J Sports Med 2002 May-Jun;30(3):374-81
The most effective exercise for strengthening the supraspinatus muscle: evaluation by magnetic resonance imaging.
Takeda Y, Kashiwaguchi S, Endo K, Matsuura T, Sasa T.
of Orthopaedic Surgery, Tokushima Red Cross Hospital, 28-1 Shinbiraki,
Chuden-cho, Komatsushima City, Tokushima 773-8502, Japan.
Electromyography has been used to determine the best exercise for
strengthening the supraspinatus muscle, but conflicting results have been
reported. Magnetic resonance imaging T2 relaxation time appears to be more
accurate in determining muscle activation. PURPOSE: To determine the best
exercises for strengthening the supraspinatus muscle. STUDY DESIGN: Criterion
standard. METHODS: Six male volunteers performed three exercises: the empty
can, the full can, and horizontal abduction. Immediately before and after each
exercise, magnetic resonance imaging examinations were performed and changes
in relaxation time for the subscapularis, supraspinatus, infraspinatus, teres
minor, and deltoid muscles were recorded. RESULTS: The supraspinatus muscle
had the greatest change among the studied muscles in relaxation time for the
empty can (10.5 ms) and full can (10.5 ms) exercises. After the horizontal
abduction exercise the change in relaxation time for the supraspinatus muscle
(3.6 ms) was significantly smaller than that for the posterior deltoid muscle
(11.5 ms) and not significantly different from that of the other muscles
studied. CONCLUSION: The empty can and full can exercises were most effective
in activating the supraspinatus muscle.