Treadmill exercise rehabilitation improves ambulatory function and cardiovascular fitness in patients with chronic stroke: a randomized, controlled trial.

BACKGROUND AND PURPOSE: Physical inactivity propagates disability after stroke through physical deconditioning and learned nonuse. We investigated whether treadmill aerobic training (T-AEX) is more effective than conventional rehabilitation to improve ambulatory function and cardiovascular fitness in patients with chronic stroke. METHODS: Sixty-one adults with chronic hemiparetic gait after ischemic stroke (>6 months) were randomized to 6 months (3x/week) progressive T-AEX or a reference rehabilitation program of stretching plus low-intensity walking (R-CONTROL). Peak exercise capacity (Vo2 peak), o2 consumption during submaximal effort walking (economy of gait), timed walks, Walking Impairment Questionnaire (WIQ), and Rivermead Mobility Index (RMI) were measured before and after 3 and 6 months of training. RESULTS: Twenty-five patients completed T-AEX and 20 completed R-CONTROL. Only T-AEX increased cardiovascular fitness (17% versus 3%, delta% T-AEX versus R-CONTROL, P<0.005). Group-by-time analyses revealed T-AEX improved ambulatory performance on 6-minute walks (30% versus 11%, P<0.02) and mobility function indexed by WIQ distance scores (56% versus 12%, P<0.05). In the T-AEX group, increasing training velocity predicted improved Vo2 peak (r=0.43, P<0.05), but not walking function. In contrast, increasing training session duration predicted improved 6-minute walk (r=0.41, P<0.05), but not fitness gains. CONCLUSIONS: T-AEX improves both functional mobility and cardiovascular fitness in patients with chronic stroke and is more effective than reference rehabilitation common to conventional care. Specific characteristics of training may determine the nature of exercise-mediated adaptations.

Timing, intensity, and duration of rehabilitation for hip fracture and stroke: report of a workshop at the National Center for Medical Rehabilitation Research.

This article summarizes the proceedings of an NIH workshop on timing, intensity, and duration of rehabilitation for acute stroke and hip fracture. Participants concentrated on methodological issues facing investigators and suggested priorities for future research in this area.

Hemiparetic muscle atrophy and increased intramuscular fat in stroke patients.

OBJECTIVE: To determine if skeletal muscle atrophy and greater fat deposition within the muscle are present in the hemiparetic limb of chronic (>6 mo) hemiparetic stroke patients. DESIGN: Cross-sectional study. SETTING: Hospital-based research center. PARTICIPANTS: Sixty patients (47 men, 13 women; mean age +/- standard deviation, 65+/-9 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients underwent a total body scan by dual-energy x-ray absorptiometry to determine percentage of body fat, total lean mass, fat mass, and lean mass of the paretic and nonaffected legs, thighs, and arms. Thirty patients received computed tomography (CT) scans of their midthigh to determine muscle area, subcutaneous fat, and low-density lean tissue, as a measure of fat within the muscle area, of the paretic and nonaffected midthigh. RESULTS: Patients were deconditioned (VO(2)peak: 1.2+/-0.3 L/min) with a percentage of body fat of 31.4%+/-9.8% and total lean mass of 51.4+/-9.1 kg. Lean mass of the paretic leg and thigh were 4% and 3% lower than the nonaffected leg (P<.001), but leg fat was not different. Arm lean mass of the paretic side was 7% lower than the nonaffected side, whereas arm fat was not different. CT studies showed that midthigh muscle area was 20% lower in the paretic limb than in the nonaffected leg (P<.001), midthigh subcutaneous fat was similar, and midthigh low-density lean tissue showed a trend to be 3% higher in the paretic leg (P=.06). The ratio of midthigh low-density lean tissue to muscle area was higher in the paretic leg (P<.001), which indicates a greater intramuscular fat relative to muscle area in the affected limb. CONCLUSIONS: Our results show hemiparetic skeletal muscle atrophy and more fat within the muscle, factors that may contribute to functional disability and increased cardiovascular disease risk in chronic hemiparetic stroke patients.

Microprocessor-based ambulatory activity monitoring in stroke patients.

PURPOSE: Recovery of ambulatory function after stroke is routinely assessed using standardized subject- or observer-rated instruments that do not directly measure ambulatory activities in the home-community setting. Accuracy of conventional pedometers in stroke patients is not established, limiting their application in mobility outcomes monitoring. This study investigates the accuracy and reliability of a mechanical pedometer versus microprocessor-based step activity monitoring (SAM) in gait-impaired hemiparetic stroke patients. METHODS: Accuracy and test-retest reliability of ankle-worn SAM and belt-worn pedometer were tested directly against hand tallied stride counts and cadence during a battery of timed walks in 16 chronic hemiparetic stroke patients. Patients performed replicate 1-min floor walks at self-selected and fastest comfortable paces, and two 6-min walks on separate days. RESULTS: SAM cadence and total stride counts are more accurate than pedometers during 1-min walks at self-selected (99 +/- 1 vs 87 +/- 11.3%, mean +/- SD, P < 0.01); fast pace (98 +/- 2.3% vs 85 +/- 15%, P < 0.01); and repeated 6-min walks performed on separate days (99 +/- 1% vs 89 +/- 12%, P < 0.01). Although SAM is highly reliable (r = 0.97, P < 0.0001) and accurate in all patients under every walking condition tested, the mechanical pedometer demonstrates this high level of accuracy in only half of stroke patients and has poor test-retest reliability (r = 0.64, P < 0.05). CONCLUSION: SAM, but not the conventional pedometer, provides accurate and reliable measures of cadence and total stride counts in hemiparetic stroke patients. Portable microprocessor-based gait monitoring offers potential to quantitatively measure home-community-based ambulatory activity levels in this population.