Oxygen uptake kinetics measured at the onset of comfortable self-paced walking in elderly women after hip fracture.
The objectives of this study were to (1) evaluate the suitability of "comfortable" self-paced walking as a mode of exercise to study VO(2) kinetics, and (2) to investigate VO(2) kinetics after hip fracture using self-paced walking as the exercise mode. The study took place in a Scottish rehabilitation hospital physiotherapy gymnasium [hip fracture (HF) group] and a Scottish University Gymnasium [young (Y) and healthy elderly (HE) groups]. Fifteen women after HF (median age 81 years) and five Y and five older HE women (median ages 22 and 78 years, respectively) took part in the study. Volunteers completed three repeats of 3 min of "comfortable" self-paced walking on two occasions. The ensemble averaged VO(2) response from walks 2 and 3 on visits 1 and 2 were combined and characterised using nonlinear regression techniques to derive a Mean Response Time (MRT). Self-paced walking was described as "constant-load" exercise (coefficient of variation of lap speeds of <or=6%) in 13 of 15 cases in the HF group on at least one visit (100% of cases in Y and HE groups). Steady-state VO(2) was achieved in 3 min in 8 of HF group on Visit 1 and 10 on Visit 2 (100% of cases in Y and HE groups). MRTs for the HF group (51 s, N = 5, 4 repeats; N = 7, 2 repeats) were significantly higher than the Y and HE groups [Y group 22 s (N = 5, 4 repeats); HE group 36 s (N = 5, 4 repeats)]. Self-paced walking provided a suitable mode of exercise to investigate VO(2) kinetics in frail older women after HF and permitted the first characterisation of VO(2) kinetics in this patient group. This test provides a promising methodology to evaluate rehabilitation efforts in frail individuals.
Fitzsimons
Claire
C
Sport, Culture and the Arts and SIPBS, University of Strathclyde, Glasgow, UK. claire.fitzsimons@strath.ac.uk
Simpson
Hamish
H
Young
Archie
A
Greig
Carolyn
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006620:Hip Fractures; D006801:Humans; D017063:Outcome Assessment, Health Care; D010101:Oxygen Consumption / Q000502:physiology*; D012044:Regression Analysis; D016138:Walking / Q000502:physiology*