I wanted to do a newer article this week reviewing Oliver et al. (2023) The Relationship Between Stride Mechanics and Shoulder Distraction Force in Collegiate Softball Pitchers. They studies studied 63 NCAA Division I softball pitchers to find out whether the way they stride during a pitch affects the amount of force placed on their shoulder. Each pitcher threw three full-speed fastballs while being tracked with an electromagnetic motion-capture system that recorded body and joint movement at 100 Hz. Sensors were attached to different parts of the body to measure stride length, stride foot position, and shoulder distraction force (the force pulling the shoulder away from the body). Stride length was calculated as a percentage of each athlete’s height, and shoulder force was measured during the acceleration phase of the pitch (from foot contact to ball release). The data were analyzed using correlations and regression analysis to see if stride mechanics predicted shoulder stress. They found:
- Stride length and shoulder distraction force were positively related
- Longer strides = higher shoulder distraction force
- Stride length explained 11% of the variation in shoulder force (R² = .11, p = .009)
- For every 10% increase in stride length (relative to body height), shoulder force increased by 0.94 N/kg
- Stride foot position (open vs closed) did NOT significantly relate to shoulder force (p = .456)
Implications: The researchers concluded that pitchers who take longer strides during the windmill motion tend to place more stress on their shoulder. This supports earlier research showing that longer strides can increase ball speed but may also increase injury risk. Since only 11% of shoulder force was explained by stride length, the authors note that many other factors—like trunk rotation, timing, strength, or mechanics—must also play a role. They were surprised that stride foot position didn’t matter for shoulder force, especially since it does influence injury risk in baseball. This suggests softball pitching may involve different upper-body mechanics than baseball. The main takeaway is that coaches and athletes should understand that increasing stride length might boost performance but may also raise the risk of shoulder pain or injury.
Also…
This was super cool and super nerdy. This post discussed energy systems and how they are trained and measured. I am always looking at different things and understanding the energy systems of softball can help you train the athlete, advise them to eat and be in better overall SOFTBALL shape. Also, William Wallace is a sweet name for a PhD in exercise science!