A new musculoskeletal assessment in a student population.

A common finding in repetition activities (typing, running, swimming . . .), are overuse syndromes arising from a mechanical imbalance affecting overstressed soft tissues and joints. A more subtle corollary, occasioned by a sedentary life-style, is an imbalance between postural and phasic muscle groups leading to joint dysfunction. Postural and phasic muscles as defined by V Janda (New Zealand Manip Ther Assoc Tech Newsletter 2: 1-3, 1977) interplay in complex patterns which determine strength and coordination for normal function. Joint pathology, and central or peripheral nervous system impairment, all lead to compensatory changes in the muscle function, namely the tendency for postural muscles to become tight and for phasic muscles to weaken. Faulty posture through muscle imbalance compromises joint mechanics predisposing to dysfunction. Appropriate management of musculoskeletal disorders should recognize the role of imbalance between postural and phasic muscles in both the etiology and sequelae of the disorder. A musculoskeletal examination of 35 students was undertaken to develop assessment skills, devise a recording form, and refine a test sequence to assist data collection. The principal finding of tightness in postural muscles is consistent with the theory that these muscles undergo adaptive shortening. This survey provided the opportunity to examine the incidence of muscle imbalance in a young adult population and to prepare guidelines for future study. J Orthop Sports Phys Ther 1986;8(1):34-41.