Exploring the Inter-relationship Between Cognitive and Motor Function in People with Lower Limb Amputations
Abstract
The main objective of the present dissertation was to expand our understanding of the inter-relationship between cognition and mobility in people with lower limb amputations (PLLA). Study 1 systematically reviewed the literature to assess the effects of dual-task testing on the balance and gait of PLLA. A total of twenty-two studies were included. Overall, PLLA demonstrated a disproportionately greater dual-task effect than controls, characterized by increased sway velocity and reduced pace and rhythm, and increased asymmetry when balance or walking was paired with a secondary task. Additionally, the dual-task effect was not influenced by differences in etiology, level of amputation, or experience with a prosthesis. Study 2 examined the association between balance confidence, a proposed cognitive distractor, and basic walking abilities in community-dwelling people with unilateral transtibial level amputations. Forty-four people participated in Study 2, completing a questionnaire on balance confidence and an assessment of functional mobility. This study concluded that decreased balance confidence was independently associated with a longer time to complete the functional mobility test in both the single-task and dual-task conditions. Study 3 evaluated the association of cognitive function on tests of physical function in PLLA at discharge from inpatient prosthetic rehabilitation. Tests included examinations of global cognitive status, processing speed, executive function, and balance confidence. Physical function was assessed through gait velocity, dynamic balance, and functional mobility. Data from twenty-two participants demonstrated that better global cognitive status and executive function were independently associated with faster gait velocity and greater functional mobility for both conditions of single-task and dual-task, yet this was not observed for dynamic balance. Moreover, no association was observed between processing speed and balance confidence and any of the tests evaluated. PLLA are optimal candidates for dual-task balance and gait research as they are often being cognitively and physically challenged during ambulation with a prosthesis. The present findings are novel and provide evidence on the interplay between cognition and mobility in PLLA. Further research studies examining cognitive-motor capacity and its relationship to important markers of rehabilitation progress and future success are warranted in this group of people.