062 - Trunk Tension, Poor Control: The Risk in Resistance
It’s easy to assume that more challenge equals better results. But when the movement foundation is poor, even well-intentioned resistance-based training can lead to breakdown instead of build-up.
This study dives into how adding multiplanar trunk resistance impacts dynamic postural control in athletes with low-quality movement, particularly during high-risk tasks like single-leg jumping.
If you work with athletes, operators, or rehab clients with less-than-ideal control, this one’s a must-read.
What They Found:
Researchers studied 24 female collegiate athletes with poor movement quality, as defined by the Single-Leg Squat Test. Each participant performed sets of single-leg vertical jumps under two conditions:
No external load
With multiplanar trunk resistance (elastic bands at 6% of body mass)
Key outcome variables included:
Center of Pressure (COP) displacement, velocity, and variability (RMS)
Peak vertical ground reaction force
Results:
Anteroposterior (AP) control improved: COP displacement, velocity, and variability decreased (p < 0.01), suggesting greater control.
Mediolateral (ML) control worsened: COP metrics increased (p < 0.05), indicating poorer balance side-to-side.
Peak vertical force did not change, ruling out a stiffer or “rigid” landing pattern.
What This Means:
Trunk resistance training during jumping might improve sagittal plane control but compromise frontal plane stability in athletes with poor motor control. In practical terms:
Better forward-backward alignment
Worse side-to-side wobble—especially important given the lateral trunk flexions often linked to ACL injuries
If you're training tactical professionals with suboptimal control or rehabbing after injury, introducing trunk resistance without mastering base movement quality may backfire.
Tactical Implications:
Assess Before You Load: Use tests like the Single-Leg Squat or Y-Balance to screen for movement competency before adding complexity.
Build Lateral Control First: If ML sway increases with load, focus early training on frontal plane stability (e.g., lateral step-downs, side planks).
Progress with Purpose: Multiplanar trunk resistance may be too advanced for athletes with movement deficits; start with low-speed, low-load tasks.
Use Feedback Tools: Monitor side-to-side sway or use force plates to detect unseen instability during advanced drills.
Questions To Consider:
Are you adding complexity too early in athletes with poor control?
Could your well-designed loading actually be increasing injury risk?
What strategies do you use to identify and regress athletes with compromised lateral stability?
How do you cue and train trunk control in multi-directional environments?
Are your “core” drills preparing athletes for real-world deceleration?
Cantusio, L. M., Ribeiro, R., Misuta, M., & Sarro, K. J. (2024). How the multiplanar trunk resistance affects the dynamic postural control during single-leg vertical jumps in college athletes with poor movement quality. Brazilian Journal of Motor Behavior, 18(1), e385. https://doi.org/10.20338/bjmb.v18i1.385