The effect of proprioception on physical function

Résumé fourni par la source

Proprioception, the spatial and mechanical state of the body and its musculoskeletal parts, is critical for normal movement and to interact with the external world. Proprioceptive abilities decline with age, and proprioceptive deficits are common in neurological conditions such as, stroke, Parkinson’s disease and multiple sclerosis. This thesis provides novel insights into key aspects of “low-level” and “high-level” proprioception and the impact proprioceptive deficits have on physical function in individuals with neurological conditions and healthy individuals across the adult lifespan. In Chapter 2, the accuracy, precision, and the central calibrations that govern proprioceptive judgements were compared at two different body parts - the hand and the jaw in 30 healthy individuals. Low-level proprioceptive judgements were more accurate than high-level proprioception judgements at both the jaw and hand. For the hand, judgements were more precise in the low-level condition. However, precision was similar across the low- and high-level conditions for the jaw. Comparing the regression lines for the hand and jaw conditions indicates the brain does not appear to apply a similar calibration to make high-level proprioceptive judgements with these distinct yet functionally related body parts. In Chapter 3, I present the results from a systematic review of 56 studies to evaluate the magnitude of association between proprioceptive ability and physical function in people with stroke, Parkinson’s disease and multiple sclerosis. Overall, people with neurological conditions that have better proprioceptive abilities tend to also have better physical function - 92% of associations were positive. However, the magnitude of association between proprioceptive ability and physical function varied widely both within and between studies and ranged from -0.31 to 0.93 (r and ρ). When studies discussed their measures of association, 50% used language which implied causality. This chapter provides recommendations for the field to move forward - modern statistical approaches such as causal inference are needed to determine whether proprioceptive abilities have causal effects on physical function in people with neurological conditions. In Chapter 4, I used a causal inference framework to investigate the effect of low- and high-level proprioceptive ability on upper limb function across the adult lifespan in 184 healthy individuals. Overall, imprecise high-level proprioceptive judgements cause impaired upper limb function, and this effect worsens with age. In summary, this thesis provides direct evidence that decline in high-level proprioceptive abilities impair upper limb function. These results provide a strong basis for novel interventions to improve proprioceptive abilities and ultimately, improve physical function.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.