근 긴장도(muscle tone)의 생체역학적 기능

[문형철]

근육 긴장도(muscle tone)는 두가지에 의해 영향을 받는다.

1. 결합조직에 의한 점탄성(viscoelasticity) 

  - 근막의 기능, 근막경선의 기능과 관련된 긴장도(특히 중요한 것은 perimysium의 passive muscle stiffness가 아닐까?)

2. 근육조직에 의한 수축과 이완

- 주로 TrP에 의한 경직된 띠(taut band)에 의해 영향

- 사용제한(immobilization)에 의한 섬유성 변화(fibrosis)에 의해서 영향

결국 근 긴장도는 움직임과정에서 중요한 결합조직의 점탄성과 근육의 수축이완에 영향을 미침으로써 전신 움직임, 전신 골격계의 틀어짐과 연관되어지는 무서운 결과를 초래한다. 

The etiology and terminology of muscle tone is full of controversies, partly because various authors' definitions of muscle tone differ. Therefore, a detailed differential diagnosis has to be made among others because each condition requires a different type of treatment (2). Unfortunately, a precise and adequate analysis is often neglected. An imprecise diagnosis results in disappointing therapeutic results. Unfortunately, the detailed physiology of muscle tone is unknown and studies of muscle tone changes caused by altered or impaired function have not been studied sufficiently in the laboratory or in the clinic.

In principle it is necessary to differentiate whether the main changes occur in the connective tissue of the muscle (viscoelastic properties) or in over-activation of the contractile components of the muscle (contractile properties). According to Mense and Simons, "Muscle tension depends physiologically on 2 factors: the basic viscoelastic properties of the soft tissues associated with the muscle, and/or the degree of activation the contractile apparatus of the muscle" (9). In the former, we speak about muscle tightness, stiffness, loss of flexibility, or extensibility (length), and

in the latter, it is a real increase of muscle contractile activity such as in spasmodic torticollis or trismus.

In principle, with respect to viscoelastic changes, the muscle gets shorter at rest (decreased extensibility), either because of shortening of contractile muscle fi bers or because of retraction of the connective tissue within the muscle and the adjacent fascia. With respect to contractile changes, the increased muscle tone may involve the majority of muscle fibers of the muscles or only a limited number as found as "taut bands" in trigger points.

Clinically, resting muscle tone presents a combination of both situations (contractile and viscoelastic properties), and it is the role of the clinician to establish an appropriate diagnosis (9). However, measuring muscle tone objectively presents a dilemma. 

Tests of viscoelasticity involve measurements of the velocity of motion, viscosity, thixotropy, and resonant frequency when load is gradually applied (9). Tests of contractile activity are simpler in that EMG can be used; however, this is not without inherent difficulties, as in trigger points where only small loci in the muscle show increased electrical activity (9).

A detailed differential diagnosis of muscle tone is necessary for the proper treatment approach, and this can be accomplished by a combination of inspection and palpation (Table 10.1). Layer palpation of the skin, subcutaneous tissue, fascia, fat, and any other structure in the area concerned, although purely subjective is a practical clinical tool and with much practice and experience, detecting the type of muscle tone present in the concerned area can be skillfully achieved. Inspection of posture, movement patterns, and gait  also yields invaluable clinical information about the

underlying source of increased muscle tension.

[heoss]

감사합니다.^^

[P.T.이강진]

좋은 내용 감사합니다^^

[문형철]

1. 결합조직에 의한 점탄성(viscoelasticity)
- 근막의 기능, 근막경선의 기능과 관련된 긴장도(특히 중요한 것은 perimysium의 passive muscle stiffness가 아닐까?)

2. 근육조직에 의한 수축과 이완
- 주로 TrP에 의한 경직된 띠(taut band)에 의해 영향
- 사용제한(immobilization)에 의한 섬유성 변화(fibrosis)에 의해서 영향