This case series measured isokinetic protraction and retraction force in the shoulder girdle of 19 overhead athletes with unilateral impingement. Simultaneous EMG recorded the three trapezius portions and serratus anterior. It asks whether the injured side differs from the healthy contralateral side.
When you evaluate an overhead athlete with impingement, remember the problem often lives at the scapulothoracic joint, not just under the acromion. This paper shows the injured side loses protraction power (serratus anterior) and underactivates the lower trapezius during retraction, while upper and middle trapezius stay normal.
The deficits appeared only at high velocity, so testing or rehabbing only at slow speeds can miss the problem. Think power, not just strength. Mechanistically, painful conditions inhibit the serratus anterior and lower trapezius, disrupting the force couple that controls scapular rotation and dynamic glenohumeral stability.
Clinically, this supports targeted scapular stabilization as part of conservative management of secondary impingement. As a case series using the contralateral limb as control (n=19), it is hypothesis-generating, not definitive.
This case series measured isokinetic protraction and retraction force in the shoulder girdle of 19 overhead athletes with unilateral impingement. Simultaneous EMG recorded the three trapezius portions and serratus anterior. It asks whether the injured side differs from the healthy contralateral side.
When you evaluate an overhead athlete with impingement, remember the problem often lives at the scapulothoracic joint, not just under the acromion. This paper shows the injured side loses protraction power (serratus anterior) and underactivates the lower trapezius during retraction, while upper and middle trapezius stay normal.
The deficits appeared only at high velocity, so testing or rehabbing only at slow speeds can miss the problem. Think power, not just strength. Mechanistically, painful conditions inhibit the serratus anterior and lower trapezius, disrupting the force couple that controls scapular rotation and dynamic glenohumeral stability.
Clinically, this supports targeted scapular stabilization as part of conservative management of secondary impingement. As a case series using the contralateral limb as control (n=19), it is hypothesis-generating, not definitive.