The effect of experimentally-induced gluteal muscle paralysis on joint kinematics, reaction forces and dynamic balance performance during lunges.

INTRODUCTION

Lunges are commonly used in resistance training and rehabilitation as functional closed kinetic chain exercises. The gluteal muscles play a critical role in stabilizing the hip and pelvis during such movements.

RESEARCH QUESTION: How does selective experimentally-induced gluteal muscle paralysis affect joint kinematics, joint reaction forces (JRFs), and dynamic balance during lunge performance?

METHODS

Ten healthy adults underwent sequential blocks of 1) branch of the superior gluteal nerve to the tensor fasciae latae (SGNtfl) muscle, 2) superior gluteal nerve (SGN), and 3) inferior gluteal nerve (IGN) on the dominant right leg. Participants performed forward lunges under control and post-block conditions. Kinematic data were recorded using a 3D motion capture system, ground reaction forces were collected via dual force plates, and joint reaction forces were estimated using musculoskeletal modeling.

RESULTS

For the affected right leg leading the lunge, SGN and IGN blocks resulted in a significantly higher lunge position (SGN: + 45 mm; IGN: + 33 mm), driven by reduced right knee and ankle flexion and diminished left hip extension. Following the SGN block, pelvic flexion and rotation toward the affected (right) side were observed. JRFs were significantly reduced in the right hip, knee, and ankle (average maximum difference hip: 100 % BW, knee: 200 % BW, ankle: 50 % BW).

CONCLUSION

Despite altered mechanics and reduced joint loading following selective gluteal paralysis, participants were able to complete the lunge task, even if the lunge position was higher, and compensatory pelvic flexion and rotation towards the affected side occurred.