Evaluation of the Kinetic Chain in Little League Elbow

Abstract

This study is to evaluate the abnormalities in the kinetic chain in the players with little league elbow during the medical screening of middle school baseball teams. Ninety-three players were examined with elbow ultrasonography in the field. Using kinetic chain evaluation test, 27 players sonogrphically diagnosed of little league elbow in dominant arm were compared with 25 players who were normal as control. Scapular-spine distance, horizontal flexion test, combined abduction test, and glenohumeral internal rotation deficit were used for evaluating kinetic chain in the upper extremities, while tightness of quadriceps and hamstring muscles, internal rotation of stance leg, and external rotation of stride leg were used for lower extremities. Also, the single leg stance test and finger-floor distance were used for core stability and flexibility. Twenty-five of 27 players (93%) having little league elbow showed kinetic chain abnormalities of either upper or lower extremities or trunk. This rate was significantly higher for the players having the little leaguer’s elbow than control (28%) (p=0.017). Each specific tests for evaluating kinetic chain were also more prevalent in little league elbow group than control, and the abnormalities in the upper extremity were more common than those in lower extremity (p=0.026). Combined abduction test (23/27) and limitation of internal rotation of stance leg (16/27) were the most prevalent abnormalities in upper and lower extremity test, respectively. Our findings showed that there are many abnormalities in kinetic chain in players having the little league elbow and it may be associated with pathogenesis of little league elbow.