The scapula plays a crucial role in proper shoulder function, contributing to
synchronized scapular rotation during humeral motion, serving as a stable base for
rotator cuff activation, and acting as a key link in the kinetic chain. Each of these
functions is essential for optimal arm movement and depends on the integrity of the
surrounding shoulder anatomy. However, bone and soft tissue damage, as well as muscle
weakness and shortening, can alter the scapula's roles, affecting both its resting
position and dynamic motion. This altered scapular position and/or motion is referred to
as scapular dyskinesia.
Although scapular dyskinesia is commonly observed in shoulder injuries, it is generally
considered a nonspecific response to shoulder pain rather than a direct consequence of a
specific glenohumeral pathology. Therefore, assessing the presence or absence of scapular
dyskinesia is a critical component of clinical evaluation. A comprehensive assessment
should include a visual examination of the scapula at rest and during dynamic humeral
movements, as well as objective measurements of posture and the performance of scapular
corrective maneuvers. These evaluations assist clinicians in determining the extent to
which scapular involvement contributes to a given shoulder injury.
The treatment of scapular dyskinesia should begin with optimizing anatomical alignment,
followed by restoring dynamic scapular stability through the strengthening of scapular
stabilizers using kinetic chain-based rehabilitation protocols. The kinetic chain, as
defined by Steindler, is "a combination of successive joints containing complex motor
units." It describes the interconnected movement of joints, where adjacent segments
interact to form a continuous chain of motion. This biomechanical model emphasizes that
dysfunction in any part of the chain can impact movement quality in both upper and lower
segments. The scapula is a foundational component within this system, with surrounding
muscles playing a crucial role in stabilizing it.
Postural disorders such as kyphosis can lead to scapular deformities, negatively
affecting scapular stability. Rehabilitation professionals and researchers increasingly
use the Scapular Muscular Endurance Test (SMET) to assess scapular stability. Given that
adolescents are at a heightened risk for musculoskeletal injuries, upper extremity
assessments like the SKET may contribute significantly to evaluating this population.
However, the validity and reliability of the SMET in adolescents have yet to be
established.
This study aims to determine the validity and reliability of the SKET in adolescents.