Electronic Thesis and Dissertation Repository


Doctor of Philosophy


Health and Rehabilitation Sciences


Dr. Tom J Overend



PURPOSE: The purpose of this study was to evaluate the effect of fluid loss following hemodialysis (HD) on tibialis anterior (TA) strength in participants with end-stage renal disease. Issues concerning measures of skeletal muscle hydration and efficacy of exercise as an anabolic intervention were also addressed.

METHODS: Data from published literature were combined in a meta-analysis to establish efficacy of exercise in participants on HD. Three clinical studies were undertaken using data acquired from healthy volunteers and participants on HD. Hydration of the calf muscles was estimated using bioelectrical impedance spectroscopy (BIS) [extracellular (ECF) and intracellular (ICF) fluid] and magnetic resonance imaging (MRI) [transverse relaxation time constants (T2) and apparent diffusion coefficient (ADC)] acquired measures. Reliabilities and associations between the measures acquired using these two techniques were established using intraclass correlations and linear regression analyses. The maximal voluntary isometric contraction (MVIC) strength of TA was measured using a dynamometer.

RESULTS: A significant reduction (p2 shortened by 2.38ms; 95%CI: 1.04, 3.71) of TA, and calf ICF by 0.05 liters (95%CI: 0.01, 0.08) were observed between before and after HD measurements. In comparison with control group, participants on HD had significantly (p2 of TA was significantly (p2 of TA (β = 0.44, p=0.042), medial gastrocnemius (β = 0.47, p=0.027) and ADC of lateral gastrocnemius (β = 0.6, p= 0.003) after HD only; hence these measures could not be used interchangeably as measures of TA interstitial fluid.

CONCLUSION:We observed reduction in strength (~6%) and volume (~ 15%) of TA following HD. Further research is required to evaluate the impact of myocellular lipids and muscle architecture on estimates of ECF and MVIC of TA for establishing absolute or relative effects of fluid loss on TA muscle volume and strength.