Lack of Proprioceptive Strategy Modulation Leads to At-Risk Biomechanics for Anterior Cruciate Ligament in Healthy Athletes.

INTRODUCTION: Anterior cruciate ligament (ACL) injuries are frequent in handball and altered sensory integration may contribute to increased injury risk. Recent evidence showed that proprioceptive postural control strategies differ among athletes. The aim of this study was to evaluate the relationship between proprioceptive strategy and biomechanics during side-cutting manoeuvres.

METHODS: 47 handball players performed anticipated (CUT ant ) and unanticipated (CUT unant ) cutting tasks. Their postural proprioceptive strategy was then characterised according to the perturbation of the centre of pressure displacement generated by the muscle vibration on a firm and foam surface. Individuals able to reweight proprioception from ankle to lumbar signals according to the stability of the support were defined as flexible. Conversely, athletes maintaining an ankle steered strategy on foam surface were characterised as rigid . Statistical Parametric Mapping analysis was used to compare pelvic and lower limb side-cutting kinematics, kinetics and electromyography activity from 7 muscles 200 ms before and after initial contact (IC) using a two-way Analysis of Variance (group×condition).

RESULTS: 20 athletes (11 females and 9 males, 18.5 years) were characterized as flexible and 20 (12 females and 8 males, 18.9 years) as rigid. No interaction between condition and proprioceptive profile was observed. More ipsilateral pelvic tilt prior IC and lower vastus lateralis (VL) activity immediately after IC was observed during CUT ant . When comparing proprioceptive strategy, rigid individuals exhibited less pre-activity of the semitendinosus ( P < 0.001) and higher VL activity ( P = 0.032). Conversely, rigid showed higher gluteus medius pre-activity ( P < 0.05) and higher VL activity 100 ms after IC ( P < 0.001). Ankle was also more internally rotated before and during the stance phase ( P < 0.05) among rigid athletes.

CONCLUSIONS: Rigid handball players exhibited at-risk determinants for ACL injuries during side-cutting manoeuvres.