Iliotibial band tightness and patellofemoral pain syndrome. 재미있는 논문 꼭 정리해야

[문형철]

닭이 먼저냐, 달걀이 먼저냐의 논란이겠다. 

iliotibial band tightness와 ant knee pain(PFPS) 어떤 것이 먼저 문제인가에 대한 질문은

하지만 생체역학적 관점, 치료의 관점에서 보면 ITB 문제가 해결될때만 PFPS는 치료될 수 있다. 

Iliotibial_band_tightness_and_patellofemoral_pain_syndrome.pdf

Abstract

Tight lateral structures have been implicated in subjects presenting with patellofemoral pain syndrome (PFPS). It has been

proposed that a tight iliotibial band (ITB) through its attachment of the lateral retinaculum into the patella could cause lateral patella tracking, patella tilt and compression.

Twelve subjects presenting with PFPS were compared with 12 matched control subjects. Hip adduction was measured using the Ober test in each subject as an indirect measure of ITB length. The mean values for hip adduction in the control group were 21.4 (4.9) and 20.3 (3.8) degrees in the left and right legs, respectively, and in the PFPS group, 17.3 (6.1) and 14.9 (4.2) degrees in the non-painful leg and painful leg, respectively. One way analysis of variance (ANOVA) revealed a highly significant difference between groups (F ¼ 4.485, p ¼ 0.008) and post-hoc analysis showed a significant difference between the painful leg in the PFPS group and the left and right legs in the control group, p ¼ 0.002 and 0.009, respectively.

The results from this study show that subjects presenting with PFPS do have a tighter ITB. Future work should investigate this observation prospectively in order to determine whether a tight ITB is the cause or effect of PFPS.

Patellofemoral pain syndrome (PFPS) is generally recognised as being multifactorial in origin. Many factors

associated with this condition have been described

including, abnormal lower limb biomechanics and

altered motor control and recruitment (Fredericson

et al., 2000; Earl et al., 2005). It is hypothesised that

these changes result in abnormal patellar tracking or

malalignment, with subsequent symptoms. Treatment

paradigms include mobilising tight lateral structures,

motor control and re-education of local and proximal

muscles, patella taping and biomechanical correction

with the use of orthotics (Bizzini et al., 2003; Aminaka

and Gribble, 2005).

The iliotibial band (ITB) has both a dynamic and

passive role at the patellofemoral joint. Proximally the

ITB attaches to the tensor fascia lata whilst distally,

fibres from the ITB interdigitate with vastus lateralis

(Terry et al., 1986). Most of the lateral retinaculum

(superficial oblique and deep transverse portion) arises

from the ITB (Standring, 2005), therefore the ITB indirectly

provides lateral stabilisation and acts as a passive restraint to medial patella glide. A tight ITB could

theoretically lead to lateral patella tracking, lateral

patella tilt and lateral patella compression.

Clinical assessment of ITB length remains under

debate. However, clinicians have traditionally used the

Ober test to eval‎uate hip adduction as an indirect

measure of ITB length (Puniello, 1993; Magee, 1997;

Herrington et al., 2006; Wang et al., 2006). This clinical

test has been shown to have excellent intra (ICC ¼ 0.94)

and inter-tester (ICC ¼ 0.91) reliability (Melchione and

Sullivan, 1993; Reese and Bandy, 2003).

Previous studies have attempted to quantify ITB

length as measured by the Ober test in normal subjects

(Gajdosik et al., 2003; Reese and Bandy, 2003) and those

with PFPS (Melchione and Sullivan, 1993). It has been

suggested by several authors that tightness of the ITB

could be a contributory factor for PFPS (McConnell,

1986; Gerrard, 1989; Puniello, 1993; Bizzini et al.,

2003). Whilst ITB tightness appears to be associated

with PFPS, to the authors’ knowledge, this clinical observation

remains to be tested in a case-control study.

The aim of this study was to investigate whether subjects

with PFPS had a tighter ITB measured using the

Ober test, compared to a group of subjects with no pain.

4. Discussion

The combined data for the control group provide

comparable findings to those previously reported. Reese

and Bandy (2003) reported a mean of 18.9 (7.6) hip

adduction in 61 healthy subjects compared to 20.9

(4.3) in the present study. The only study investigating

the Ober test in subjects with PFPS reported the reliability

values of the test and not the actual values for hip

adduction (Melchione and Sullivan, 1993).

Subjects presenting with PFPS in the present study had

a tighter ITB on the side with the painful knee, and this

was shown to be highly significant compared to both

knees in the control group. This data would support clinical

observations of ITB tightness in subjects presenting

with PFPS (Hudson and Darthuy, 2006). However, the

limitations of a case-control study mean that these results

do not provide evidence of causality. Additionally, the

non-painful knee in the PFPS subjects showed a trend

to be tighter than both knees in the control group. These

results could be interpreted in several ways. PFPS commonly

occurs bilaterally and if we accept the causative

model, and ITB is the cause of PFPS, perhaps the ITB

had not become sufficiently tight enough for the subjects

to develop symptoms on the contralateral side. Alternatively,

if altered biomechanics are the underlying cause

for PFPS, then proximally, poor control of medial hip rotation

via gluteus medius could place an existing tight ITB

on to a stretch, whereby it is more likely to cause lateral

tracking of the patella during dynamic weight bearing.

Results from previous studies have suggested that

strengthening muscles proximally and improving dynamic

alignment can improve the symptoms in subjects

with PFPS (Mascal et al., 2003; Cibulka and Threlkeld-

Watkins, 2005). Distally, excessive or uncontrolled pronation

would also increase lower extremity internal rotation,

which would have a similar effect on the ITB length.

This may explain why orthoses may have a role to play in

some subjects with PFPS (Gross and Foxworth, 2003).

Treatment paradigms for PFPS have included mobilising

tight lateral structures, and bracing and taping to provide

a sustained stretch on these structures. The latter has

been shown to provide short-term pain reduction in these

subjects (Herrington, 2004). Some studies have shown

short-term deformation of the ITB with stretching. This

has been shown directly using ultrasonography (Wang

et al., 2006) and indirectly using kinematic and kinetic

analysis (Fredericson et al., 2002). However, to date there

is no study that has investigated the long-term effects of

ITB stretching and mobilisation on ITB length. Whether

a tight ITB is causative or a result of PFPS, it is useful to

have a valid measure of ITB length.

There are some study limitations that should be

acknowledged. The test procedure for this study was

adopted from Reese and Bandy (2003) who reported

good reliability for the Ober test. However, for pragmatic

reasons, no tester reliability was conducted in

this study. The tester attempted to control for hip rotation

during the Ober test as most clinicians would in the

usual patient setting. Whilst this is difficult to standardise,

it should reasonably consistent for the same tester.

Alternatively, markers could have been placed on the

patella and distal femur in an attempt to more accurately

control this variable. A customised questionnaire

was used to eval‎uate the type and frequency of physical

activity and sport. Whilst this was not validated, it was

used to ensure there was no specific physical activity that

dominated either group and could have potentially been

a confounding factor.

[이주운]

예 공감하는 바입니다~ 하지만 장경인대의 tightness가 있더라도 무릎 통증이 없는 경우도 많은걸로 알고 있습니다.
또한 tightness가 있으나 약증을 동반하는 경우가 많더라구요~^^ 좋은 자료 잘보고 갑니다^^ㅂ