What Is the Most Effective Eccentric Stretching Position in Lateral Elbow Tendinopathy?

Background A variety of treatment options suggest that the optimal treatment strategy for lateral elbow tendinopathy (LET) is not known, and further research is needed to discover the most effective treatment for LET. The purpose of the present study was to verify the most effective position of eccentric stretching for the extensor carpi radialis brevis (ECRB) in vivo using ultrasonic shear wave elastography. Methods A total of 20 healthy males participated in this study. Resting position was defined as 90° elbow flexion and neutral position of the forearm and wrist. Elongation of the ECRB was measured for four stretching maneuvers (forearm supination/pronation and wrist extension/flexion) at two elbow angles (90° flexion and full extension). The shear elastic modulus, used as the index of muscle elongation, was computed using ultrasonic shear wave elastography for the eight aforementioned stretching maneuverangle combinations. Results The shear elastic modulus was the highest in elbow extension, forearm pronation, and wrist flexion. The shear elastic moduli of wrist flexion with any forearm and elbow position were significantly higher than the resting position. There was no significant difference associated with elbow and forearm positions except for elbow extension, forearm pronation, and wrist flexion positions. Conclusions This study determined that elbow extension, forearm pronation, and wrist flexion was the most effective eccentric stretching for the ECRB in vivo.