Publications (21) View all
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Article: A prospective evaluation of balance, gait, and strength to predict falling in women with multiple sclerosis.
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ABSTRACT: To identify measures of balance, gait, and strength that predict falls in women with multiple sclerosis (MS). This prospective study followed participants for 1 year. University research laboratories. A convenience sample of women with MS (N=99). Not applicable. Balance was assessed with the limits of stability (LOS) test and the Sensory Organization Test. Peak force, torque, and power of knee flexors and extensors as well as hip abductors and adductors were also measured. Temporal-spatial parameters of gait were measured by an instrumented walkway system. For 1 year after baseline assessments, the participants reported their falls. Participants were then classified based on the number of reported falls for use in logistic regression models to predict either people with at least 1 fall or people with at least 2 falls (recurrent fallers). A total of 159 falls were reported by 48% of the participants. Expanded Disability Status Scale scores, leaning forward to the LOS, and standing sway within a visually referenced surround significantly predicted people with at least 1 fall as well as recurrent fallers. Stance-phase asymmetries and base-of-support width during gait, as well as the force and power produced during leg extension or flexion additionally predicted recurrent fallers. The models' overall predictive accuracy ranged from 69% to 85%. This prospective study confirmed the prevalence and multifactorial nature of falls in this MS sample. In addition to advancing disease status, impaired forward LOS and visually dependent sway (as well as gait asymmetries and leg flexor-extensor weakness for recurrent fallers) predict future falls in women with MS.Archives of physical medicine and rehabilitation 08/2011; 92(11):1840-6. · 2.18 Impact Factor -
Article: Transitional shifts in exercise behavior among women with multiple sclerosis.
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ABSTRACT: While physical activity is recommended to reduce symptomology associated with multiple sclerosis (MS) little has been done to explore the potential usefulness of theoretical models of exercise behavior change in individuals with MS. Based on the success of the transtheoretical model of exercise behavior change (TTM) in the general population and early promising results in those with MS, the TTM was tested in a sample of women with MS over a 1-year period, to examine its usefulness and the effect of TTM constructs on MS-related symptoms. This was a longitudinal study conducted over a 1-year period. Ambulatory women (N=86) with MS completed questionnaires assessing exercise behavior, TTM constructs, MS-related quality of life, pain, and fatigue at baseline and after 1 year. After categorization into transitional shift patterns reflecting naturally occurring exercise behavior change over the year, a series of mixed-design analyses of variance were conducted to examine TTM predictions and the relationship of the transitional shift patterns to MS-related quality of life, pain, and fatigue. Significant interactions between transitional shift patterns and time (P < .05) indicated that changes in behavioral and cognitive processes of change and in self-efficacy were consistent with TTM predictions. Significant differences (P < .05) between the transitional shift groups in pain and fatigue in expected directions were also found. Results supported the TTM proposed relationships, indicating the model's potential for motivating individuals with MS to increase their physical activity. Findings also support the notion that physical activity is useful in reducing MS-related symptoms and that lifestyle types of physical activity may be as useful as structured exercise in bringing about these outcomes.Disability and Health Journal 10/2009; 2(4):216-23. · 0.98 Impact Factor -
Article: Alcohol alters whole body composition, inhibits bone formation, and increases bone marrow adiposity in rats.
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ABSTRACT: Chronic alcohol abuse is a risk factor for osteoporosis and sarcopenia, but the long-term effects of alcohol on the immature musculoskeletal system are less clear. The present investigation in growing rats was designed to determine the effects of alcohol consumption on body composition, muscle mass, and bone mass, architecture, and turnover. Few studies have focused on the long-term effects of drinking on bone and muscle during skeletal maturation. Alcohol was included in the diet of 4-week-old male Sprague-Dawley rats (35% caloric intake) for 3 months. The controls were fed an isocaloric alcohol-free liquid diet ad libitum. A second study was performed in which the controls were pair-fed to the alcohol-fed animals. Compared to ad libitum-fed age-matched controls, alcohol-fed rats weighed less and had lower lean mass, fat mass, and percent body fat. In addition, they had lower slow- and fast-twitch muscle mass, lower total body bone mineral content and bone mineral density, and lower cancellous bone volume in the lumbar vertebra and proximal tibia. The effects of alcohol consumption on body composition were reduced when compared to the pair-fed control diet, indicating that caloric restriction was a comorbidity factor. In contrast, the effects of alcohol to decrease bone formation and serum leptin and IGF-I levels and to increase bone marrow adiposity appeared independent of caloric restriction. The skeletal abnormalities in growing alcohol-fed rats were due to a combination of effects specific to alcohol consumption and alcohol-induced caloric restriction.Osteoporosis International 03/2009; 20(9):1529-38. · 4.58 Impact Factor -
Article: Tai chi and postural stability in patients with Parkinson's disease.
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ABSTRACT: Patients with Parkinson's disease have substantially impaired balance, leading to diminished functional ability and an increased risk of falling. Although exercise is routinely encouraged by health care providers, few programs have been proven effective. We conducted a randomized, controlled trial to determine whether a tailored tai chi program could improve postural control in patients with idiopathic Parkinson's disease. We randomly assigned 195 patients with stage 1 to 4 disease on the Hoehn and Yahr staging scale (which ranges from 1 to 5, with higher stages indicating more severe disease) to one of three groups: tai chi, resistance training, or stretching. The patients participated in 60-minute exercise sessions twice weekly for 24 weeks. The primary outcomes were changes from baseline in the limits-of-stability test (maximum excursion and directional control; range, 0 to 100%). Secondary outcomes included measures of gait and strength, scores on functional-reach and timed up-and-go tests, motor scores on the Unified Parkinson's Disease Rating Scale, and number of falls. The tai chi group performed consistently better than the resistance-training and stretching groups in maximum excursion (between-group difference in the change from baseline, 5.55 percentage points; 95% confidence interval [CI], 1.12 to 9.97; and 11.98 percentage points; 95% CI, 7.21 to 16.74, respectively) and in directional control (10.45 percentage points; 95% CI, 3.89 to 17.00; and 11.38 percentage points; 95% CI, 5.50 to 17.27, respectively). The tai chi group also performed better than the stretching group in all secondary outcomes and outperformed the resistance-training group in stride length and functional reach. Tai chi lowered the incidence of falls as compared with stretching but not as compared with resistance training. The effects of tai chi training were maintained at 3 months after the intervention. No serious adverse events were observed. Tai chi training appears to reduce balance impairments in patients with mild-to-moderate Parkinson's disease, with additional benefits of improved functional capacity and reduced falls. (Funded by the National Institute of Neurological Disorders and Stroke; ClinicalTrials.gov number, NCT00611481.).New England Journal of Medicine 02/2012; 366(6):511-9. · 53.30 Impact Factor -
Article: Whole-body vibration slows the acquisition of fat in mature female rats.
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ABSTRACT: To evaluate the effects of whole-body vibration on fat, bone, leptin and muscle mass. Thirty 7-month-old female 344 Fischer rats were randomized by weight into three groups (baseline, vibration or control; n=8-10 per group). Rats in the vibration group were placed inside individual compartments attached to a Pneu-Vibe vibration platform (Pneumex, Sandpoint, ID, USA) and vibrated at 30-50 Hz (6 mm peak to peak) for 30 min per day, 5 days per week, for 12 weeks. The vibration intervention consisted of six 5-min cycles with a 1-min break between cycles. There were significant body composition differences between the whole-body vibration and the control group. The whole-body vibration group weighed approximately 10% less (mean+/-s.d.; 207+/-10 vs 222+/-15 g, P<0.03) and had less body fat (20.8+/-3.8 vs 26.8+/-5.9 g, P<0.05), a lower percentage of body fat (10.2+/-1.7 vs 12+/-2.0%, P<0.05), and lower serum leptin levels (1.06+/-0.45 vs 2.27+/-0.57 ng ml(-1), P<0.01) than the age-matched controls. No differences were observed for total lean mass, bone mineral content (BMC), bone mineral density (BMD), insulin-like growth factor-I (IGF-I) or soleus (SOL) and extensor digitorum longus (EDL) mass or function. Regional high-resolution dual-energy X-ray absoptiometry scans of the lumbar spine (L1-4) revealed that the whole-body vibration group had significantly greater BMC (0.33+/-0.05 vs 0.26+/-0.03 g, P<0.01) and BMD (0.21+/-0.01 vs 0.19+/-0.01 g cm(-2), P<0.01) than the control group. No differences between the groups were observed in the amount of food consumed. These findings show that whole-body vibration reduced body fat accumulation and serum leptin without affecting whole body BMC, BMD or lean mass. However, the increase in vertebral BMC and BMD suggests that vibration may have resulted in local increases in bone mass and density. Also, whole-body vibration did not affect muscle function or food consumption.International journal of obesity (2005) 08/2008; 32(9):1348-54. · 4.34 Impact Factor
