An 8-week lumbopelvic-hip strength training intervention effectively improved trunk-rotation strength and power and ball speed in adolescent pitchers but increased elbow stress, underscoring the importance of reducing pitch counts or extending rest periods as ball speed increases.
Key Findings
Results
The 8-week intervention produced greater improvements in trunk-rotation strength and power in the intervention group compared to the control group.
54 high school pitchers were enrolled into intervention (n≈27, age = 15.6 ± 1.5 years) or control (n≈27, age = 16.0 ± 1.0 years) groups
Both groups performed 8-week training targeting lumbopelvic-hip muscles
Between-group differences in trunk-rotation strength and power were statistically significant: F(1,44) range 6.12–11.44, P range .002–.02
The intervention group showed greater improvements across multiple trunk-rotation strength and power measures
Results
Ball speed increased significantly more in the intervention group compared to the control group.
Between-group difference in ball speed was statistically significant: t(45) = 2.37, P = .014
This finding suggests lumbopelvic-hip strength training translates to improved pitching velocity in adolescent pitchers
This result is consistent with prior literature linking lumbopelvic-hip training to increased ball speed
Results
The intervention resulted in a significant increase in elbow-varus moment, indicating greater elbow stress.
Between-group difference in elbow-varus moment: t(45) = 2.06, P = .046
Increased elbow stress accompanied the gains in ball speed
Authors note this finding 'underscores the importance of reducing pitch counts or extending rest periods as ball speed increases'
This raises injury risk concerns for adolescent pitchers who increase velocity without corresponding reductions in workload
Results
No significant between-group differences were observed in pitching kinematic changes as a whole.
The intervention produced 'only limited changes in pitching kinematics'
Changes in trunk kinematics (e.g., pelvis rotation, trunk-separation angle) did not differ significantly between groups overall
Authors suggest combining strength training with technical feedback and extending intervention duration may lead to greater biomechanical adaptations
Results
Within the intervention group, improvements in trunk-rotation strength and power were correlated with beneficial changes in pitching trunk kinematics.
Greater trunk-rotation strength and power improvements were associated with smaller pelvis rotation (more 'closed' pelvis) at lead-foot contact
Improvements were also correlated with smaller trunk-separation angle at lead-foot contact
Improvements were correlated with later timing of peak upper torso-rotation velocity
Correlation magnitudes: |r| = 0.436–0.566
These associations were only observed within the intervention group and did not translate to significant between-group kinematic differences
Methods
The study sample consisted of 54 high school pitchers with similar anthropometric characteristics between groups.
Intervention group: age = 15.6 ± 1.5 years, height = 1.76 ± 0.07 m, mass = 72.0 ± 14.3 kg
Control group: age = 16.0 ± 1.0 years, height = 1.76 ± 0.12 m, mass = 76.4 ± 11.4 kg
Study design was a controlled laboratory study conducted in a research laboratory/training facility
Outcome measures included lumbopelvic-hip muscle function, trunk kinematics during pitching, joint loading, and ball speed
What This Means
This research suggests that an 8-week exercise program targeting the core and hip muscles (the lumbopelvic-hip region) can meaningfully improve rotational strength, power, and pitching velocity in teenage baseball pitchers. Fifty-four high school pitchers were divided into an intervention group and a control group, both of which completed 8 weeks of training. The intervention group showed significantly greater gains in trunk-rotation strength and power, and threw the ball faster by the end of the study.
However, the increased ball speed came with a notable downside: the intervention group also experienced greater stress on the elbow joint, as measured by a biomechanical variable called elbow-varus moment. This is a known risk factor for elbow injuries in pitchers. The study also found that while overall pitching mechanics did not change dramatically between groups, pitchers within the intervention group who improved the most in strength and power tended to show more favorable mechanics, such as keeping the pelvis more 'closed' at a key moment in the pitching motion and better sequencing of upper-body rotation.
This research suggests that strength training alone may not be sufficient to improve pitching mechanics broadly — technical coaching and feedback may also be needed. More importantly, it highlights a practical concern: as young pitchers throw harder due to strength gains, they may be at greater risk for arm injuries if pitch counts and rest periods are not adjusted accordingly. Coaches, parents, and athletes should be aware that getting stronger and faster does not automatically make pitching safer.
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Oyama S, Palmer T, Laudner K. (2026). Effects of an 8-Week Core Training Program on Lumbopelvic-Hip Muscle Function and Pitching Biomechanics in Adolescent Pitchers.. Journal of athletic training. https://doi.org/10.4085/1062-6050-0674.25