This study aimed to investigate the recovery process of shoulder joint range of motion and lower limb muscle flexibility after pitching.
The participants were two pitchers (28 and 38 years old) who belonged to an adult club team. The measurement site was the pitching space in the hospital rehabilitation room. After warming up sufficiently, the participants threw 120 pitches as hard as they could. Medical checks were conducted every 30 pitches thrown. Participant safety was considered.
The following aspects were examined: (1) second external rotation angle of the shoulder joint (ER2), (2) second internal rotation angle of the shoulder joint (IR2), (3) Straight Leg Raising test (SLR) for axial leg/tread leg, and (4) Heel-Buttock Distance test (HBD) for axial leg/tread leg. These parameters were measured before, after, a day after, three days after, and five days after pitching. The value before pitching was set to 100, and each measurement was calculated as a percentage.
The study results (before, after, one day after, three days after, and five days after pitching, respectively (%)), are as follows:
(1) ER2, Participant A: 100, 108, 113, 112, 109; Participant B: 100, 118, 114, 114, 114.
(2) IR2, Participant A: 100, 120, 164, 140, 136; Participant B: 100, 92, 76, 79, 105.
The shoulder second external rotation ROM increased after pitching and required more than five days for recovery.
(3) SLR (axial leg/tread leg), Participant A: 100/100, 116/95, 122/83, 115/93, 123/95; Participant B: 100/100, 100/106, 107/112, 109/115, 111/108.
(4) HBD (axial leg/tread leg), Participant A: 100/100, 42/88, 75/100, 33/125, 33/100; Participant B: 100/100, 119/100, 157/125, 143/100, 114/88.
After pitching, Participant A had a decreased step leg SLR and Participant B had a higher HBD, which required more than five days to recover from.
The increased second shoulder external rotation ROM suggests that pitching may cause shoulder joint instability, which may require more than five days of recovery. In terms of flexibility of the lower limb muscle groups, subject A showed decreased hamstrings of the stepping leg, whereas subject B exhibited decreased quadricep muscles bilaterally. This indicates that different muscle groups experience stress differently depending on the pitching form.
The instability of the external rotation of the shoulder and stiffness of the lower limb muscle groups occur after more than 100 pitches are thrown; they require more than five days recovery. Therefore, we believe that aftercare, such as shoulder joint stability exercises and stretching of the lower limb muscles, is necessary to prevent pitching disorders.
We believe that aftercare, such as shoulder joint stability exercises and stretching of the lower limb muscles, is necessary to prevent pitching disorders.
Pitching form
Baseball Players
