Pull-down exercises and the subacromial space
The smallest distance between the acromion and the humeral head is called the acromio-humeral distance (AHD).
Past studies have found that compared to healthy individuals, patients with subacromial pathology, there is a reduction in AHD of 1.9 mm and 2.1mm with those that have rotator cuff tears and rotator cuff dysfunction, respectively.
Hence, for this study, the authors set a 2 mm change post intervention as clinically relevant.
The study included 20 healthy subjects (5 males and 15 females) who underwent ultrasound imaging of their shoulder while doing isometric pull-downs of various resistance with the shoulder in 90 forward flexion and elbow in 90 flexion.
The results revealed that in males, both the dominant and non-dominant arms at various resistance levels showed an increase of more than 2 mm of AHD with the pull-down motion. However, in female subjects, no significant results were demonstrated.
Despite the greater portion of subjects being females who did not demonstrate significant changes, the authors concluded that isometric pull-down exercises increased AHD in flexed shoulder positions in healthy subjects.
Subsequently, they also concluded that pull-down exercises may benefit patients with subacromial pain syndrome.
> From: Sealey et al., Physiotherapy 103 (2018-03-02 09:17:50) 208-213. All rights reserved to Elsevier Ltd.. Click here for the online summary.