Grip strength, muscle soreness and pain threshold perception evolution in baseball pitchers in a simulated 75-pitch game: a repeated measures study.

Background/aim: In baseball pitching, neuromuscular fatigue and its manifestations on muscle strength, muscle soreness and pain perception affect pitching performance. The purpose of this study was to quantify the evolution of grip strength, muscle soreness and pain threshold perception and pitching velocity in baseball pitchers throughout a simulated 75-pitch game.

Methods: 30 high-level amateur male baseball pitchers were recruited. Repeated measure analysis of covariance with age as a covariate (p<0.05) was used to identify significant differences across blocks of pitches for grip strength, muscle soreness, pain threshold perception and pitching velocity.

Results: Dominant arm grip strength (55.67±12.32 kg to 48.62±12.25 kg ; -12.66%) and pitching velocity (119.87±8.00 km/hour to 118.75±6.90 km/hour ; -0.93%) declined while muscle soreness perception increased in dominant arm forearm flexors (1.65±1.16 to 4.19±2.02 ; 25.38%), biceps (1.81±1.39 to 4.31±1.85 ; 25%) and non-dominant arm forearm flexors (1.38±1.10 to 2.12±1.63 ; 7.31%) across the pitching blocks (p<0.05).

Conclusion: In summary, a pitch count of 75 fastball pitches triggered an acute decline in grip strength combined with an increase in muscle soreness perception of the throwing arm in baseball pitchers.