Does Chronic Ankle Instability Influence Knee Biomechanics of Females during Inverted Surface Landings?

Abstract

The primary purpose of the study was to determine whether atypical knee biomechanics are exhibited during landing on an inverted surface. A seven-camera motion analysis system and two force plates were used to collect lower extremity biomechanics from two groups of female participants: 21 subjects with chronic ankle instability (CAI) and 21 with pair-matched controls. Subjects performed ten landings onto inverted and flat platforms on the CAI/matched and non-test limbs, respectively. Knee and ankle joint angles, joint angular displacements, joint moments and eccentric work were calculated during the landing phase and/or at the initial contact. Paired t-tests were used to compare between-group differences (p<0.05). We observed that CAI group displayed a significantly increased knee flexion angle, knee flexion displacement, peak knee extension moment and internal rotation moment, and eccentric work in the sagittal plane, possibly due to altered ankle biomechanics. Participants with CAI employed some compensatory strategy to improve their ankle and postural stability during landing onto the tilted surface. The increased knee extension and internal rotation moments of CAI participants could potentially result in a greater ACL loading. In future studies, it may be worthwhile to measure or estimate the ACL loading to confirm whether CAI could relate to the mechanism of ACL injury.

Chronic Ankle Instability Does Not Influence Tibiofemoral Contact Forces during Drop Landings

“…No group-difference in peak values was found, which could indicate that the CAI group likely experienced similar peak ACL loadings versus controls. Previous studies [5,6] have observed greater knee extension and internal rotation moment, greater rectus femoris activation, but less biceps femoris activation, and suggest these altered knee biomechanics and muscle activations of CAI could relate to the increased ACL loading. However, this may not be true based on our tibiofemoral contact force data.…”

“…However, this may not be true based on our tibiofemoral contact force data. The possible reason was that the CAI group also exhibited a greater knee flexion angle [5] that could decrease the tibial anterior shear force by decreasing the patella tendon-tibia shaft angle [9,10]. Therefore, it is still unclear whether CAI could increase the ACL loading during landings.…”

“…Other studies observed some knee biomechanical alterations of CAI that could potentially relate to the knee injury mechanism during landings. These alterations of CAI, compared with controls, included reduced knee flexion angles [4], greater knee extension and internal rotation moments [5], and higher quadriceps to hamstrings activation ratio [6].…”

Unilateral jump landing neuromechanics of individuals with chronic ankle instability

“…Thirty-two individuals with CAI and thirty-one healthy controls (matched according to age, sex and body mass index) were recruited among students and staff of the XXXX in XXXX, but also through the university's outpatient podiatry clinic and advertisement on social media. The sample size was determined a-priori from two previous studies that assessed jump landing kinematics and EMG on an inclined surface 15,16 with G-Power software (Version 3.1, Kiel, Germany). It was determined that for ankle inversion, peroneus longus preactivation and knee flexion, a total of 38 to 58 participants was necessary to obtain alpha, beta and Cohen's d effect size of respectively 0.05, 0.2 and 0.75 to 0.94.…”

Lower Limb Biomechanics During Drop-Jump Landings on Challenging Surfaces in Individuals With Chronic Ankle Instability

“…During landing on more challenging surfaces such as unstable 13 or inclined, [13][14][15] altered lower limb biomechanics could place individuals with CAI at greater risk of sustaining recurrent LAS. Indeed, previous studies that quantified lower limb biomechanics during unilateral drop jump landing on an inclined surface (WEDGE) showed a longer peroneus longus activation latency, 14,15 reduced peroneus longus activation, 13,15,16 reduced gluteus medius muscle activation 13 and greater ankle inversion angles 14,15,17 in individuals with CAI compared to healthy counterparts. During unilateral drop jump landing on an unstable surface (FOAM), greater ankle dorsiflexion angles were reported between participants with CAI and healthy controls.…”