Fig. 2
From: Impaired contractile function of the supraspinatus in the acute period following a rotator cuff tear
Maximal isometric force is lower in tenotomized supraspinatus at 2D and 15D. a Apparatus to measure muscle in vivo contractility and susceptibility to injury in the supraspinatus muscle. The insertion of the supraspinatus was released and the tendon tied to a load cell. The suprascapular nerve was stimulated via subcutaneous needle electrodes to activate the supraspinatus maximally. A series of maximal twitches was used to determine optimal length (Lo) and the force-frequency relationship was determined to obtain maximal isometric force. b When compared to control, the mean of maximal isometric force per group was 30% lower at 2D and 20% lower at 15D. Maximal force was not different between the tenotomized groups. All data are presented as mean ± SD, p < 0.05. *, indicates statistical significance compared to control