Rabbit hindlimb kinematics and ground contact pressure during the stance phase of hopping gait

Though the rabbit is a common animal model in musculoskeletal research, there is very limited data reported on healthy rabbit biomechanics. Our objective was to quantify the normative hindlimb biomechanics of six New Zealand White rabbits (3 male, 3 female) during the stance phase of hopping gait. We measured biomechanics by synchronously recording sagittal plane motion and ground contact pressure using a video camera and pressure mat, respectively. Both foot angle (i.e., angle between foot and ground) and ankle angle curves were unimodal. The peak ankle dorsiflexion angle was 65.9{degrees}{+/-}12.7{degrees} and occurred at 39% stance, while the peak ankle plantarflexion angle was 136.9{degrees}{+/-}7.8{degrees} at toe-off. Minimum and maximum foot angles were 16.6{degrees}{+/-}6.4{degrees} at 12% stance and 125.4{degrees}{+/-}4.0{degrees} at toe-off, respectively. During stance, the knee joint center gradually progressed 4.7 cm downward and 18.1 cm forward, on average. The maximum vertical ground reaction force and contact area, both averaged across rabbits, were 42.5 {+/-} 11.4 %BW and 7.5 {+/-} 1.8 cm2, respectively. Our study confirmed that rabbits exhibit a plantigrade gait pattern, similar to humans. Future studies can reference our data to quantify the extent to which orthopedic interventions affect rabbit biomechanics.