The Longitudinal Application of Biomechanical Biofeedback on Whole Limb Complex Motor Skill Development
Creators: name: Author, Unknown
Publisher: name: University of Lincoln
Year: 2023

description: The provision of augmented feedback using biomechanical measures, termed biofeedback (BFb), both guides and reinforces skill development. Previous BFb research has; mostly used simple skills that do not transfer to complex skills, focused on single joints thus missing BFb influence on other variables within the kinematic chain, and omitted long-term retention testing so learning is not assessed. Therefore, using 3 themes, the aim of this thesis was to identify the effectiveness of knowledge of performance (KP) BFb on influencing a whole limb complex motor skill, and assess longitudinal retention. Theme 1 identified biomechanically relevant task dynamics, using the fencing attacking lunge as a vehicle for analysis. Differences between skilled (n=7) and novice (n=8) fencers in the rear leg kinematic chain identified skilled displayed greater proximal-to-distal extension angular velocity (skilled, 1.9±0.7, 6.0±2.4, 9.1±2.1 for hip, knee and ankle; novice, 2.4±0.9, 4.6±1.3, 5.4±2.9 rad·s-1; p&lt;0.05) and greater normalised horizontal impulse (skilled 2.51±0.25; novice 1.92±0.36 Ns·kg¯¹); p&lt;0.05), and that ankle plantarflexion correlated with peak horizontal force (r=0.81; p&lt;0.05). Findings from Theme 1 informed a visual, KP intervention for Theme 2 to assess the effectiveness of an intervention applied to a whole limb technique. Novice participants randomized to BFb (n=16) and Control groups (n=16) visited the laboratory on three occasions over one week, and returned for retention testing at 4-6weeks. Findings indicated that KP on whole limb kinematic extension angular velocities, and sequential patterning of joints, was effective in manipulating the whole limb kinematic chain in a novel lunge task. Angular velocities significantly increased at post testing by 34±38%, 25±24% and 33±47% for the hip, knee and ankle in the BFb group versus no significant change of 9±29%, 6±20% and 8±28% in Controls. There were no changes in any external kinetics, and no correlation between ankle plantarflexion and any external kinetic measures for the 4416 lunges. Theme 3 examined learning through a dynamical systems framework, exploring coordination during a longitudinal, 26-week KP intervention using a fading schedule (i.e. increasing time between visits). Kinematic changes occurred within just two visits, and were retained throughout the intervention for the BFb group. Coordination coupling of both the hip-knee and knee-ankle angular-velocities, quantified using a modified vector coding (VC) method, did not change in both groups (p&gt;0.05). Given known limitations of VC, a new coupling-area based method was developed (CI2Area) to quantify longitudinal coordination-variability. BFb participants demonstrated a continual increase in coordination-variability, shown by the positive gradient of CI2Area over the 26-weeks for the BFb versus negative gradient for Controls (hip-knee BFb 0.7, Control -0.9; knee-ankle BFb 3.14, Control -0.24). In addition to the group effect, 9 individuals who had a CI2Area greater than the upper 95%CI of the Control group’s gradient were considered to have responded to the BFb. In conclusion, this thesis contributes to the body of knowledge, using the developed CI2Area as a new method to explore learning in whole-limb complex tasks. This research demonstrated that a fading BFb KP intervention is effective for long-term learning and changes are achieved quickly in targeted variables.