Functional isokinetic strength ratios in baseball players with injured elbows.
BACKGROUND
Elbow injuries are widely reported among baseball players. The elbow is susceptible to injury when elbow-flexor and -extensor forces are imbalanced during pitching or throwing. Assessment of muscle-strength ratios may prove useful for diagnosing elbow injury.


OBJECTIVE
The purpose of this study was to assess the relationship between the elbow-flexor and -extensor functional isokinetic ratios and elbow injury in baseball players.


METHODS
Retrospective study.


METHODS
Biomechanics laboratory.


METHODS
College baseball players with (n = 9) and without (n = 12) self-reported elbow pain or loss of strength were recruited.


METHODS
Trials were conducted using a dynamometer to assess dominant-arm flexor and extensor concentric and eccentric strength at angular velocities of 60 degrees and 240 degrees/s. Functional isokinetic ratios were calculated and compared between groups.


RESULTS
Regression analysis revealed that a ratio of biceps concentric to triceps concentric strength greater than 0.76 (the median value) significantly predicted elbow injury (P = .01, odds ratio of injury = 24). No other ratios or variables (including position played) were predictive of injury status.


CONCLUSIONS
These findings suggest that the ratio of biceps concentric to triceps concentric functional strength strongly predicts elbow-injury status in baseball players. Assessment of this ratio may prove useful in a practical setting for training purposes and both injury diagnosis and rehabilitation.
Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Gueishan Township, Taiwan.
Yin-Chou
YC
Lin
Angela
A
Thompson
Jung-Tang
JT
Kung
Liang-Wei
LW
Chieh
Shih-Wei
SW
Chou
Jung-Charng
JC
Lin
D001265:Athletic Injuries / Q000453:epidemiology*; D001484:Baseball / Q000293:injuries*; D001696:Biomechanical Phenomena; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D019415:Torque; D055815:Young Adult; D000092464:Elbow Injuries