Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Health and Rehabilitation Sciences

Supervisor

Dr Jayne Garland

Abstract

Purpose: To investigate whether a single session of closed kinetic chain (CKC) and open kinetic chain (OKC) exercises emphasizing speed post-stroke could evoke changes in the motor control and whether these improvements would transfer to postural tasks.

Methods: Thirty-two individuals post-stroke and 32 age- and sex- matched controls performed a single session of 50 fast squats and steps (Chapter 3). Internal perturbations (arm raise/load drop) were used to assess postural responses before exercises (Pre), immediately after exercises (Post) and 15 minutes after exercises (Retention) (Chapter 4). Eleven individuals post-stroke performed a single session of 50 fast knee and ankle OKC exercises and postural responses were assessed Pre and Post exercises (Chapter 5). Electromyographic (EMG) activity was measured bilaterally in the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and soleus (SOL) muscles.

Result: The squat was performed slower in the stroke group than controls, with impaired temporal coupling between the knee movement and postural sway. The paretic BF EMG was delayed with a reduced slope and the paretic RF EMG area was reduced. The squat was initiated with the non-paretic leg as a compensatory strategy in the low motor recovery group whereas the paretic leg was used in an adaptive manner in the high motor recovery group (Chapter 2). The temporal coupling improved and EMG area of the paretic TA, BF and RF increased in the squats. In the steps, the paretic BF and RF EMG area increased in the stepping leg and the paretic SOL and RF EMG area increased in the stance leg (Chapter 3). The paretic BF EMG area and slope increased after exercises in the arm raise task. In the load drop task, the paretic BF EMG deactivation improved and was retained after 15 minutes. Weight bearing symmetry also improved with exercise (Chapter 4). The paretic BF, RF, TA EMG area increased along with an increase in peak velocity and power during the OKC exercises. The arm acceleration and BF EMG area increased in the arm raise task (Chapter 5).

Conclusion: This dissertation reveals the positive effects of exercise emphasizing speed on motor control post-stroke.


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