The Assessment of Shoulder Function by Measurement of Muscle Strength using Handy Dynamometer Micro FET.

Abstract

[Purpose] The purpose of this study was to find out if a Micro FET is a useful device for detecting the shoulder functions of patients with a rotator cuff tear. We examined the relationships between the area of the rupture of the rotator cuff, the pre-and post operative functions and the muscle power of the shoulder joint.
[Materials and Methods] We investigated 18 patients who could be observed for more than a year after their operations. There were 17 males and 1 female, whose average age was 60.7 years.
After arthoroscopic subacromial decompression, arthoroscopic repair of the rotator cuff was performed on 6 patients, performed in 6 patients, an open repair on 10 patients, and Teflon patching on 2 patients.
The average length of follow-up was 12.9 months.
The muscle strength was measured by usin g a Micro FET in the following positions:
(1)with shoulder joint abduction at 90° in the scapular (90° abduction),
(2)45° abduction with the thumb down (45° abduction), and (3)external rotation with the arm hanging at the side.
We also evaluated the unaffected sides then we ratioe d the affected sides to the unaffected sides.
The area of the cuff tear was measured at operation time.
[Results] Before the operations there were no significant correlation between the area of the cuff tear and the preoperative Micro FET values and the JOA score. But the Micro FET values (90° abduction,45° abduction) significantly correlated with the total JOA scores and the functional parameters. Postoperatively, the Micro FET values correlated with the total JOA scores and the functional parameters significantly.
[Conculusion] Micro FET values obtained at 90° abduction are useful to evaluate shoulder function pre and postoperatively.