Three dimensional knee joint kinematics and lower limb muscle activity of anterior cruciate ligament deficient knee joint participants wearing a functional knee brace during running.

摘要

Background. Knee braces have been found to provide limited stability to the ACL deficient knee in situations where the knee is loaded during sporting movements. Different adaptation strategies have been found between patients that can cope with the injury and patients that cannot. One of the expected changes can be muscle activation characteristics of the injured knee during strenuous activity with and without a functional knee brace.; Methods. Three dimensional (3D) kinematic and electromyography (EMG) data were collected from each participant for ten consecutive gait cycles during running on a treadmill under both braced and unbraced conditions. Participants were administered the "Knee Outcome Survey Activities of Daily Living Scale" to distinguish functional and non-functional candidates.; Findings. No significant differences on 3D kinematics and EMG data were noted between functional and non-functional participants, thus data analysis focused on comparisons of bracing conditions for one combined group. Bracing significantly increased total range of motion in the sagittal plane (p0.05) and reduced total range of motion in the transverse plane (p0.05). Muscle activity at heel-strike showed a consistent trend to increase for the hamstrings and decrease for the quadriceps under the braced when compared to the unbraced condition.; Interpretations. Our findings indicated that bracing the ACL deficient knee altered kinematics of the injured leg while running. Tendencies towards reductions in quadriceps and increases in hamstrings activity at heel-strike provides added stability to the injured knee. These changes to bracing further support the mechanical and the proprioceptive contributions of the functional knee brace to protect the ACLD knee.