Association between walking 5000 step/day and fall incidence over six months in urban community-dwelling older people.

BACKGROUND: Walking is the most common population-wide campaign for health promotion in older people. However, the cutoff threshold for walking steps/day to identify the older people who are at risk of falling is not recommended. Therefore, the objectives were to investigate the association between all possible risk factors including physical performance, physical activity and fall incidence over the six-month in community-dwelling older people who had low-risk of falling and to identify walking threshold (steps/day) for reducing risk of fall. METHODS: The older people who aged ≥60 years and had free of falling for 1 year were invited to participate in this study. They lived in five communities in Bangkok Thailand. Demographics and physical performances were collected at baseline. Walking (step/day) and 24-h physical activity (PA) were monitored for 5 consecutive days by the Actical® accelerometer wrapped on non-dominant wrists. The Physical Activity Scale for the Elderly (PASE) questionnaire was used to record activities in the past 7 days by interview. A monthly calendar was used to record fall incidence over the 6 months. Unadjusted and adjusted hazard ratio (HR) with 95% confidence interval (CI) were analyzed using the Cox's proportional hazard regression. The Kaplan Meier curve illustrated the probability to survive from fall over the 6 months. RESULTS: Of 255, 33 older people (12.94%) reported first-fall incidence over the 6 months. Fall incidence density rate was 0.79 per 1000 person-day. Our findings showed that significant association between fall incidence and behavioral risk factors including PASE scores < 100 (HR = 3.53; 95% CI: 1.24-10.04), walking < 5000 steps/day (HR = 3.6; 95% CI: 1.76-7.31) and moderate to vigorous intensity of PA at < 60 min/week (HR = 3.66; 95% CI: 1.12-12.01). Fall incidence were related to the following risk factors: age (HR = 3.54; 95% CI: 1.37-9.11), took polypharmacy/antipsychotics (HR = 4.32; 95% CI: 2.12-8.79), presence of urinary incontinence (HR = 2.87; 95% CI: 1.45-5.68), low functional mobility by Timed Up and Go ≥13.5 s (HR = 6.43; 95% CI: 2.65-15.57). CONCLUSIONS: This study proposed walking ≥5000 steps/day as a cutoff threshold to recommend for reducing risk of falling in community-dwelling older people who had low-risk of falling.

Hormonal responses to graded-resistance, FES-assisted strength training in spinal cord-injured.

Functional electrical stimulation (FES) assisted resistance training has been effective in increasing muscular strength and endurance in spinal cord injured men and women in preparation for FES-assisted cycle programs and for FES-assisted standing and walking. Increases in blood pressure and a concomitant bradycardia suggestive of autonomic dysreflexia have been reported during FES-assisted resistance training. Self-induced autonomic dysreflexia in athletes who use wheelchairs suppressed the normal exercise induced serum testosterone increase. We, therefore, examined the changes in hematocrit and circulating levels of testosterone, sex hormone binding globulin (SHBG), cortisol, prolactin, norepinephrine and epinephrine during FES assisted resistance exercise in five high spinal cord injured men (SCI) and comparable maximal exercise in five able bodied controls (AB). Mean serum testosterone levels significantly increased with FES-assisted resistance training in SCI and maximal resistance exercise in AB with no significant change in hematocrit or SHBG. Prolactin, cortisol and epinephrine levels were unchanged while norepinephrine levels were significantly increased in SCI and AB. These findings suggest that there is no concern over inadequate physiological androgen response to an exercise stimulus in SCI. The data do not support the previous findings that elevated levels of norepinephrine in autonomic dysreflexia suppress testosterone response to exercise.

Efficacy of rowing, backward wheeling and isolated scapular retractor exercise as remedial strength activities for wheelchair users: application of electromyography.

Shoulder dysfunction due to regular wheelchair use is a common problem among people with spinal cord injuries. As a remedial measure, strengthening of the scapular retractor muscles has been suggested. Electromyographical analysis was utilized to examine scapular retraction muscle use during rowing, backward wheeling and a standardized scapular retraction exercise in seven people with spinal cord injuries and seven able bodied subjects. In addition, a pilot study using indwelling electrodes was completed to validate the use and placement of surface electrodes. Both rowing and the standardized scapular retraction exercise recruited higher levels of retractor involvement than backward wheeling. We suggest that rowing, because of its value as a cardiovascular exercise and high level of retractor recruitment, is an appropriate and effective means of remediating scapular retractor weakness.

Evidence of autonomic dysreflexia during functional electrical stimulation in individuals with spinal cord injuries.

The purpose of the investigation was to examine the safety and efficacy of functional electrical stimulation (FES)-assisted hydraulic resistance training in improving cardiovascular fitness in persons with spinal cord injuries. The cardiopulmonary responses of 10 high spinal cord injured (SCI) and five able bodied (AB) subjects were assessed during three bouts of FES-assisted leg extension exercise. The protocol involved three 30-minute tests: (1) unloaded leg extension, (2) hydraulically-resisted leg extension (loaded), and (3) a reproduction of the unloaded and loaded protocols to measure cardiac output (Q). Pre-measurements were made of body mass, mean limb weight, maximal force output and maximal oxygen uptake (incremental arm ergometry). Oxygen uptake (VO2), minute ventilation (Ve), respiratory exchange ratio (RER), heart rate (HR), blood pressure (BP) were recorded before, during and after tests. There was a significant difference in VO2 max between SCI and AB subjects. Cardiac output significantly increased between the loaded and unloaded tests. The significant increases from rest to unloaded and loaded exercise pointed to the potential value of adding resistance to a leg extension training regime. Heart rate and BP of the participants with SCI consistently demonstrated a response suggestive of autonomic dysreflexia. Upon stimulation an immediate increase in (predominantly systolic) BP was observed, followed by a fall in HR. On cessation of stimulation HR exhibited a substantial rebound effect and BP returned to normal levels. This response was highly reproducible and suggests caution be exercised in the use of FES for people with SCI with lesion levels above the major splanchnic outflow (T6).

Electrical stimulation-assisted rowing exercise in spinal cord injured people. A pilot study.

Recently a FES (functional electrical stimulation)-assisted rowing machine was developed to enhance cardiovascular training in people with spinal cord injuries. The machine was assessed in terms of its efficacy as a training tool. Six patients who were quadriplegic (C6-T1) and 2 who were paraplegic (T3-6) completed a series of three tests in succession: (1) leg stimulation only (quadriceps and hamstring groups)--'Stim', (2) arm row only--'Row' and (3) simultaneous row and stimulation--'R & S'. Measurements recorded included oxygen uptake (VO2), minute ventilation (Ve), respiratory exchange ratio (RER), heart rate (HR) and blood pressure (BP). In addition, 6 out of the 8 subjects took part in a qualitative assessment comprising a guided interview exploring the subject's perception of the machine and test. Significant increases in VO2 were demonstrated between the three tests with R & S producing mean steady-state values of 16.34 nm (+/- 0.74) ml/kg/min (83% of maximum). These values represented a 12% increase over Row alone. Of interest was the qualitative assessment which revealed that subjects perceived R & S to be easier than Row despite the higher levels of VO2 observed. The results suggest that the rowing machine represents a potentially valuable hybrid training device that may significantly reduce risk factors for cardiovascular disease and improve the quality of life of people with SCI.