Influence of Proprioceptive Reweighting Ability on Lower-limb Biomechanics During Functional Tasks

Anterior cruciate ligament (ACL) injuries are frequent in handball especially among young players. Recent investigations highlighted the implication of the central nervous system as a potential risk factor for ACL rupture.

The ability to dynamically reweight proprioceptive signals according to postural conditions is crucial for balance control.

The aim of this study is therefore to investigate the influence of proprioceptive reweighting on biomechanical determinants of ACL loads during functional tasks and unplanned side cutting manoeuvers.

Team Handball is a traumatic sport, especially regarding anterior cruciate ligament (ACL) injuries. Young females are more vulnerable as they are 3 to 5 times more likely to sustain an ACL rupture compare to males.

Several anatomical, biomechanical and sensorimotor risk factors have been clearly identified, however the implication of the central nervous system was recently highlighted. Indeed, it has been shown that individuals who will suffer of ACL ruptures exhibited a decreased functional connectivity between brain regions responsible for postural control and sensorimotor processing. Due to the unanticipated situations that occurred during game situations, the role of the brain (i.e neural control) is now advocated to explain sensorimotor errors leading to injuries during complex tasks such as faking an opponent. Muscle vibration is a reliable tool to assess proprioceptive integration during postural control. The ability to shift from one proprioceptive cue to another when postural conditions are changing is crucial. This dynamic reweighting process allow to obtain an optimal postural control. However, recent investigations revealed that this process is altered among symptomatic populations, elderly patients or even under fatigue conditions. More precisely, some individuals seem able to shift proprioceptive reliance while other doesn't. To our knowledge, no studies have investigated the link between proprioceptive reweighting and biomechanical determinants of ACL loads during functional tasks. Thus, the aim of this study is to compare lower-limb biomechanics during unanticipated side cutting manoeuvres and single leg drop vertical jump among young handball players according to their ability to reweight proprioceptive signals.

Eligibility Criteria:
Inclusion Criteria:

* Aged from 15 to 25 years
* Intensive training handball practice for at least two years, mastering the technical gesture of unplanned sidestep cutting manoeuvre
* Training volume of 5 hours minimum per week
* Signature of the consent (participants and parents for minors)

Exclusion Criteria:

* Recent osteoarticular pathology (i.e. less than three months) of the lower limbs, whether traumatic or not
* Unfit to consent or refusal to participate in the study
* Obvious standing balance disorder or disabling neurological pathology
* Pain of the musculoskeletal system (joint, tendon or muscle) permanent or during exercise
* Fatigue (evaluation using the Borg scale) during the clinical examination (\> 6) prior to performing the sporting gesture
* Known skin allergy to any adhesive product