immobilization에 의한 문제 해결을 위한 의학적 스트레칭과 연부조직 이완의 원리- 대박자료

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아주아주 오랫동안 찾고 싶었던 자료, 정리하고 싶었던 내용

medical stretching

immobilization

panic bird...

The term mobility can be described based on two different but interrelated parameters. It is often defined as the ability

of structures or segments of the body to move or be moved to allow the presence of range of motion for functional activities (functional ROM).1,134 It can also be defined as the ability of an individual to initiate, control, or sustain

active movements of the body to perform simple to complex motor skills (functional mobility).38,118,134 

- mobility의 정의는 두가지 서로다른 것에 기초함. 하지만 그들은 서로 연관됨. 그것은 때로 인체의 분절 또는 구조가 이동하는 것을 정의하기도 하고, 기능적 관절가동범위를 위한 움직임의 허용을 말하기도 함. mobility는 또한 개인이 인체를 단순한 움직임에서 복잡한 움직임을 시작하고, 조절하고, 지속하는 능력을 말하기도 함. 

Mobility, as it relates to functional ROM, is associated with joint integrity as well as the flexibility (i.e., extensibility of soft tissues that cross or surround joints—muscles, tendons, fascia, joint capsules, ligaments, nerves, blood vessels, skin), which are necessary for unrestricted, pain-free movements of the body during functional tasks of daily living.

- mobility는 기능적 rom과 연관되어 관절 완전성 뿐 아니라 유연성과 연관됨. 

- 유연성(연부조직의 신장성, 관절을 가로지르거나 관절 주위를 둘러싼 근육, 인대, 섬유막, 관절낭, 인대, 신경, 혈관, 피부)

- 이는 일상활동에서 제한되지 않아야 하고, pain free 움직임을 해야함. 

The ROM needed for the performance of functional activities does not necessarily mean full or “normal” ROM. Sufficient mobility of soft tissues and ROM of joints must be supported by a requisite level of muscle strength and endurance and neuromuscular control to allow the body to accommodate to imposed stresses placed upon it during functional movement and thus to enable an individual to be functionally mobile. 

- 기능적 활동을 위한 rom은 full 또는 정상 rom을 필요로 하지 않음. 

- 연부조직의 충분한 움직임과 관절 rom은 충분한 근력과 지구력, 신경근육 조절이 완성되어 인체가 기능적 활동을 하는 동안 노출되는 부하에 적응할 수 있을 만큼이어야 함. 

Furthermore, soft tissue mobility, neuromuscular control, and muscular endurance and strength consistent with demand are thought to be an important factor in the prevention of injury or re-injury of the musculoskeletal system.69,74,75,80,159

- 게다가, 연부조직 가동성, 신경근육조절, 근 지구력, 근력은 근골격계 손상방지를 위한 중요한 요소임. 

Hypomobility (restricted motion) caused by adaptive shortening of soft tissues can occur as the result of many disorders or situations. Factors include (1) prolonged immobilization of a body segment, (2) sedentary lifestyle, (3) postural malalignment and muscle imbalances, (4) impaired muscle performance (weakness) associated with an array of musculoskeletal or neuromuscular disorders, (5) tissue trauma resulting in inflammation and pain, and (6) congenital or acquired deformities. 

- 연부조직의 적응성 짧아짐에 의해 발생하는 저운동성(움직임 제한)은 많은 질환의 결과에 의해서 발생할 수 있음.

- 1) 몸 분절의 지속적인 고정, 2) 앉아서 활동하는 삶, 3) 자세부정렬과 근육불균형, 4) 근골격계 또는 신경근 질환과 연관된 근력약화, 5) 염증과 통증을 유발하는 조직 타박상, 6) 선천적 또는 후천적 기형 등의 요소에 의함. 

Any factor that limits mobility, that is, causes decreased extensibility of soft tissues, may also impair muscular  performance.60,85 Hypomobility, in turn, can lead to functional limitations and disability in a person’s life.8,18

- 움직임 제한 요소는 연부조직 신장성 감소에 의함. 이는 근육 기능 제한을 야기함. 저운동성은 기능적 제한을 야기함. 

Just as strength and endurance exercises are essential interventions to improve impaired muscle performance or prevent injury, when restricted mobility adversely affects function and increases the risk of injury, stretching interventions become an integral component of the individualized rehabilitation program. 

- 근력과 근지구력 운동은 손상을 방지하거나 기능부전 근육기능 개선을 위한 필수적 요소. 제한된 움직임이 역으로 기능에 영향을 미치고, 손상 위험을 증가시시킬때...  스트레칭은 개별화된 재활프로그램의 필수 요소...

Stretching exercises are also thought to be an important element of fitness and conditioning programs designed to promote wellness and reduce the risk of injury and reinjury. Stretching is a general term used to describe any therapeutic maneuver designed to increase the extensibility of soft tissues, thereby improving flexibility by elongating (lengthening) structures that have adaptively shortened and have become hypo mobile over time.7,71,154

- 스트레칭 운동은 건강요소에 중요한 한가지이고, conditioning programs...

- 스트레칭은 연부조직의 신장성을 증가시키는 중요한 치료법, 그래서 적응성으로 짧아지거나 시간이 지나면서 저운동성을 가진 조직을 늘림으로서 유연성 증가키는 방법..

Only through a systematic examination, eval‎uation, and diagnosis of a patient’s presenting problems can a therapist determine what structures are restricting motion and if, when, and what types of stretching procedures are indicated.

- 시스템적 검사, 측정, 진단은 치료사가 움직임 제한을 가진 조직을 파악하고.. 어떤 종류의 스트레칭이 적응증인지를 가림...

Early in the rehabilitation process manual stretching and joint mobilization, which involve direct, “hands-on”

intervention by a practitioner, may be the most appropriate techniques. Later, self-stretching exercises performed independently by a patient after careful instruction and close supervision may be a more suitable intervention. In some situations the use of mechanical stretching devices are indicated, particularly when manual therapies have been ineffective.

- 재활 과정에서 스트레칭과 관절가동기법은 초기에 치료사의 손을 이용한 도수치료를 이용하는것이 가장 적합한 테크닉임. 

- 이후에 자가 스트레칭은 주의깊은 교육이후에 환자스스로 시행함. 

- 어떤 상황에서 기계적 스트레칭도구는 적응증이 됨. 특히 도수치료가 비효과적일때...

Regardless of the types of stretching procedures selected for an exercise program, if the gain in ROM is to become permanent it must be complemented by an appropriate level of strength and endurance and used on a regular basis in functional activities.

- 운동치료 프로그램을 위한 스트레칭 종류에 상관없이 .. 만약 rom이 완전하다면... 최적 수준의 근력, 근지구력에 의해서 보완되어야 함. 

The stretching interventions described in this chapter are designed to elongate the contractile and non-contractile components of muscle-tendon units and periarticular structures. The efficacy of these interventions is explored throughout the chapter. In addition to the stretching procedures for the extremities illustrated in this chapter, self-stretching exercises for each region of the body are described and illustrated in Chapters 16 through 22. Joint mobilization and manipulation procedures of extremity joints are described and illustrated in Chapter 5.

- 수축구조와 비수축구조의 늘림...  앞으로 소개...

DEFINITIONS OF TERMS RELATED TO MOBILITY AND STRETCHING

Flexibility 유연성

Flexibility is the ability to move a single joint or series of joints smoothly and easily through an unrestricted, pain-free ROM.85,105 Muscle length in conjunction with joint integrity and the extensibility of periarticular soft tissues determine flexibility.1 Flexibility is related to the extensibility of musculotendinous units that cross a joint, based on their ability to relax or deform and yield to a stretch force. 

- 유연성은 단일 관절 또는 연속된 관절이 부드럽게 움직이는 능력이고 ... 제한되지 않은 통증없는 rom이 되는 상태

- 관절 완전성과 관절 주위연부조직의 신장성과 연관된 근육 길이는 유연성으로 정의됨.

- 유연성은 스트레치 힘에 기초하고, 변형 또는 이완 능력에 기초하여 관절을 가로지르는 근건 단위의 신장성과 연곤됨. 

The arthrokinematics of the moving joint (the ability of the joint surfaces to roll and slide) as well as the ability of periarticular connective tissues to deform also affect joint ROM and an individual’s overall flexibility.

- 관절운동형상학(관절면을 roll and slide하는 능력) 뿐만 아니라 결합조직의 변형능력은 개인의 전체적인 유연성과 관절 rom에 영향을 줌. 

Dynamic and Passive Flexibility 능동적 수동적 유연성

Dynamic flexibility. 능동적 유연성

This form of flexibility, also referred to as active mobility or active ROM, is the degree to which an active muscle contraction moves a body segment through the available ROM of a joint. It is dependent on the degree to which a joint can be moved by a muscle contraction and the amount of tissue resistance met during the active movement.

- 능동적 유연성은 능동적 가동성 또는 능동적 rom이라고 언급됨. 이는 능동적 근육 수축이 관절의 가능한 rom을 통해 몸을 움직이는 정도를 말함. 

- 능동적 유연성은 어떤 관절이 근수축에 의해 움직일 수 있는 정도와 움직임 동안 만나는 조직적항의 정도에 의존함. 

Passive flexibility. 수동적 유연성

This aspect of flexibility, also referred to as passive mobility or passive ROM, is the degree to which a joint can be passively moved through the available ROM and is dependent on the extensibility of muscles and connective tissues that cross and surround a joint. Passive flexibility is a prerequisite for but does not ensure dynamic flexibility.

- 수동적 유연성은 수동적 움직임 또는 수동적 rom이라고 언급됨. 이는 어떤 관절이 수동적으로 가능한 rom범위로 움직이는 정도를 말함. 그리고 관절을 가로지르는 근육과 결합조직의 신장성에 의존함. 

- 수동적 유연성은 필수요소이지만 동적 유연성을 보장하지는 못함. 

Hypomobility 저운동성

Hypomobility refers to decreased mobility or restricted motion. A wide range of pathological processes can restrict movement and impair mobility. There are many factors that may contribute to hypomobility and stiffness of soft tissues, the potential loss of ROM, and the development of contractures. These factors are summarized in Table 4.1.

- 저운동성은 제한된 움직임이나 감소된 움직임을 말함. 

- 많은 병리적 과정이 움직임을 제한하고 기능부전을 유발함. 

- 아래표 참고!!

지속적 immobilization

1) 외부요인 - 골절, 수술, 연부조직 타박 상

    casts and splint

    skeletal traction

2) 내부요인 

   통증  - microtrauma or macrotrauma, 퇴행성 관절

   관절염증 부종 - 관절질환 또는 타박상

   근육, 건, 섬유막 질환  - 근염, 건염, 섬유막염

   피부질환 - 화상, skin grafts, scleroderma(공피증)

   뼈질환 - 골극, 강직, 수술적 fusion

   혈관질환 - 말초신경의 부종

3) 좌식생활과 습관적 부전 또는 불균형 자세

4) 마비, 근육 tone장애, 근육 불균형 - 신경근 질환

5) postural malalignment - 측만증, kyphosis 

스트레칭의 적응증

# 관절움직임 범위는 연부조직이 유착, 구축, 반흔조직이 발생하여 그들의 신장성을 잃어 제한이 발생하는 것임. 결국 기능적 움직임 제한을 야기함.

# 제한된 움직임은 구조적 변형을 야기할 수 있음. 

# 근위약과 반대조직의 짧아짐.

# 근골격계 손상 예방을 위한 전체적인 fitness 프로그램의 일부

# 격렬한 운동 전후에 운동후 근육통을 최소화하기 위해 시행

Contracture(다른 글에서 정리된 글 클릭!!) 

Designation of Contractures by Location

Contracture Versus Contraction

Types of Contracture

Myostatic Contracture

Pseudomyostatic Contracture

Arthrogenic and Periarticular Contractures

Fibrotic Contracture and Irreversible Contracture

Selective Stretching 선택적 스트레칭

Selective stretching is a process whereby the overall function of a patient may be improved by applying stretching techniques selectively to some muscles and joints but allowing limitation of motion to develop in other muscles or joints. When determining which muscles to stretch and which to allow to become slightly shortened, the therapist must always keep in mind the functional needs of the patient and the importance of maintaining a balance between mobility and stability for maximum functional performance.

- 선택적 스트레칭은 환자의 전체적 기능이 적용된 스트레칭 테크닉에 의해서 증진되는 과정으로 어떤 근육과 관절이 움직임 제한을 허용하게 하는 것. 어떤 근육 스트레칭이 결정될때, 어떤 것은 약간 짧아짐을 허용하므로 치료사는 항상 환자의 기능적 요구를 기억해야 하고, 최대기능 수행을 위한 가동성과 안정성 사이의 균형을 유지하는 것이 중요함. 

The decision to allow restrictions to develop in selected musculotendon units and joints is usually made in patients with permanent paralysis. For example: In a patient with spinal cord injury, stability of the trunk is necessary for independence in sitting. With thoracic and cervical lesions, the patient does not have active control of the back extensors. If the hamstrings are routinely stretched to improve or maintain their extensibility and moderate hypomobility is allowed to develop in the extensors of the low back, this enables a patient to lean into the slightly shortened structures and have some trunk stability for long-term sitting. However, the patient must still have enough flexibility for independence in dressing and transfers. Too much limitation of motion in

the low back can decrease function.

Allowing slight hypomobility to develop in the long flexors of the fingers while maintaining flexibility of the wrist enables the patient with spinal cord injury who lacks innervation of the intrinsic finger muscles to develop grasp ability through a tenodesis action. 

Overstretching and Hypermobility(과스트레칭과 과운동성)

Overstretching is a stretch well beyond the normal length of muscle and ROM of a joint and the surrounding soft tissues,85 resulting in hypermobility (excessive mobility). Creating selective hypermobility by over-stretching may be necessary for certain healthy individuals with normal strength and stability participating in sports that require extensive flexibility.

- 과도한 스트레칭은 근육의 정상길이를 넘어서는 것 뿐만 아니라 관절의 rom 그리고 주위연부조직의 정상길이를 넘어서게 하여 관절의 과운동성을 유발함. 과도한 스트레칭에 의한 선택적 과운동성의 창조는 특정스포츠에서 필요할 수 있음. 

Overstretching becomes detrimental and creates joint instability when the supporting structures of a joint and the strength of the muscles around a joint are insufficient and cannot hold a joint in a stable, functional position during activities. Instability of a joint often causes pain and may predispose a person to musculoskeletal injury.

- 과도한 스트레칭은 해롭고, 관절의 구조와 근육길이가 불충분할때 관절불안정성을 만들어 일상활동에서 기능적 손실을 초래함. 관절의 불안정성은 통증을 야기하고 근골격계 손상의 예측인자임. 

PROPERTIES OF SOFT TISSUE— RESPONSE TO IMMOBILIZATION AND STRETCH

연부조직의 고정과 스트레치에 반응하는 특성

The ability of the body to move freely, that is, without restrictions and with control during functional activities, is dependent on the passive mobility of soft tissues as well as active neuromuscular control. Motion is necessary for the health of tissues in the body.111 As mentioned previously, the soft tissues that can become restricted and impair mobility are muscles with their contractile and non contractile elements and various types of connective tissue (tendons, ligaments, joint capsules, fascia, skin). 

- 아무런 제한없이 그리고 기능적 활동을 하는 동안 잘 조절되어 몸이 자유롭게 움직이기 위한 능력은 연부조직의 수동적 움직임(passive mobility) 뿐 아니라 능동적인 신경근 조절에 달려있음. 

- 동작은 인체에서 조직의 건강을 위해 필수조건임. 

-  앞에서 언급했듯이 연부조직은 제한되고 움직임 손상(impairment mobility)이 될수 있는데, 이는 수축구조인 근육과 비수축구조인 요소인 다양한 형태의 결합조직인 건, 인대, 관절낭, 섬유막, 피부)때문임. 

For the most part, decreased extensibility of connective tissue, not the contractile elements of muscle tissue, is the primary cause of restricted ROM in both healthy individuals and patients with impaired mobility as the result of injury, disease, or surgery.

- 대부분  제한된 ROM의 첫번째 원인은 근육조직의 수축구조가 아닌 결합조직의 감소된 신장성이 제한된 것임.  이는 건강한 사람이나 손상, 질병 또는 수술의 결과로 손상된 움직임과 연관되어 있음.

Morphological adaptations of tissues often accompany immobilization. Each type of soft tissue has unique properties that affect its response to immobilization and its ability to regain extensibility after immobilization. When stretching procedures are applied to these soft tissues, the direction, velocity, intensity (magnitude), duration, and frequency of the stretch force as well as tissue temperature affect the responses of the various types of soft tissue.

- 연부조직의 형태학적 적응은 때로 immobilization을 동반함. 각각의 연부조직은 독특한 특성을 가지는데, immobilization에 반응하고, immobilization후에 신장성을 다시 얻는 능력을 가짐. 

- 연부조직에 스트레칭이 적용될때, "방향, 속도, 강도 시간, 스트레칭 힘의 주기, 온도 등은 연부조직의 다양한 형태에 영향을 미침.

Mechanical characteristics of contractile and non contractile soft tissue and the neurophysiological properties of contractile tissue affect tissue lengthening. Most of the information on the biomechanical, biochemical, and neurophysiological responses of soft tissues to immobilization and remobilization is derived from animal studies; and as such, the exact physiological mechanism by which stretching procedures produce an increase in the extensibility of human tissues is still unclear. 

- 수축구조와 비수축구조의 기계적 특성과 수축구조인 근육의 신경생리학적 특성은 연부조직 늘어남에 영향을 미침. 

- 이러한 연부조직에 대한 생체역학, 생체화학, 신경생리학적 반응은 동물연구로부터 나왔고, 정확한 생리학적 기전은 밝혀지지 않았음. 

Despite this, an understanding of the properties of these tissues and their responses to immobilization and stretch is the basis for selecting and applying the safest, most effective stretching procedures in a therapeutic exercise program for patients with impaired mobility.

- 이러한 고정과 스트레칭에 대한 반응의 한계가 있음에도 불구하고, 안전하고 좀더 효과적인 스트레칭은 움직임 손상의 환자 운동프로그램에 중요한 역할을 함. 

When soft tissue is stretched, elastic, viscoelastic, or plastic changes occur. 

- 연부조직이 스트레치될때, 탄성, 점탄성, 가소성 변화가 일어남.

1. Elasticity is the ability of soft tissue to return to its prestretch resting length directly after a short-duration stretch force has been removed.36,92,94,130 

- 탄성은 연부조직인 짧은 스트레칭 힘의 적용이후에 스트레치 전단계의 길이로 되돌아가는 능력

2. Viscoelasticity is a time-dependent property of soft tissue that initially resists deformation, such as a change in length, of the tissue when a stretch force is first applied. If a stretch force is sustained, viscoelasticity allows a change in the length of the tissue and then enables the tissue to return gradually to its prestretch state after the stretch force has been removed.

- 점탄성은 연부조직의 시간의존성 특성으로 스트레치 힘이 적용될 때 초기에는 길이변화와 같은 변형에 저항함. 

- 만약 스트레치 힘이 지속되면, 점탄성은 조직의 길이 변화를 허용함. 그리고 나서 연부조직이 스트레치 전단계로 점차적으로 되돌아오는 능력

3. Plasticity is the tendency of soft tissue to assume a new and greater length after the stretch force has been removed. Both contractile and non contractile tissues have elastic and plastic qualities; however, only connective tissues, not the contractile elements of muscle, have viscoelastic properties.

- 가소성은 스트레치 힘이 가해진 후에 연부조직이 새롭고 길어진 길이를 유지하는 능력

- 수축구조와 비수축구조는 탄성과 가소성능력을 가짐. 하지만 수축구조인 근육이 아니라 오직 결합조직이 점탄성 능력을 가짐 

- 다시 설명) 결합조직은 탄성, 가소성을 가질 뿐아니라 점탄성능력을 가짐. 나머지 구조는 탄성과 가소성을 가짐. 

Mechanical Properties of Contractile Tissue

Muscle is composed of both contractile and non contractile connective tissues. The contractile elements of muscle

(Fig. 4.1) give it the characteristics of contractility and irritability. The noncontractile connective tissue in and around

muscle (Fig. 4.2) has the same properties as all connective tissue, including the ability to resist deforming forces.92,102,103 

- 근육은 수축과 비수축 결합조직으로 구성됨. 

- 수축구조인 근육(근절)은 수축성과 흥분성의 특성을 가짐.

- 비수축구조인 결합조직인 근외막, 근주막, 근내막은 변형힘에 저항하는 점탄성이라는 결합조직의 특성을 가짐. 

The connective tissue structures, which act as a “harness” of a muscle, are the endomysium, which is the innermost layer that separates individual muscle fibers and myofibrils; the perimysium, which encases fiber burrelles; and the epimysium, which is the enveloping fascial sheath around the entire muscle. It is the connective tissue framework of muscle that is  the primary source of a muscle’s resistance to passive elongation.33,92,113 When contractures develop, adhesions in and between collagen fibers resist and restrict movement.33

- 결합조직구조는 근육의 조정벨트와 같은 역할을 하는데, 근내막은 각각의 근섬유와 근원섬유를 분리하는 역할을 함. 

- 근주막은 fiber burrelles를 둘러쌈. 근외막은 전체근육을 둘러싸는 fascial sheath가 있음. 

- 근육의 결합조직 골격(framework)은 근육의 수동적 늘어남에 저항하는 1차 원인임. 

- 구축이 발생할 때, 콜라겐 섬유사이와 내부의 유착은 움직임에 저항하고 제한함. 

Contractile Elements of Muscle

Individual muscles are composed of many muscle fibers that lie in parallel with one another. A single muscle fiber is made up of many myofibrils. Each myofibril is composed of even smaller structures called sarcomeres, which lie in series within a myofibril. The sarcomere is the contractile unit of the myofibril and is composed of overlapping myofilaments of actin and myosin that form cross-bridges.

- 각각 근육은 많은 근섬유로 구성. 

- 단일 근섬유는 많은 근원섬유로 이루어짐. 

- 각각의 근원섬유는 근절로 구성됨. 근절은 근원섬유의 수축구조인 액틴과 마이오신이 교차다리연결 형태를 취함. 

참고) 근육 수축의 최소단위는 근섬유(muscle fiber) 

근섬유는 근내막이 바깥에서 둘러싸고, 내측에는 절연체(insulator)가 있어 motor end plate로 연접한 단위임. 

하나의 근섬유에는 수천개의 근원섬유가 있음. 근절-근절-근절 = 근원섬유(myofibrils)임. 

The sarcomere gives a muscle its ability to contract and relax. When a motor unit stimulates a muscle to contract, the actin-myosin filaments slide together, and the muscle actively shortens. When a muscle relaxes, the cross-bridges slide apart slightly, and the muscle returns to its resting length (Fig. 4.3).

- 근절은 근육의 수축과 이완능력을 제공함. 운동단위가 근육수축을 자극할때, 액틴-마이오신 필라멘트는 서로 미끄러지면서 수축함. 근육이 이완될때, 교차연결이 떨어지면서 근육의 안정길(resting length)이로 되돌아감. 

Mechanical Response of the Contractile Unit to Stretch and Immobilization 

There are a number of changes that occur over time in the anatomical structure and physiological function of the contractile units (sarcomeres) in muscle if a muscle is stretched during an exercise or if it is immobilized in either a lengthened or shortened position for an extended period of time and then remobilized. A discussion of these changes follows. Of course, the non contractile structures in and around muscle also affect a muscle’s response to stretch and  immobilization. Those responses and adaptations are discussed later in the chapter.

- 근육의 수축구조인 근절을 변화시키는 많은 해부학적, 생리학적 기능이 있음. 운동을 하는 동안 근육이 스트레치 되거나 짧아진 상태, 늘어난 상태로 고정이 오래 지속된 후에 다시 움직이는 등...

- 근육을 둘러싼 근막(비수축구조) 또한 스트레치와 고정에 영향을 받고 있음. 이 문제에 대해서는 다음 챕터에서 다시 논의함. 

Response to Stretch

When a muscle is stretched and elongates, the stretch force is transmitted to the muscle fibers via connective tissue (endomysium and perimysium) in and around the fibers. It is hypothesized that molecular interactions link these noncontractile elements to the contractile unit of muscle, the sarcomere.36

- 근육이 스트레치되고 늘어날때, 스트레치 힘은 결합조직(근내막과 근주막)을 통해 근섬유로 전달됨. 

- 이러한 비수축구조에서 수축구조인 근육, 근절로 이어지는 분자생물학적 연관성이 가설로 제기됨.

During passive stretch both longitudinal and lateral force transduction occurs.36 When initial lengthening occurs in the series elastic (connective tissue) component, tension rises sharply. After a point, there is mechanical disruption (influenced by neural and biochemical changes) of the cross-bridges as the filaments slide apart, leading to abrupt lengthening of the sarcomeres, sometimes referred to as sarcomere give.52 

- 수동적 스트레치 동안 종축과 외측힘의 변환이 일어남. 초기에 결합조직 탄성구조가 연속적으로 길이 늘어남이 발생할때, 장력은 급격하게 증가함. 이 지점이후에 액틴-마이오신 교차연결다리의 기계적 파열이 발생하여 근절의 갑작스러운 늘어남이 야기됨. 때때로 근절 포기(Sarcomere give)라고 일컬어짐. 

When the stretch force is released, the individual sarcomeres return to their resting length36,94 (see Fig. 4.3). As noted previously, the tendency of muscle to return to its resting length after short-term stretch is called elasticity.92,130 If more permanent (plastic) length increases are to occur, the stretch force must be maintained over an extended period of

time.36

- 스트레치 힘이 이완될때, 각각의 근절은 근육의 안정길이로 되돌아감. 짧은 시간 스트레치 이후에 근육의 안정길이로 되돌아가는 것을 "탄성"이라고 함. 만약 좀더 지속적인 길이 늘어남(가소성 늘어남)이 발생하려면, 스트레치 힘은 일정시간을 넘어서 유지되어야 함. 

Response to Immobilization and Remobilization

1. Morphological changes. 

If a muscle is immobilized for a prolonged period of time, the muscle is not used during functional activities, and consequently the physical stresses placed on the muscle are substantially dimished. 

This results in 

1) decay of contractile protein in the immobilized muscle, 

2) a decrease in muscle fiber diameter, 

3) a decrease in the number of myofibrils, and 

4) a decrease in intramuscular capillary density, 

5) the outcome of which is muscle atrophy and weakness (decreased muscle force). 

6) As the immobilized muscle atrophies, an increase in fibrous and fatty tissue in muscle also occurs.111

- 만약 근육이 오랜기간동안 고정되면, 근육은 기능적 활동을 하는동안 사용하지 못하고, 이어서 생리적 스트레스에 놓여지면서 근육은 감소됨

- 그 결과 

1) 수축구조 단백질(액틴과 마이오신) 붕괴를 야기하고, 

2) 근섬유 직경이 감소되고, 

3) 근원섬유 숫자가 줄어들고, 

4) 근육내 혈관 밀도가 낮아지고, 

5) 결국 근위축과 근위약으로 진행함. 

6) 근육고정에 의한 근위축은 근육내에 섬유화와 지방조직이 증가하는 결과를 초래함. 

The composition of muscle affects its response to immobilization, with atrophy occurring more quickly and more extensively in tonic (slow-twitch) postural muscle fibers than in phasic (fast-twitch) fibers.94 The duration and position of immobilization also affect the extent of atrophy and loss of strength and power. The longer the duration of immobilization, the greater is the atrophy of muscle and loss  of functional strength. Atrophy can begin within as little as a few days to a week.83,84,141 

- 고정은 근육의 조성에 영향을 미치고, 근위축이 빠르게 진행하는데, 빠른 연축 섬유보다 느린 연축섬유가 좀더 심하게 진행함. 

- 고정의 기간과 위치는  근육위축의 범위에 영향을 미치고 근력을 감소시킴. 

- 긴기간동안의 고정은 근육 위축과 근력의 감소를 초래함. 근위축은 며칠에서 1주일이내에 시작될 수 있음. 

Not only is there a decrease in the cross-sectional size of muscle fibers over time, an even more significant deterioration in motor unit recruitment occurs as reflected by electromyographic activity.94 Both compromise the force-producing capabilities of the muscle.

- 고정의 시간이 길어지면 근섬유의 단면적 사이즈가 줄어들 뿐 아니라 운동단위 동원능력도 심각하게 손상됨. 

2. Immobilization in a shortened position. 

When a muscle is immobilized in a shortened position for several weeks, which is often necessary after a fracture or surgical repair of a muscle tear or tendon rupture, there is a reduction in the length of the muscle and its fibers and in the number of sarcomeres in series within myofibrils as the result of sarcomere absorption. 56,81,135,138,155 

- 근육이 몇주동안 짧아진 상태에서 고정이 지속되면, 근육 길이의 감소, 근섬유의 근절숫자 감소가 발생하는데, 이는 근절 흡수의 결과로 근원섬유내에서 발생함. 

81번 논문.

The effect of limb immobilization on muscle function and protein composition.

Jokl P, Konstadt S.

Abstract

The treatment of skeletal injuries often requires immobilization for extended periods. Immobilization causes muscle disuse atrophy, which extends the duration of incapacitation following the healing of the skeletal injury. To eval‎uate the role of immobilization position on the skeletal muscle, an experimental study using an animal model was undertaken. Cats were divided into four groups, with one hind limb immobilized in a plaster spica cast such that the gastrocnemius and soleus muscles were held in either a stretched, shortened, or neutral position. After four weeks of immobilization, functional and quantitative assays of muscle tissue were obtained and correlated. 

- 고양이의 근육을 4주 고정후 관찰

The shortened muscles weighed less, had a lower total content and concentration of myofibrillar proteins (the contractile protein of muscle tissue), and generated less maximum tetanic tension than either the muscles held in neutral or stretched length position. Decreased maximum tetanic tension resulted from the preferential loss of contractile protein. The remaining myofibrillar protein in the shortened muscle showed contractile dysfunction. The ability to maintain initial twitch strength (an endurance function) for five minutes varied with position but was not statistically significant in this study. 

- 짧아진 근육은 무게가 줄어들었는데, 근원섬유 단백질(액틴-마이오신 필라멘트)의 농도와 구조가 낮아짐. 

- 남아있는 짧아진 근원섬유 단백질은 수축 기능장애를 보임. 

- 또한 초기 twitch strength(연축근력)을 유지하는 지구력 기능이 떨어짐. 

The data suggest that muscle maintained in a shortened position atrophies more rapidly, with greater loss in contractile function and myofibrillar and sarcoplasmic proteins than the stretched and neutrally positioned muscles.

- 이 연구는 짧아진 상태에서 근육위축이 유지될대, 근위축이 좀더 빠르게 진행하고 수축기능이 좀더 많이 떨어진다는 것을 밝힘. 그리고 근원섬유와 sarcoplasmic 단백질감소가 늘어나거나 중립위치 근육보다 더 빨리 진행한다는 것을 알아냄. 

This absorption occurs at a faster rate than the muscle’s ability to regenerate sarcomeres in an attempt to restore itself. The decrease in the overall length of the muscle fibers and their in series sarcomeres, in turn, contributes to muscle atrophy and weakness. It has also been suggested that a muscle immobilized in a shortened position atrophies and weakens at a faster rate than if it is held in a lengthened position over time.17

- 근육을 짧아진 상태에서 장기고정 후에 근원섬유의 흡수 비율은 회복을 하려는 비율보다 흡수하려는 속도가 더 빠름. 

- 근섬유의 길이 감소와 근절감소는 근위축과 근위약을 야기함. 

- 짦아진 자세로 근육을 고정했을때, 근위축과 근위약은 길어진 상태로 고정했을때보다 다 빠른 속도로 일어남.

There is a shift to the left in the length–tension curve of a shortened muscle, which decreases the muscle’s capacity to produce maximum tension at its normal resting length as it contracts.60 The increased proportion of fibrous tissue and subcutaneous fat in muscle that occurs with immobilization contributes to the decreased extensibility of the shortened muscle but may also serve to protect the weakened muscle when it stretches.33,61 

- 짧아진 근육의 길이-장력커브는 좌측으로 이동하고, 이는 근육의 최대장력 생성을 감소시킴. 

- 고정과 함께 진행하는 섬유조직과 근육내 지방증가는 짧아진 근육의 신장성 감소에 공헌하지만 근육을 스트레칭할때 약해진 근육을 보호함. 

3. Immobilization in a lengthened position. 

Sometimes a muscle is immobilized in a position of maximum available length for a prolonged period of time. This occurs with the application of a series of positional casts (serial casts)76 or the use of a dynamic splint to stretch a long-standing  contracture and increase ROM.10,68,106 There is some evidence from animal studies135,138,155 to suggest that if a muscle is held in a lengthened position for an extended time period, it adapts by increasing the number of sarcomeres in series (myofibrillogenesis36) to maintain the greatest functional overlap of actin and myosin filaments. 

- 가끔 근육이 최대로 길어진 상태로 고정됨. 

- 근절의 숫자가 증가하여 myofibrillogenesis가 일어나는 현상이 발생. 

This may lead to a relatively permanent (plastic) form of muscle lengthening if the newly gained length is used on a regular basis in functional activities.

- 근원섬유 재생(myofibrillogenesis)는 늘어난 근육길이의 영원한 늘어남 형태를 야기할 수 있음. 만약 새로 얻어진 늘어난 길이가 기능적 활동에서 정상적으로 사용된다면...

The minimum time frame necessary for a stretched muscle (fiber) to become a longer muscle (fiber) by adding

sarcomeres in series is not known. In animal studies that have reported increased muscle length as the result of myofibrillogenesis, the stretched muscle was continuously immobilized in a lengthened position for several weeks.135,138,155 

- 근원섬유재생이 유지되기 위한 최소한 시간에 대한 연구는 동물 연구에서 "근육이 늘어난 상태로 몇주"지속해야..

There is speculation that this same process contributes to gains in ROM associated with use of serial casts76 and dynamic splints68,106 and possibly as the result of stretching exercises.36

The adaptation of the contractile units of muscle (an increase or decrease in the number of sarcomeres) to prolonged

positioning in either lengthened or shortened positions is transient, lasting only 3 to 5 weeks if the muscle resumes its preimmobilization use and degree of lengthening for functional activities.84,135 In clinical situations, this underscores the need for patients to use full-range motions during a variety of functional activities to maintain the full available ROM.

- 수축구조인 근육이 오랜 기간 짧아지거나 길어진 자세로 유지되는 적응은 영원한 것이 아닌 일시적인 현상임. 3-5주를 고정한 후 근육이 다시 움직이면 기능적 활동을 위한 근육길이의 정도와 사용가능함. 임상적 상황에서  이러한 이해는 중요함. ...

스트레칭시 신경생리적 요소(특히 근방추에 의한)

Neurophysiological Properties of Contractile Tissue

The neurophysiological properites of the muscle-tendon unit also influence a muscle’s response to stretch and the effectiveness of stretching interventions to elongate muscle. In particular, two sensory organs of muscle-tendon units, the muscle spindle and the Golgi tendon organ, are mechanoreceptors that convey information to the central nervous system about what is occurring in a muscle-tendon unit and affect a muscle’s response to stretch.

- 근육-건 단위의 신경생리적 요소는 스트레칭에 대한 근육의 반응에 영향을 미치고, 스트레칭 치료의 효과로 근육길이를 늘림. 

- 특히 근방추와 골지건기관은 근육-건 단위에서 일어나는 정보를 중추신경계에 전달하는 기계적 수용기이고, 스트레칭에 반응하여 근육에 영향을 미침. 

Muscle Spindle

The muscle spindle is the major sensory organ of muscle and is senstive to quick and sustained (tonic) stretch (Fig. 4.4). The main function of muscle spindles is to receive and convey information about changes in the length of a

muscle and the velocity of the length changes.

- 근방추는 지속적인 스트레칭과 빠른 스트레칭에 반응하는 근육의 주요감각기관임. 근방추의 주요기능은 근육의 길이변화와 길이변화의 속도에 대하여 정보를 주고받는 역할을 함. 

1. 추외근 섬유(extrafusal fiber) : 알파운동신경원-운동신경-운동종판의 운동단위(motor unit)의 지배를 받아 움직이는 근육

2. 추내근 섬유(intrafusal fiber) : 감마운동신경원-afferent nerve, efferent nerve-muscle spine로 연결되어 감각(근육의 길이변화와 길이변화 속도)를 전달하고, 감마운동신경원의 지배를 받아 근육을 움직임. 

3. 근방추(muscle spindle) 

1)  fluid로 가득찬 공간안에 nuclear bag1, 2 fiber와 nuclear chain fiber가 있어 primary stretch receptor와 secondary stretch receptor에서 감지되는 근육길이변화와 속도변화를 구심전달함. 이는 group 2 afferent nerve와 group 1a afferent nerve가 담당. 

2) nuclear bag fiber와 nuclear chain fiber에 감마원심신경에 의한 neuromuscular junction이 있어 근방추의 미세근수축 조절을 가능하게 함. 

• dynamic nuclear bag fibers (bag₁ fibers)
• static nuclear bag fibers (bag₂ fibers)
• nuclear chain fibers and the axons of sensory neurons.

Muscle spindles are small, encapsulated receptors composed of afferent sensory fiber endings, efferent motor

fiber endings, and specialized muscle fibers called intrafusal fibers. Intrafusal muscle fibers are bundled together and lie between and parallel to extrafusal muscle fibers that make up the main body of a skeletal muscle.61,77,98,120

- 근방추는 작고, 캡슐로 둘러싸인 감각을 구심전달하는 수용기와 움직임을 담당하는 원심 운동섬유 수용기가 있음. 이를 추내근섬유라고 함. 

- 추내근 섬유는 추외근 섬유와 병렬로 배열되어 있음. 

Because intrafusal muscle fibers connect at their ends to extrafusal muscle fibers, when a muscle is stretched, intrafusal fibers are also stretched. Only the ends (polar regions), not the central portion (equatorial region), of an intrafusal fiber is contractile. Consequently, when an intrafusal muscle fiber is stimulated and contracts, it lengthens the central portion. Small-diameter motor neurons, known as gamma motor neurons, innervate the contractile polar regions of intrafusal muscle fibers and adjust the sensitivity of muscle spindles. Large-diameter alpha motor neurons innervate extrafusal fibers. 

- 추내근 섬유는 한쪽끝에 추외근 섬유와 연결되어 있기 때문에, 근육이 늘어날때 추내근 섬유는 함께 이완됨.

- 근방추의 끝(polar regions)은 수축구조임. 중앙은 비수축구조

- 추내근 섬유가 감마운동신경의 자극을 받아 수축할때, 비수축구조인 central portion은 당겨짐. 

- 작은 직경의 운동신경(감마운동신경원으로 불림)은 근방추 수축구조인 polar region에 신경지배하여 추내근 섬유를 수축하게 하고, 근방추의 민감성을 조정함. 

- 큰 직경의 알파운동신경원은 추외근 섬유에 신경지배함. 

There are two general types of intrafusal fiber: nuclear bag fibers and nuclear chain fibers, so named because of the arrangement of their nuclei in the central portions of the fibers. Primary (type Ia fiber) afferent endings, which arise from nuclear bag fibers, sense and cause muscle to respond to both quick and sustained (tonic) stretch. 

- 근방추에는 두가지 추내근 섬유가 있음. nuclear bag fiber, nuclear chain fiber

- 1a afferent 섬유는 nuclear bag fiber로 이어져 지속적인 장력의 늘어남과 빠른 움직임에 반응하여 정보를 주고 받음. 

• dynamic nuclear bag fibers (bag₁ fibers)
• static nuclear bag fibers (bag₂ fibers)
• nuclear chain fibers and the axons of sensory neurons.

However, secondary (type II) afferents from the nuclear chain fibers are sensitive only to tonic stretch. Primary and secondary fibers synapse on the alpha or gamma motoneurons, which when stimulated cause excitation of their own extrafusal and intrafusal fibers, respectively. There are essentially two ways to stimulate these sensory fibers by means of stretch; one is by overall lengthening of the muscle, and the other is by stimulating contraction of intrafusal fibers via the gamma efferent neural pathways.

- 2 구심섬유는 nuclear chain fiber로 연결되어 오직 tonic stretch에만 반응함. 

- 참고로 nuclear chain fiber는 골지건기관과 연결되어 장력변화와 연관됨. 

- 1차, 2차 섬유가 알파 또는 감마운동신경원에 시냅스함. 그래서 추외근 섬유와 추내근 섬유의 흥분을 야기하는 자극을 함. 

- 이 감각신경을 자극하는 두가지 스트레치 방법이 있음. 하나는 근육을 전체적으로 늘리는 것이고, 다른 하나는 감마 원심신경섬유를 경유하여 추내근 섬유를 수축하는 방법임. 

Golgi Tendon Organ

The Golgi tendon organ (GTO) is a sensory organ located near the musculotendinous junctions of extrafusal muscle fibers. The function of a GTO is to monitor changes in tension of muscle-tendon units. These encapsulated nerve endings are woven among collagen strands of a tendon and transmit sensory information via Ib fibers. These sensory organs are sensitive to even slight changes of tension on a muscle-tendon unit as the result of passive stretch of a muscle or with active muscle contractions during normal movement.

- 골지건기관은 추외근 섬유의 근건접합부 근처에 위치하는 감각기관. 

- 골지건기관의 기능은 근육-건 단위의 장력 변화를 모니터하는 것임. 

- 이들 캡슐로 둘러싸인 신경말단은 힘줄의 콜라겐 가닥으로 직물처럼 짜여져 있고, 1b섬유를 통해 장력변화 정보를 전달함. 

- 이러한 감각기관은 근-건단위에서 발생하는 약간의 장력변화에도 민감하여 근육의 수동적 스트레치동안의 장력변화 또는 정상적인 움직임 동안 근육의 능동적 수축동안의 장력변화를 감지함. 

When tension develops in a muscle, the GTO fires, inhibits alpha motoneuron activity, and decreases tension in the muscle-tendon unit being stretched.61,77,120 With respect to the neuromuscular system, inhibition is a state of decreased neuronal activity and altered synaptic potential, which reflexively diminishes the capacity of a muscle to contract.74,77,98 

- 근육에서 장력이 발생하면, 골지건기관은 발화하여 알파운동신경 활성을 억제함. 그리고 근-건 단위에서 스트레치되는 장력을 감소시킴. 

- 신경근육 시스템에 의존하여, 억제는 감소된 신경활성의 상태이고, 변형된 synaptic potential 상태임. 이는 반사적으로 근수축능력을 감소시킴. 

Originally, the GTO was thought to fire and inhibit muscle activation only in the presence of high levels of muscle tension as a protective mechanism. However, the GTO has since been shown to have a low threshold for firing (fires easily) so it can continuously monitor and adjust the force of active muscle contractions during movement or the tension in muscle during passive stretch.53,120

- 원래 골기건기관은 인체보호기전으로 높은 근육장력이 있을때, 발화 그리고 억제하는 것으로 생각되어 왔음. 

- 하지만 골지건기관은 낮은 역치에서도 쉽게 발화되기 때문에, 움직임 동안의 능동적 근수축과 근육의 수동적 스트레치동안 장력을  지속적으로 모니터하고 조정하는 역할을 함. 

Neurophysiological Response of Muscle to Stretch

When a stretch force is applied to a muscle-tendon unit either quickly or over a prolonged period of time, the primary and secondary afferents of intrafusal muscle fibers sense the length changes and activate extrafusal muscle fibers via alpha motor neurons in the spinal cord, thus activating the stretch reflex and increasing (facilitating) tension in the muscle being stretched. The increased tension causes resistance to lengthening and, in turn, is thought to compromise the effectiveness of the stretching procedure.

- 스트레치 힘이 근육-건 단위에 빠르게 또는 지속적으로 오랜기간 적용될 때, 추내근 섬유의 primary and secondary 구심섬유는 길이 변화를 감지하여  척수의 알파운동신경원을 경유하여 추외근 섬유를 활성화하여 '스트레치 반사형태의 근수축"을 일으켜 늘어난 근육에 장력을 증가시킴.  

- 늘어난 장력은 근육길이가 더이상 길어지는 것을 막고, 스트레칭 과정의 효과를 상쇄시키는 것으로 생각됨. 

When the stretch reflex is activated in a muscle being lengthened, decreased activity (inhibition) in the muscle on the opposite side of the joint, referred to as reciprocal inhibition, may also occur.98,147 However, this phenomenon has been documented only in studies using animal models. 

- 늘어난 근육에서 스트레치 반사가 활성화되면 상호억제라고 불리는 반대쪽 근육의 활성감소가 일어남. 하지만 이러한 현상은 동물모델에서 연된 것임. 

To minimize activation of the stretch reflex and the subsequent increase in muscle tension and reflexive resistance to

muscle lengthening during stretching procedures, a slowly applied, low-intensity, prolonged stretch is considered preferable to a quickly applied, short-duration stretch.

- 스트레치 과정동안 근육 길이늘어남에 반사적인 저항과 연속적인 근육긴장의 증가, 스트레치 반사의 활성을 최소화하기 위해서는 천천히 힘을 적용하고, 낮은 강도, 지속적인 스트레칭이 고려됨. 짧은 시간 스트레치로 빠르게 적용하는 것보다는...

In contrast, the GTO, as it monitors tension in the muscle fibers being stretched, has an inhibitory impact on the level of muscle tension in the muscle-tendon unit in which it lies, particularly if the stretch force is prolonged. 

- 반대로  스트레치 힘이 오랫동안 지속되면, 근육 스트레치되는 동안 근섬유 장력을 모니터하는 기관인 골지건기관은 근육-건 단위에서 근육긴장의 정도를 억제하는 기능을 함. 

This effect is called autogenic inhibition.61,92,98,120 Inhibition of the contractile components of muscle by the GTO contributes to reflexive muscle relaxation during a stretching maneuver, enabling a muscle to be elongated against less muscle tension. It is thought that if a low-intensity, slow stretch force is applied to muscle, the stretch reflex is less likely to be activated as the GTO fires and inhibits tension in the muscle, allowing the parallel elastic component (the sarcomeres) of the muscle to remain relaxed and to lengthen.

- 이 현상은 자발적 억제(autognic inhibition)라고 부름. 

- 스트레칭을 시행하는 동안 골지건기관의 반사에 의한 수축구조인 근육의 억제는 반사적 근육이완을 일으켜 근육을 늘어나게 함. 

- 낮은 강도, 천천히 가해지는 스트레치 힘이 근육에 적용되면 스트레치 반사는 골지건기관 발화와 근육에서 장력이 억제되어 덜 일어나 근절이 늘어나도록 함. 

참고) Autogenic inhibition reflex is a sudden relaxation of muscle upon development of high tension. It is a self-induced, inhibitory, negative feedback lengthening reaction that protects against muscle tear. Golgi tendon organs are receptors for the reflex. Autogenic inhibition (historically known as the inverse myotatic reflex or autogenetic inhibition) refers to a reduction in excitability of a contracting or stretched muscle, that in the past has been solely attributed to the increased inhibitory input arising from Golgi tendon organs (GTOs) within the same muscle. The reduced efferent (motor) drive to the muscle by way of autogenic inhibition is a factor believed to assist target muscle elongation.^[1]

- 자발적 억제 반사는 근육에 높은 장력이 제공될때 갑작스러운 이완이 일어나는 것을 말함. 이것은 스스로 일어나고, 억제적이고 negative feedback 늘어남 반응으로 근육파열을 보호함. 

- 골지건기관은 반사를 위한 수용기임. 자발적 억제는 전통적으로 myotatic reflex라고 불렸고, 근육이 늘어나거나 수축의 흥분성을 억제하는 것임. 

That being said, improvement in muscle extensibility attributed to stretching procedures are more likely due to tensile stresses placed on the noncontractile connective tissue in and around muscle than to inhibition of the contractile elements of muscle.102,103,140 A discussion of the effects of stretching on noncontractile soft tissue follows.

Mechanical Properties of Noncontractile Soft Tissue

비수축 연부조직의 기계적 특성

Noncontractile soft tissue permeates the entire body and is organized into various types of connective tissue to support

the structures of the body. Ligaments, tendons, joint capsules, fasciae, noncontractile tissue in muscles (see Fig. 4.2), and skin have connective tissue characteristics that can lead to the development of adhesions and contractors and thus affect the flexibility of the tissues crossing joints. 

- 비수축 연부조직은 우리몸 전체에 걸쳐있고, 인체구조를 지지하는 다양한 형태의 결합조직으로 구조화되어 있음. 

- 인대, 건, 관절낭, 섬유막, 근육의 근막과 피부는 결합조직특성을 가지고 유착과 구축을 일으킬 수 있으면서 관절조직의 유연성에 영향을 미침. 

When these tissues restrict ROM and require stretching, it is important to understand how they respond to the intensity and duration of stretch forces and to recognize that the only way to increase the extensibility of connective tissue is to remodel its basic architecture.33 

- 이러한 조직이 rom제한을 일으킬때 스트레칭이 필요함. 이때 스트레칭의 강도와 시간에 따라 어떻게 반응하는가를 이해하는 것은 중요함. 

Composition of Connective Tissue

Connective tissue is composed of three types of fiber: collagen, elastin and reticulin, and non fibrous ground substance. 30,66,144 

- 결합조직은 콜라겐, 엘라스틴, 레티큘린 그리고 비섬유성 세포기질로 구성됨. 

1. Collagen fibers. 

Collagen fibers are responsible for the strength and stiffness of tissue and resist tensile deformation. Tropocollagen crystals form the building blocks of collagen microfibrils. Each additional level of composition of the fibers is arranged in an organized relationship and dimension (Fig. 4.5). 

- 콜라겐 섬유는 조직의 강도와 강직도를 책임지고, 장력변화에 저항함. 

- 트로포콜라겐 크리스탈...

There are six classes with 19 types of collagen; the fibers of tendons and ligaments mostly contain type I collagen, which is highly resistant to tension. 144 As collagen fibers develop and mature, they bind together, initially with unstable hydrogen bonding, which then converts to stable covalent bonding. The stronger the bonds, the greater is the mechanical stability of the tissue. Tissue with a greater proportion of collagen provides greater stability. 

- 19가지 형태의 콜라겐을 가진 6가지 분류가 있음. 

- 힘줄과 인대는 대개 type 1 콜라겐 섬유로 구성되어 있고, 장력에 높은 저항을 보임. 

- 콜라겐 섬유가 발달 성숙함에 따라 그들은 서로 강하게 붙고, 초기에는 불안정한 수소결합(hydorgen bonding)임. 차츰 성숙 발달함에 따라 안정적인 공유결합(covalent bonding)으로 변화함. 

- 강한 공유결합으로 변화한 인대, 힘줄은 조직의 기계적 안정성이 커짐. 콜라겐 비율이 많으면 많을수록 강한 안정성을 제공함. 

2. Elastin fibers. 

Elastin fibers provide extensibility. They show a great deal of elongation with small loads and fail abruptly without deformation at higher loads. Tissues with greater amounts of elastin have greater flexibility. 

- 엘라스틴 섬유는 신장성을 제공함. 엘라스틴 섬유는 높은 부하에 변형없이 늘어남. 

- 인체조직에 엘라스틴 섬유가 많으면 좀더 많은 유연성을 가짐.

3. Reticulin fibers. 

Reticulin fibers provide tissue with bulk. 

- 레티큘린 섬유는 조직에 용적을 제공함. 

4. Ground substance. 

Ground substance is made up of proteoglycans (PGs) and glycoproteins. The PGs function to hydrate the matrix, stabilize the collagen networks, and resist compressive forces. (This is most important in cartilage and intervertebral discs.) The type and amount of PGs are proportional to the types of compressive and tensile stress the tissue undergoes.60 The glycoproteins provide linkage between the matrix components and between the cells and matrix opponents. 

- 기질은 프로테오글리칸과 글리코프로틴으로 구성됨. 

- 프로테오글라칸은 기질을 수화시키는 기능을 가지며, 콜라겐 네트워크 안정성을 제공하고, 압박부하에 저항하게 함. 

- 이 기능은 관절 연골과 추간판에서 중요한 역할을 수행함. 

- 프로테오글리칸의 형태와 양은 압박과 장력부하에 비례함. 

- 글리코프로틴은 세포와 기질 사이에 연결을 제공함. 

참고) 복합탄수화물(complex carbohydrade)은 2가지 형태

1) glycoproteins  

- 단백질이 많고, 포도당이 적음

- immunoglobulin(IG), cell membrane receptor 형태로 존재함. 

Glycoproteins are proteins that contain oligosaccharide chains (glycans) covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also glycosylated. Glycoproteins are often important integral membrane proteins, where they play a role in cell–cell interactions. Glycoproteins are also formed in the cytosol, but their functions and the pathways producing these modifications in this compartment are less well understood.^[2]

2) proteoglycan

- 포도당이 많고, 단백질이 적음. 

- glycosaminoglycan형태이고, extracellular matrix의 주요 구성물

Proteoglycans are proteins^[1] that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan (GAG) chain(s).^[2] The point of attachment is a Ser residue to which the glycosaminoglycan is joined through a tetrasaccharide bridge (e.g. chondroitin sulfate-GlcA-Gal-Gal-Xyl-PROTEIN). The Ser residue is generally in the sequence -Ser-Gly-X-Gly- (where X can be any amino acid residue, but Proline), although not every protein with this sequence has an attached glycosaminoglycan. The chains are long, linear carbohydrate polymers that are negatively charged under physiological conditions, due to the occurrence of sulfate and uronic acid groups. Proteoglycans occur in the connective tissue.

Function[edit]

Proteoglycans are a major component of the animal extracellular matrix, the "filler" substance existing between cells in an organism. Here they form large complexes, both to other proteoglycans, to hyaluronan and to fibrous matrix proteins (such as collagen). They are also involved in binding cations (such as sodium, potassium and calcium) andwater, and also regulating the movement of molecules through the matrix. Evidence also shows they can affect the activity and stability of proteins and signalling molecules within the matrix. Individual functions of proteoglycans can be attributed to either the protein core or the attached GAG chain and serve as lubricants.

Synthesis[edit]

The protein component of proteoglycans is synthesized by ribosomes and translocated into the lumen of the rough endoplasmic reticulum. Glycosylation of the proteoglycan occurs in the Golgi apparatus in multiple enzymatic steps. First a special link tetrasaccharide is attached to a serine side chain on the core protein to serve as a primer for polysaccharide growth. Then sugars are added one at a time by glycosyl transferase. The completed proteoglycan is then exported in secretory vesicles to the extracellular matrix of the tissue.

Proteoglycans and disease[edit]

An inability to break down proteoglycans is characteristic of a group of genetic disorders, calledmucopolysaccharidoses. The inactivity of specific lysosomal enzymes that normally degrade glycosaminoglycans leads to the accumulation of proteoglycans within cells. This leads to a variety of disease symptoms, depending upon the type of proteoglycan that is not degraded.

In essence, the ground substance is mostly an organic gel containing water that reduces friction between fibers, transports nutrients and metabolites, and may help prevent excessive cross-linking between fibers by maintaining space between fibers.41,144 

- 본질적으로 기질은 organic gel로 물을 많이 함유하여 섬유사이의 마찰을 줄이고, 영양물과 대사물질은 전달함. 

- 그리고 기질은 섬유사이의 공간유지에 의해 섬유가 교차연결을 하는데 과도한 교차연결을 막을 수 있음. 

Mechanical Behavior of Noncontractile Tissue

비수축 조직의 기계적 특성

The mechanical behavior of the various non contractile tissues is determined by the proportion of collagen and elastin fibers and by the structural orientation of the fibers. The proportion of proteoglycans (PGs) also influences the mechanical properties of connective tissue. Those high in collagen and low in PGs are designed to resist high tensile loads; those tissues that withstand greater compressive loads have greater concentrations of PGs.60

- 비수축성 조직의 역학적 행위는 콜라겐과 엘라스틴 섬유의 비율과 섬유의 구조 방향에 의해서 결정됨. 

- 프로테오글리칸의 비율은 결합조직의 기계적 특성에 영향을 줌. 

- 콜라겐비율이 높고, 프로테오글라칸이 적음은 높은 장력부하에 저항하도록 디자인됨.  

- 높은 압박부하를 견디는 조직은 프로테오글리칸의 농도가 높음. 

Collagen is the structural element that absorbs most of the tensile stress. Collagen fibers elongate quickly under light loads (wavy fibers align and straighten). With  increased loads, tension in the fibers increases, and the fibers stiffen. The fibers strongly resist the tensile force, but with continued loading the bonds between collagen fibers begin to break. When a  substantial number of bonds are broken, the fibers fail. When tensile forces are applied the maximum elongation of collagen is less than 10%, whereas elastin may lengthen 150% and return to its original configuration. Collagen is five times as strong as elastin. The alignment of collagen fibers in various tissues reflects the tensile forces acting on that tissue (see Fig. 4.5).

- 콜라겐은 대부분의 장력부하를 흡수하는 구조임. 콜라겐 섬유는 가벼운 부하에서는 빠르게 늘어남. 

- 부하가 증가함에 따라, 섬유에 걸리는 장력은 증가하고 콜라겐 섬유는 단단해짐. 

- 콜라겐 섬유는 장력부하에 강하게 저항하지만 지속적인 부하와 함께 콜라겐 섬유사이의 연결이 깨지기 시작함. 

- 결합의 실제적인 숫자가 깨지면 섬유는 제기능을 잃어버림. 장력이 콜라겐의 늘어남에 최대로 작용할때, 10%이하로 늘어남. 반면에 엘라스틴 섬유는 150%까지 늘어날 수 있음. 

- 콜라겐은 엘라스틴 섬유보다 5배가 강함. 다양한 조직에서 콜라겐 섬유의 배열은 장력힘을 반영함. 

In tendons, collagen fibers are parallel and can resist the greatest tensile load. They transmit forces to the bone created by the muscle. In skin, collagen fibers are random and weakest in resisting tension. In ligaments, joint capsules, and fasciae, the collagen fibers vary between the two extremes, and they resist multidirectional forces. Ligaments that resist major joint stresses have a more parallel orientation of collagen fibers and a larger cross-sectional area.116

- 힘줄에서 콜라겐 섬유는 가장 강한 장력부하를 견딜 수 있도록 평행구조임. 힘줄은 근육에 의해서 생성된 힘을 뼈에  전달함. 

- 피부에서 콜라겐 섬유는 자유롭게 배열되어 장력에 가장 취약함. 

- 인대, 관절낭, 섬유막에서 콜라겐 섬유는 양극단 사이로 다양하게 배열되어 다양한 힘에 저항함. 

- 관절에 가해지는 부하에 저항하는 인대는 콜라겐 섬유가 좀더 평행구조..

Interpreting Mechanical Behavior of Connective Tissue: The Stress–Strain Curve

장력-응력 커브

The stress–strain curve illustrates the mechanical strength of structures (Fig. 4.6) and is used to interpret what is happening to connective tissue under stress loads.30,93,142,144,166 

- 장력-응력커브는 구조의 기계적 강도를 보여줌. 

Stress and Strain

Stress is force per unit area. Mechanical stress is the internal reaction or resistance to an external load. There are

three kinds of stress.

- 스트레스는 단위 면적에 주어지는 힘. 기계적 스트레스는 내적인 반응 또는 외부힘에 대한 저항임. 3종류의 스트레스가 있음. 

1. Tension: a force applied perpendicular to the cross-sectional area of the tissue in a direction away from the tissue. A stretching force is a tension stress.

- 장력은 스트레칭과 같이 당기는 힘

2. Compression: a force applied perpendicular to the cross-sectional area of the tissue in a direction toward the tissue. Muscle contraction and loading of a joint during weight bearing cause compression stresses in joints.

- 압박력은 근육이 수축하여 관절이 움직일때 주어지는 압박부하 힘. 

3. Shear: a force applied parallel to the cross-sectional area of the tissue.

- 전단력

4. Strain: the amount of deformation or lengthening that occurs when a load (stress) or stretch force is applied.

- 응력 : 부하가 주어져 조직의 길이가 변화하는 양

Regions of the Stress-Strain Curve

1. Toe region. 

That area of the stress–strain curve where there is considerable deformation without the use of much force is called the toe region. This is the range where most functional activity normally occurs. Collagen fibers at rest are wavy and are situated in a three-dimensional matrix, so some distensibility in the tissue occurs by straightening and aligning the fibers.

- 힘-응력 커브 초기에 약간의 힘이 주어져 조직이 늘어나는 지점. 

- 이는 대부분 기능적 활동에서 필요한 정상영역임. 

2. Elastic range/linear phase. 

Strain is directly proportional to the ability of tissue to resist the force. This occurs when tissue is taken to the end of its ROM, and gentle stretch is applied. With stress in this phase the collagen fibers line up with the applied force, the bonds between fibers and between the surrounding matrix are strained, some microfailure  between the collagen bonds begins, and some water may be displaced from the ground substance. There is complete recovery from this deformation, and the tissue returns to its original size and shape when the load is released if the stress is not maintained for any length of time (see the following discussion on creep and stress relaxation for prolonged stretch).

- 조직에 지속적인 부하가 주어져 직접적으로 변화한 응력의 비율. 

- 관절의 rom과 부드러운 스트레칭의 힘이 주어질때 발생하는 늘어남. 

- 이때 콜라겐 섬유는 주어진 힘으로 섬유와 주위 기질사이에 결합이 line up됨. 

3. Elastic limit. 탄성한계

The point beyond which the tissue does not return to its original shape and size is the elastic limit. 

4. Plastic range 가소성 범위

The range beyond the elastic limit extending to the point of rupture is the plastic range. Tissue strained in this range has permanent deformation when the stress is released. In this range there is sequential failure of the bonds between collagen fibrils and eventually of collagen fibers. Heat is released and absorbed in the tissue. Because collagen is crystalline, individual fibers do not stretch but, instead, rupture. In the plastic range it is the rupturing of fibers that results in increased length.

- 탄성한계를 넘어서 파손지점까지를 가소성 범위라고 함. 

- 열이 방출되고 조직에서 흡수됨. 콜라겐은 crystalline이므로 각각의 섬유는 늘어나지 않고 파열됨. 가소성 범위를 넘어서면 길이가 늘어남. 

5. Ultimate strength 최종강도

The greatest load the tissue can sustain is its ultimate strength. Once this load is reached, there is increased strain (deformation) without an increase in stress required. The region of necking is reached in which there is considerable weakening of the tissue, and it rapidly fails.

- 조직이 파열되지 않는 최대 부하는 최종강도라고 함. 이 부하에 도달하면 변형이 증가하고 ... 이후 necking 부위에 도달후 파열됨. 

The therapist must be cognizant of the tissue feel when stretching because as the tissue begins necking, if the 

stress is maintained, there could be complete tearing of the tissue. Experimentally, maximum tensile deformation of isolated collagen fibers prior to failure is 7% to 8%. Whole ligaments may withstand strain of 20% to 40%.116 

- 치료사는 조직의 necking지점을 잘 알아야 함. 만약 스트레스가 지속되면 조직이 완전파열될 수 있기 때문에.. 실험적으로 최대 장력 변형은콜라겐 파열전 7-8%임. 인대는 20-40%의 응력을 견딜 수 있음. 

6. Failure. 

Rupture of the integrity of the tissue is called failure.

7. Structural stiffness. 

Tissues with greater stiffness have a higher slope in the elastic region of the curve, indicating that there is less elastic deformation with greater stress. Contractures and scar tissue have greater stiffness, probably because of a greater degree of bonding between collagen fibers and their surrounding matrix.

- 구축과 반흔조직은 강한 stiffness를 가짐. 

Connective Tissue Responses to Loads

1. Creep 변형력

When a load is applied for an extended period of time, the tissue elongates, resulting in permanent deformation (Fig. 4.7A). It is related to the viscosity of the tissue and is therefore time-dependent. The amount of deformation depends on the amount of force and the rate at which the force is applied. Low-magnitude loads, usually in the elastic range and applied for long periods, increase the deformation of connective tissue and allow gradual rearrangement of collagen fiber bonds (remodeling) and redistribution of water to surrounding tissues.33,94,140,142

- 부하가 신장을 위한 일정시간동안 주어질때, 조직은 늘어나고 결국 영원한 변형이 초래됨. 이는 조직의 점성과 연관되고 결국 시간의존적임. 변형의 정도는 힘의 양과 비율에 의존함. ....

Increasing the temperature of the part increases the creep and therefore the distensibility of the tissue.89,150,153 Complete recovery from creep may occur over time, but not as rapidly as a single strain. Patient reaction dictates the time a specific load is tolerated. 

2. Stress-relaxation 스트레스-이완

When a force (load) is applied to stretch a tissue and the length of the tissue is kept constant, after the initial creep there is a decrease in the force required to maintain that length, and the tension in the tissue decreases33 (Fig. 4.7B). This, like creep, is related to the viscoelastic qualities of the connective tissue and redistribution of the water content. 

- 힘이 적용되어 조직이 늘어날때, 초기 변형력후에는 조직의 길이는 영원히 유지됨. 

Stress-relaxation is the underlying principle used in prolonged stretching procedures where the stretch position is maintained for several hours or days. Recovery (i.e., no change) versus permanent changes in length is dependent on the amount of deformation and the length of time the deformation is maintained.33

3. Cyclic loading and connective tissue fatigue. 

Repetitive loading of tissue increases heat production and may cause failure below the yield point. The greater the applied load, the fewer number of cycles needed for failure. This principle can be used for stretching by applying repetitive

(cyclic) loads at a submaximal level on successive days. 

- 조직에 주어지는 반복적인 부하는 열을 생성하고 결국 항복지점에 이름. ...

The intensity of the load is determined by the patient’s tolerance. A minimum load is required for this failure. Below the minimum load an apparently infinite number of cycles do not cause failure. This is the endurance limit. Examples of connective tissue fatigue from cyclic loading are stress fractures and overuse syndromes, neither of which is desired as a result of stretching. Therefore, periodically, time is allowed between bouts of cyclic stretching to allow for remodeling and healing in the new range.

Summary of Mechanical Principles for Stretching Connective Tissue

1. Connective tissue deformation (stretch) occurs to different degrees at different intensities of force. It requires breaking of collagen bonds and realignment of the fibers for there to be permanent elongation or increased flexibility. Failure of tissue begins as microfailure of fibrils and fibers before complete failure of the tissue occurs. Complete tissue failure can occur as a single maximal event (acute tear from a traumatic injury or manipulation that exceeds the failure point) or from repetitive sub maximal stress (fatigue or stress failure from cyclic loading). Microfailure (needed for permanent lengthening) also occurs with creep, stress-relaxation, and controlled cyclic loading.

2. Healing and adaptive remodeling capabilities allow the tissue to respond to repetitive and sustained loads if time is allowed between bouts. This is important for increasing both flexibility and tensile strength of the tissue. If healing and remodeling time is not allowed, a breakdown of tissue (failure) occurs as in overuse syndromes and stress fractures. Intensive stretching is usually not done every day in order to allow time for healing. If the inflammation from the microruptures is excessive, additional

scar tissue is laid down, which could become more restrictive.33 

3. It is imperative that the individual use any newly gained range to allow the remodeling of tissue and to train the muscle to control the new range, or the tissue eventually returns to its shortened length.

Changes in Collagen Affecting Stress–Strain Response

1. Effects of Immobilization

There is weakening of the tissue because of collagen turnover and weak bonding between the new, non stressed fibers. There is also adhesion formation because of greater cross-linking between disorganized collagen fibers and because of decreased effectiveness of the ground substance maintaining space and lubrication between the fibers.41,142

- 조직에 부하가 주어지지 않으면 콜라겐 turnover가 발생하여 조직은 약화됨. 

The rate of return to normal tensile strength is slow. For example, after 8 weeks of immobilization, the anterior cruciate ligament in monkeys failed at 61% of maximum load; after 5 months of reconditioning, it failed at 79%; after 12 months of reconditioning, it failed at 91%.114,115 There was also a reduction in energy absorbed and an increase in compliance (decreased stiffness) prior to failure following immobilization. Partial and near complete recovery followed the same 5-month and 12-month pattern.115

- 정상 장력으로 돌아오는 시간은 느리고 오래걸림. 예를들어 원숭이의 전십자인대를 8주 고정한 후에 최대부하의 61%가 약해짐. 5개월의 재활후에 79%까지 회복함. 12개월 후에 91%까지 회복함. 

2. Effects of Inactivity (Decrease of Normal Activity)

There is a decrease in the size and amount of collagen fibers, resulting in weakening of the tissue. There is a proportional increase in the predominance of elastin fibers, resulting in increased compliance. Recovery takes about 5 months of regular cyclic loading. Physical activity has a beneficial effect on the strength of connective tissue.

- 정상활동의 감소

- 콜라겐 양과 크기가 감소하여 조직의 약화를 초래함. 

3. Effects of Age

There is a decrease in the maximum tensile strength and the elastic modulus, and the rate of adaptation to stress is slower.116 There is an increased tendency for overuse syndromes, fatigue failures, and tears with stretching.166 

나이 영향

- 나이가 증가함에 따라 최대장력, 탄성력이 감소함. 

4. Effects of Corticosteroids

There is a long-lasting deleterious effect on the mechanical properties of collagen with a decrease in tensile strength.166 There is fibrocyte death next to the injection site with delay in reappearance up to 15 weeks.116

스테로이드 영향

- 스테로이드는 오랜기간 콜라겐의 기계적 특성에 악 영향을 초래하여 장력을 약화시킴. 

5. Effects of Injury

Excessive tensile loading can lead to rupture of ligaments and tendons at musculotendinous junctions. Healing follows a predictable pattern (see Chapter 10), with bridging of the rupture site with newly synthesized type III collagen. This is structurally weaker than mature type I collagen. Remodeling progresses, and eventually collagen matures to type I. Remodeling usually begins about 3 weeks post-injury and continues for several months to a year, depending on the size of the connective tissue structure and magnitude of the tear.60

손상의 영향

- 과도한 장력부하는 인대와 건의 파열을 초래할 수 있음. 치유는 콜라겐 type3 로 재생되어 연결함. 이것은 구조적으로 type 1 콜라겐보다 약함. 재생과정은 type 1 콜라겐으로 대치되는 것인데, 이는 3주후부터 몇개월-1년까지 소요됨. 

[비누방울]

스트레칭 치료와 Muscle spindle, Golgi tendon organ과의 관계... 역시 어렵네요...

[문형철]

ㅎㅎㅎ
드디어 거의 완벽에 가까운 이해에 도달함 ㅎㅎㅎㅎ

[박수홍]

읽기 스트레칭과 연부조직원리

[여인호]

읽기

[이상진]

감사합니다..