A study of antagonist/agonist isokinetic work ratios of shoulder rotators in men who play badminton.
METHODS
Normative descriptive study.


OBJECTIVE
Exploring the isokinetic work ratios of eccentric antagonist/concentric agonist shoulder rotators in the late cocking and deceleration phases of a forehand overhead smash in badminton players. Comparing the work ratios between dominant and nondominant shoulders.


BACKGROUND
The strength of shoulder muscles for badminton players has been studied but there is little information on the work output of these muscles for a specific range of movement.


METHODS
Twenty-five skilled men who play badminton at club level with a mean age of 29.4 years (SD = 6.1) were measured for concentric and eccentric isokinetic work (joules) of shoulder internal (IR) and external (ER) rotators on both upper extremities at 120 degrees/s. Bilateral isokinetic work ratios for eccentric IR/concentric ER between 60 degrees and 90 degrees of shoulder external rotation were calculated to denote strength profile in the late cocking phase of the badminton smash. Work ratios for eccentric ER/concentric IR between 10 degrees external rotation and 30 degrees internal rotation were calculated to denote strength profile in the deceleration phase of the badminton smash. The respective work ratios were compared between both shoulders.


RESULTS
The eccentric IR/concentric ER work ratios in late cocking were 1.9:1 and 1.3:1 (P = 0.001) for the dominant and nondominant shoulders, respectively. The eccentric ER/concentric IR work ratios in the deceleration phase were 1.1:1 and 1.3:1 (P = 0.003) for the dominant and nondominant shoulders, respectively.


CONCLUSIONS
The work ratios of eccentric antagonist/concentric agonist are different between dominant and nondominant shoulders of skilled badminton players. Rehabilitation for injuries of these athletes should aim at developing the optimal antagonist/agonist work ratios to return them to this sport.
Ng
Gabriel Y F
GY
Department of Rehabilitation Sciences, Hong Kong Ploytechnic University, Hung Hom, Kowloon. rsgng@polyu.edu.hk
Lam
Patrick C W
PC
D000328:Adult; D006801:Humans; D007700:Kinetics; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D015865:Racquet Sports / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D017006:Rotator Cuff / Q000502:physiology*; D012785:Shoulder Joint / Q000502:physiology*