Biceps Tendon Changes in Youth Softball Pitchers Following an Acute Bout of Pitching

Because pitch counts do not exist for softball, pitchers may throw between 1200 and 1500 pitches over 3-day tournaments. With this workload, a common symptom among softball pitchers is anterior shoulder pain. The purpose of this study was to examine long-head biceps tendon (LHBT) changes in youth softball pitchers following an acute bout of pitching. Nineteen softball pitchers (11.89 +/- 1.2 years; 158.23 +/- 9.71 cm; 61.59 +/- 14.76 kg) participated. Images of the LHBT were obtained prior to and immediately following a simulated game protocol. Repeated-measures MANOVA was used to determine if there was a difference in LHBT size before and after the simulated game protocol. There were significant increases in both transverse thickness (t18 = -2.76, p = 0.013, 95 % confidence interval = -0.050 to -0.007) and longitudinal thickness (t18 = -2.64, p = 0.016, 95 % confidence interval = -0.060 to -0.007) of the LHBT following an acute bout of pitching. Longitudinal and transverse thickness of the biceps tendon significantly increases following an acute bout of softball throwing. These changes may indicate an inflammation response of the biceps tendon and the biceps pulley.