摘要：The ability to measure the stretc h-shorten ing cycle of isolate d mu scle gro ups is limited.The purpo se of th is stu dy was to measure the stretch -sho rte ning cycle of shou lder intern al rot ato rs.Sixty-eight volun teers,35 men and 33 women,par ticipa ted in the test ses sion.A conce ntric con traction of the dominant int ern al rotat or was measured for peak torq ue,power and acceleration time on a Cybex NORM isokinetic dynam om eter un de r three conditions:1) Concentric contraction only,2) Isometric preload before a concentric contraction,and 3) Eccentric preload before a conc entric contraction.Condition 3 displayed significant inc rea se in peak torque pro duc tion com pared to condition 1 (p<0.001).Condition s 2 an d 3 revealed significant inc rease in power pro duction com pared with condition 1 (p<0.0001 and p<0.003 respectively).A significan t difference was found in all thr ee c ond itions betwee n genders,with the men pro ducing higher peak to rque and power scores.
