Contribution of Lower Limb Joint Movement in Adapting to Re-establish Step Length Symmetry During Split-Belt Treadmill Walking

Abstract

People walking on a split-belt treadmill, where each belt moves at a different speed, adapt step length to re-establish symmetry. However, kinematic changes that occur when re-establishing step length symmetry have not yet been clarified. This study aims to clarify the changing lower limb joint kinematics of each leg when re-establishing step length symmetry. We examined ten young adults who walked on a double-belt treadmill under symmetric and asymmetric conditions of belt velocity using a motion capture system. The results showed that the hip flexion angle at heel strike on one side was not significantly different between the symmetric and asymmetric conditions (p = 0.38) thereby demonstrating that the hip flexion angle of the leading leg re-established symmetry at heel strike (HS) of the fast and slow sides. However, the knee extension angle of the leading leg expanded asymmetrically at HS on both sides. The shank of the fast leg possibly accelerated more to move the heel further forward. The results indicated that subjects with limited knee extension function must increase their hip flexion movement of the fast-side limb to accelerate the shank in the swing phase. The present study suggests securing the range of motion and treatment of the knee extension to reduce the spasticity of hamstrings or plantarflexor before split-belt training. Moreover, split-belt training may be undesirable for improving step length symmetry in impaired subjects who are unlikely to improve the function of knee extension movement. The present study contributes toward developing a rehabilitation protocol that improves the gait asymmetry of patients through split-belt training.

Effects of arm swing amplitude and lower limb asymmetry on motor variability patterns during treadmill gait

“…Second, we saw some changes at the hip and ankle that were not observed at the knee, suggesting that attention is directed more to joints with larger kinematic redundancies. Of note, these observations were at a lower asymmetry ratio (0.8:1) relative to the 1:2 ratio often employed in split-belt gait assessments (Hirata et al, 2019;McFadyen et al, 2009), indicating that even minor asymmetries can alter lower limb motor variability in healthy young adults. Our findings could be amplified in older adults, as healthy males and females aged 73.4 ± 4.7 years adapted less and more slowly to asymmetric gait induced by a split-belt treadmill than young adults (Bruijn et al, 2012).…”

Motion Symmetry Evaluation Using Accelerometers and Energy Distribution

“…The analysis of motion symmetry has a wide range of applications in rehabilitation, physical therapy, biomedicine and neurology allowing us to detect natural differences between the movement of the left and right limbs during walking, running or cycling [1][2][3], to study the dependence of motion symmetry on mental and environmental conditions and to enable early diagnostics of possible neurological disorders. This multidisciplinary area combines the knowledge and use of different sensor systems, wireless communication links and computational intelligence methods to detect appropriate features and process signals recorded by selected multichannel systems.…”

Motor Adaptation Effect of Active Joint Movement During Cycling Generated by Ankle Assist Ergometer: A Proof-of-Concept Study in Healthy Participants

“…During the split-belt treadmill task, leg multi-joint movement adapts to the continuous disturbance caused by the double belt, eliciting new leg movements as an adaptive change [14]. The total involvement of the cortical process is relatively larger at the beginning of adaptation to the splitbelt-induced perturbation.…”