The purpose of the Janes et al. (2017) Fast-Pitch Softball Players Use Biomechanical Compensations to Maintain Pitch Speed When Fatigued was to determine how fatigue affects pitching mechanics, strength, and pitch performance in fast-pitch softball pitchers. Eight healthy high school pitchers between the ages of 15 and 18 completed a simulated game consisting of 125 pitches. Measurements were collected on the first pitch and again on the 125th pitch. An eight-camera motion capture system tracked body movements using 36 reflective markers placed on anatomical landmarks. Researchers measured joint positions at push-off, foot contact, and ball release. Shoulder strength was measured with a handheld dynamometer, while fatigue and pain were assessed using the Borg Rating of Perceived Exertion and a visual analog pain scale. Pitch speed was also recorded. The researchers compared measurements before and after the simulated game to identify changes caused by fatigue.
They found:
Pitch Speed
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Pitch speed did not significantly change from Pitch 1 to Pitch 125 (p = .63).
Pitchers maintained their velocity even after throwing 125 pitches.
Fatigue
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Perceived fatigue increased significantly throughout the simulated game (p = .01).
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Although pitchers felt much more fatigued, they continued throwing at the same speed.
Fatigue increased even though performance stayed the same.
Shoulder Strength
Pitchers experienced significant decreases in:
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Shoulder internal rotation strength
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Shoulder external rotation strength
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Shoulder flexion strength
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Scapular plane abduction strength
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Upper, middle, and lower trapezius strength (p values = .001–.041).
The muscles responsible for stabilizing and moving the shoulder became weaker after pitching.
Elbow Strength
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Elbow flexion strength also decreased, although the change was not statistically significant (p = .062).
Biomechanical Changes
As fatigue developed, pitchers changed their mechanics by:
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8° less pelvic lateral rotation at landing (p = .048)
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11° less elbow flexion at ball release (p = .027)
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A trend toward greater knee flexion at ball release (6° increase; p = .072).
Pitchers altered both lower-body and upper-body mechanics to maintain performance.
Kinetic Chain Relationships
Changes in elbow flexion were strongly related to changes in:
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Thorax lateral rotation (r = .717)
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Pelvic lateral rotation (r = .830)
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Pelvic tilt (r = –.774)
The entire kinetic chain changed together rather than one joint changing independently.
Pain
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None of the pitchers reported pain during the simulated game despite measurable fatigue and strength losses.
Implications: The authors concluded that high school softball pitchers are able to maintain pitch velocity even when they become fatigued, but they do so by changing their pitching mechanics. As shoulder strength declined and fatigue increased, pitchers compensated by using less elbow flexion and altering pelvic movement during the pitch. Because these mechanical changes were linked across the pelvis, trunk, and arm, the findings suggest that fatigue affects the entire kinetic chain rather than just the throwing arm. These compensations may help pitchers continue performing during a game, but they could also increase stress on other parts of the body, especially the lower back and lower extremities, potentially raising the risk of overuse injuries over time. The authors emphasize that these biomechanical changes can occur during a typical game, even when athletes do not report pain, and recommend additional research to determine whether pitch-count limits should be considered for softball pitchers.
Key Takeaways
This study provides strong evidence that:
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Pitchers maintain velocity despite fatigue.
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They accomplish this by making biomechanical compensations, not by maintaining their original mechanics.
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Fatigue causes measurable reductions in shoulder strength, but the body adapts by changing movement patterns throughout the kinetic chain.
Important Biomechanics Connection
This study fits the kinetic-chain model well. As the shoulder muscles fatigued, pitchers did not lose pitch speed. Instead, they adjusted pelvic motion and elbow position to compensate for the loss of strength. These findings support the idea that fatigue alters movement strategies throughout the kinetic chain rather than affecting only the throwing arm. For ground reaction forces and segment sequencing, this reinforces the concept that when one part of the chain becomes less effective, other segments change their mechanics to preserve performance. While these compensations may help maintain velocity in the short term, they may also increase cumulative stress on the shoulder, trunk, and lower extremities, contributing to overuse injuries over a season.
Also…
I love my podcasts and I heard one from The Patrick Jones Podcast that I really loved. The recent podcast with Cam Lanzilli was really good and discussed a bunch of different pitching-specific topics. I recommend you check it out.
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