ, Greenwood RM, Currey HL: Backache in pregnancy. Rheumatol Rehabil 1977;16:95?101 [Context Link]

17. Carlson HL, Carlson NL, Pasternak BA, et al: Understanding and managing the back pain of pregnancy. Curr Womens Health Rep 2003;3:65?71 [Context Link]

18. Wang SM, Dezinno P, Maranets I, et al: Low back pain during pregnancy: Preval‎ence, risk factors, and outcomes. Obstet Gynecol 2004;104:65?70 Bibliographic Links [Context Link]

19. To WW, Wong MW: Factors associated with back pain symptoms in pregnancy and the persistence of pain 2 years after pregnancy. Acta Obstet Gynecol Scand 2003;82:1086?91 [Context Link]

20. To WW, Wong MW: Factors associated with back pain symptoms in pregnancy and the persistence of pain 2 years after pregnancy. Obstet Gynecol Surv 2004;59:408?9 [Context Link]

21. LaBan MM, Viola S, Williams DA, et al: Magnetic resonance imaging of the lumbar herniated disc in pregnancy. Am J Phys Med Rehabil 1995;74:59?61 [Context Link]

22. LaBan MM, Rapp NS, von Oeyen P, et al: The lumbar herniated disk of pregnancy: A report of six cases identified by magnetic resonance imaging. Arch Phys Med Rehabil 1995;76:476?9 Bibliographic Links [Context Link]

23. Fast A, Hertz G: Nocturnal low back pain in pregnancy: Polysomnographic correlates. Am J Reprod Immunol 1992;28:251?3 [Context Link]

24. Sanderson PL, Fraser RD: The influence of pregnancy on the development of degenerative spondylolisthesis. J Bone Joint Surg Br 1996;78:951?4 [Context Link]

25. Saraste H: Spondylolysis and pregnancy: A risk analysis. Acta Obstet Gynecol Scand 1986;65:727?9 Bibliographic Links [Context Link]

26. Ostgaard HC, Zetherstrom G, Roos-Hansson E, et al: Reduction of back and posterior pelvic pain in pregnancy. Spine 1994;19:894?900 Buy Now Bibliographic Links [Context Link]

27. Kihlstrand M, Stenman B, Nilsson S, et al: Water-gymnastics reduced the intensity of back pain in pregnant women. Acta Obstet Gynecol Scand 1999;78:180?5 Bibliographic Links [Context Link]

28. Suputtitada A, Wacharapreechanont T, Chaisayan P: Effect of the “sitting pelvic tilt exercise” during the third trimester in primigravidas on back pain. J Med Assoc Thai 2002;85(suppl 1):S170?9 [Context Link]

29. Spankus JD: The cause and treatment of low back pain during pregnancy. Wis Med J 1965;64:303?4 [Context Link]

30. Carr CA: Use of a maternity support binder for relief of pregnancy-related back pain. J Obstet Gynecol Neonatal Nurs 2003;32:495?502 [Context Link]

31. McIntyre IN, Broadhurst NA: Effective treatment of low back pain in pregnancy. Aust Fam Physician. 1996;25(9 suppl 2):S65?7 [Context Link]

32. Ternov NK, Grennert L, Albert A, et al: Acupuncture for lower back pain and pelvic pain in late pregnancy: A retrospective report on 167 consecutive cases. Pain Med 2001;2:204?7 [Context Link]

33. Brown MD, Levi AD: Surgery for lumbar disc herniation during pregnancy. Spine 2001;26:440?3 Ovid Full Text Bibliographic Links [Context Link]

34. Al Hakim M, Katirji MB: Femoral neuropathy induced by lithotomy position: A report of 5 cases with a review of the literature. Muscle Nerve 1993;16:891?5 [Context Link]

35. Holdcroft A, Gibberd FB, Hargrove RL, et al: Neurological complications associated with pregnancy. Br J Anaesth 1995;75:522?6 Bibliographic Links [Context Link]

36. Wong CA, Scavone BM, Dugan S, et al: Incidence of postpartum lumbosacral spine and lower extremity nerve injuries. Obstet Gynecol 2003;101:279?88 Full Text Bibliographic Links [Context Link]

37. Bonney G: Iatrogenic injuries of nerves. J Bone Joint Surg Br 1986;68:9?13 [Context Link]

38. Wilbourne AJ: Iatrogenic nerve injuries. Neurol Clin 1998;16:55?82 [Context Link]

39. Stolp-Smith KA, Pascoe MK, Ogburn PL: Carpal tunnel syndrome in pregnancy: Frequency, severity and prognosis. Arch Phys Med Rehabil 1998;79:1285?7 [Context Link]

40. Ekman-Ordeberg G, Salgeback S, Ordeberg G: Carpal tunnel syndrome in pregnancy: A prospective study. Acta Obstet Gynecol Scand 1987;66:233?5 Bibliographic Links [Context Link]

41. Voitk AJ, Mueller JC, Farlinger DE, et al: Carpal tunnel syndrome in pregnancy. Can Med Assoc J 1983;128:277?81 [Context Link]

42. Wand JS: Carpal tunnel syndrome in pregnancy and lactation. J Hand Surg Br 1990;15:93?5 [Context Link]

43. Wand JS: The natural history of carpal tunnel syndrome in lactation. J R Soc Med 1989;82:349?50 [Context Link]

44. Padua L, Aprile I, Caliandro P, et al: Carpal tunnel syndrome in pregnancy: Multiperspective follow-up of untreated cases. Neurology 2002;59:1643?6 [Context Link]

45. Weimer LH, Yin J, Lovelace RE, et al: Serial studies of carpal tunnel syndrome during and after pregnancy. Muscle Nerve 2002;25:914?7 [Context Link]

46. Assmus H, Hashemi B: Surgical treatment of carpal tunnel syndrome in pregnancy: Results from 314 cases. Nervenarzt 2000;71:470?3 [Context Link]

47. Haerer AF: DeJong’s the Neurologic Examination. Philadelphia, JB Lippincott, 1992 [Context Link]

48. van Slobbe AM, Bohnen AM, Bernsen RM, et al: Incidence rates and determinants in meralgia paresthetica in general practice. J Neurol 2004;251:294?7 Bibliographic Links [Context Link]

49. Aminoff MJ: Neurological disorders and pregnancy. Obstet Gynecol 1978;132:325?35 [Context Link]

50. Redick LF: Maternal perinatal nerve palsies. Postgrad Obstet Gynecol 1992;12:1?5 [Context Link]

51. Hansen SL, Clark SL, Foster JC: Active pushing versus passive fetal descent in the second stage of labor: A randomized controlled trial. Obstet Gynecol 2002;99:29?34 Full Text Bibliographic Links [Context Link]

52. Vargo MM, Robinson LR, Nicholas JJ, et al: Postpartum femoral neuropathy: Relic of an earlier era? Arch Phys Med Rehabil 1990;71:591?6 Bibliographic Links [Context Link]

53. Donaldson JO: Neurology of Pregnancy. Philadelphia, Saunders, 1989 [Context Link]

54. Biemond A: Femoral neuropathy, in Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology. New York, John Wiley and Sons, 1977, vol 8, pp 303?10 [Context Link]

55. Colachis SC III, Pease WS, Johnson EW: A preventable cause of foot drop during childbirth. Am J Obstet Gynecol 1994;171:270?2 Buy Now Bibliographic Links [Context Link]

56. Adornato BT, Carlini WG: “Pushing palsy”: A case of self-induced bilateral peroneal palsy during natural childbirth. Neurology 1992;42:936?7 Ovid Full Text Bibliographic Links [Context Link]

57. Reif ME: Bilateral common peroneal palsy secondary to prolonged squatting in natural childbirth. Birth 1988;15:100?2 [Context Link]

58. Babayev M, Bodack MP, Creature C: Common peroneal neuropathy secondary to squatting during childbirth. Obstet Gynecol 1998;91:830?2 Full Text Bibliographic Links [Context Link]

59. Schned ES: DeQuervain’s tenosynovitis in pregnant and postpartum women. Obstet Gynecol 1986;68:411?4 Bibliographic Links [Context Link]

60. Shumacher HR Jr, Dorwart BB, Korzeniowski OM: Occurrence of DeQuervain’s tendonitis during pregnancy. Arch Intern Med 1985;145:2083?4 [Context Link]

61. Johnson CA: Occurrence of DeQuervain’s disease in postpartum women. J Fam Pract 1991;32:325?7 [Context Link]

62. Avci S, Yilmaz C, Sayli U: Comparison of nonsurgical treatment measure for DeQuervain’s disease of pregnancy and lactation. J Hand Surg 2002;27:322?4 [Context Link]

63. Skoff HD: “Postpartum/newborn” DeQuervain’s tenosynovitis of the wrist. Am J Orthop 2001;30:428?30 [Context Link]

64. Bramlett KW, Killian JT, Nasca RJ, et al: Transient osteoporosis. Clin Orthop 1987;222:197?202 Ovid Full Text [Context Link]

65. Beaulieu JG, Razzano CD, Levine RB: Transient osteoporosis of the hip in pregnancy: Review of the literature and a case report. Clin Orthop 1976;115:165?8 Ovid Full Text [Context Link]

66. Bloem JL: Transient osteoporosis of the hip: MR imaging. Radiology 1988;167:753?5 Bibliographic Links [Context Link]

67. Takatori Y, Kokubo T, Ninomiya S, et al: Transient osteoporosis of the hip: Magnetic resonance imaging. Clin Orthop 1991;271:190?4 Ovid Full Text [Context Link]

68. Arayssi TK, Tawbi HA, Usta IM, et al: Calcitonin in the treatment of transient osteoporosis of the hip. Semin Arthritis Rheum 2003;32:388?97 Bibliographic Links [Context Link]

69. La Montagna G, Malesci D, Tirri R, et al: Successful neridronate therapy in transient osteoporosis of the hip. Clin Rheumatol 2004 Aug 19 (E-pub ahead of print) [Context Link]

70. French AE, Kaplan N, Lishner M, et al: Taking bisphosphonates during pregnancy. Can Fam Physician 2003;49:1281?2 [Context Link]

71. Phillips AJ, Ostlere SJ, Smith R: Pregnancy-associated osteoporosis: Does the skeleton recover? Osteoporos Int 2000;11:449?54 [Context Link]

72. Wood ML, Larson CM, Dahners LE: Late presentation of a displaced subcapital fracture of the hip in transient osteoporosis of pregnancy. J Orthop Trauma 2003;17:582?4 Ovid Full Text [Context Link]

73. Pellicci PM, Zolla-Pazner S, Rabhan WM, et al: Osteonecrosis of the femoral head associated with pregnancy: Report of three cases. Clin Orthop 1984;185:59?63 Ovid Full Text [Context Link]

74. Cheng N, Burssens A, Mulier JC: Pregnancy and post-pregnancy avascular necrosis of the femoral head. Arch Orthop Trauma Surg 1982;100:199?210 Bibliographic Links [Context Link]

75. Lausten GS: Osteonecrosis of the femoral head during pregnancy. Arch Orthop Trauma Surg 1991;110:214?5 Bibliographic Links [Context Link]

76. Vullo VJ, Richardson JK, Hurvitz EA: Hip, knee and foot pain during pregnancy and the postpartum period. J Fam Pract 1996;43:63?8 [Context Link]

77. Benjamin M, Redman S, Milz S, et al: Adipose tissue at entheses: The rheumatologic implications of insertional distribution. A potential site of pain and stress dissipation? Ann Rheum Dis 2004;63:1549?55 [Context Link]

78. Flik K, Anderson K, Urmey W, et al: Locked knee during pregnancy. Arthroscopy 2004;20:191?5 Bibliographic Links [Context Link]

79. Thienpont E, Simon JP, Fabry G: Sacral stress fracture during pregnancy: A case report. Acta Orthop Scand 1999;70:525?6 Bibliographic Links [Context Link]

80. Clemetson IA, Popp A, Lippuner K, et al: Postpartum osteoporosis associated with proximal tibial stress fracture. Skeletal Radiol 2004;33:96?8 Full Text [Context Link]

81. Amagada JO, Joels L, Catling S: Stress fracture of rib in pregnancy: What analgesic? J Obstet Gynaecol 2002;22:559 [Context Link]

82. Sarikaya S, Ozdolap S, Acikgoz G, et al: Pregnancy-associated osteoporosis with vertebral fractures and scoliosis. Joint Bone Spine 2004;71:84?5 [Context Link]

83. Schmid L, Pfirrmann C, Hess T, et al: Bilateral fracture of the sacrum associated with pregnancy: A case report. Osteoporos Int 1999;10:91?3 [Context Link]

84. American College of Sports Medicine: ACSM’s Guidelines for Exercise Testing and Prescription, ed 6. Philadelphia, Lippincott Williams and Wilkins, 2000 [Context Link]

85. American College of Obstetrics and Gynecology: Exercise during pregnancy and the postpartum period. Clin J Obstet Gynecol 2003;46:496?9 [Context Link]

86. American College of Obstetrics and Gynecology (ACOG): Exercise During Pregnancy and the Postnatal Period. Washington, DC, ACOG, 1985 [Context Link]

87. Shangold MM: Exercise during pregnancy: Current state of the art. Can Fam Physician 1989;35:1675?89 [Context Link]

88. Shangold MM: Pregnancy, in Haycock CE (ed): Sports Medicine for the Athletic Female. Oradell, Medical Economics Company Book Division, 1987, pp 331?8 [Context Link]

89. Clapp JF, Little KD: The interaction between regular exercise and selected aspects of women’s health. Am J Obstet Gynecol 1995;173:2?9 Buy Now Bibliographic Links [Context Link]

90. Clapp JF, Capeless EL: The changing glycemic response to exercise during pregnancy. Am J Obstet Gynecol 1991;65:1678?83 [Context Link]

91. Kardel KR, Kase T: Training in pregnant women: Effects on fetal development and birth. Am J Obstet Gynecol 1998;178:280?6 Buy Now Bibliographic Links [Context Link]

92. Clapp JF, Simonian S, Lopez B, et al: The one-year morphometric and neurodevelopmental outcome of the offspring of women who continued to exercise regularly during pregnancy. Am J Obstet Gynecol 1998;178:594?9 Buy Now Bibliographic Links [Context Link]

93. Clapp JF, Lopez B, Harcar-Sevcik R: Neonatal behavioral profile of the offspring of women who continued to exercise regularly throughout pregnancy. Am J Obstet Gynecol 1999;180:91?4 Buy Now Bibliographic Links [Context Link]

94. Sternfeld B, Queensberry CP, Eskenazi B, et al: Exercise during pregnancy and pregnancy outcome. Med Sci Sports Exerc 1995;27:634?40 Buy Now Bibliographic Links [Context Link]

95. Sorensen TK, Williams MA, Lee IM, et al: Recreational physical activity during pregnancy and risk of preeclampsia. Hypertension 2003;41:1273?80 Ovid Full Text Bibliographic Links [Context Link]

96. Dye TD, Knox KL, Artal R, et al: Physical activity, obesity, and diabetes in pregnancy. Am J Epidemiol 1997;146:961?5 Bibliographic Links [Context Link]

97. Jovanovic-Peterson L, Peterson CM: Exercise and the nutritional management of diabetes during pregnancy. Obstet Gynecol Clin North Am 1996;23:75?86 Bibliographic Links [Context Link]

98. Hall DC, Kaufmann DA: Effects of aerobics and strength conditioning on pregnancy outcomes. Am J Obstet Gynecol 1987;157:1199?203 Bibliographic Links [Context Link]

99. Davies GAL, Wolfe LA, Mottola MF, et al: Joint SOGC/CSEP clinical practice guideline: Exercise in pregnancy and the postpartum period. Can J Appl Physiol 2003;28:329?41 [Context Link]

100. Campbell MK, Mottola MF: Recreational exercise and occupational activity during pregnancy and birth weight: A case-control study. Am J Obstet Gynecol 2001;184:403?8 Buy Now Bibliographic Links [Context Link]

101. Clapp JF: Exercise and fetal health. J Dev Physiol 1991;15:9?14 Bibliographic Links [Context Link]

102. Borg GAV: Psychophysical bases of perceived exertion. Med Sci Sports Exerc 1982;14:377?81 Buy Now Bibliographic Links [Context Link]

103. Batavia M: Contraindications for superficial heat and therapeutic ultrasound: Do sources agree? Arch Phys Med Rehabil 2004;85:1006?10 [Context Link]

104. Cameron MH: Physical Agents in Rehabilitaion. St. Louis, Saunders, 2003 [Context Link]

105. Wang Y, Hassouna MM: Electrical stimulation has no adverse effect on pregnant rats and fetuses. J Urol 1999;162:1785?7 Ovid Full Text Bibliographic Links [Context Link]

106. Howell CJ: Transcutaneous nerve stimulation (TNS) in Labor, in Keirse MJNC, Renfew MJ, Neilson JP, et al (eds): Pregnancy and Childbirth Module. The Cochrane Database of Systematic Reviews, The Cochrane Collaboration, Issue 2. Oxford, Update Software, 1995 [Context Link]

107. Jellema P, van Tulder MW, van Poppel M, et al: Lumbar supports for the prevention and treatment of low back pain: A systematic review within the framework of the Cochrane Back Review Group. Spine 2001;26:377?86 Ovid Full Text Bibliographic Links [Context Link]

108. Carr CA: Use of a maternity binder for the relief of pregnancy?related back pain. J Obstet Gynecol Neonatal Nurs 2003;32:459?502 [Context Link]

109. Beaty CM, Bhaktaram VJ, Rayburn WF, et al: Low backache during pregnancy: Acute hemodynamic effects of a lumbar support. J Reprod Med 1999;44:1007?11 Bibliographic Links [Context Link]

110. McMurray RG, Katz VL, Meyer-Goodwin WE, et al: Thermoregulation of pregnant women during aerobic exercise on land and in the water. Am J Perinatol 1993;10:178?82 Bibliographic Links [Context Link]

111. Morkved S, Bo K, Schei B, et al: Pelvic floor muscle training during pregnancy to prevent urinary incontinence: A single blind randomized controlled trial. Obstet Gynecol 2003;101:313?9 Full Text Bibliographic Links [Context Link]

112. Ostgaard HC, Zetherstrom G, Ross-Hansson E, et al: Reduction of back and posterior pelvic pain in pregnancy. Spine 1994;19:894?900 Buy Now Bibliographic Links [Context Link]

113. Ostgaard HC, Zetherstrom G, Ross-Hansson E: Back pain in relation to pregnancy: A 6-year follow-up. Spine 1997;22:2945?50 Ovid Full Text [Context Link]

114. Noren L, Ostgaard S, Nielsen TF, et al: Reduction of sick leave for lumbar back and posterior pelvic pain in pregnancy. Spine 1997;22:2157?60 Ovid Full Text [Context Link]