Effect of treadmill gait on bone markers and bone mineral density of quadriplegic subjects

Quadriplegic subjects present extensive muscle mass paralysis which is responsible for the dramatic decrease in bone mass, increasing the risk of bone fractures. There has been much effort to find an efficient treatment to prevent or reverse this significant bone loss. We used 21 male subjects, mean age 31.95 ± 8.01 years, with chronic quadriplegia, between C4 and C8, to evaluate the effect of treadmill gait training using neuromuscular electrical stimulation, with 30-50% weight relief, on bone mass, comparing individual dual-energy X-ray absorptiometry responses and biochemical markers of bone metabolism. Subjects were divided into gait (N = 11) and control (N = 10) groups. The gait group underwent gait training for 6 months, twice a week, for 20 min, while the control group did not perform gait. Bone mineral density (BMD) of lumbar spine, femoral neck, trochanteric area, and total femur, and biochemical markers (osteocalcin, bone alkaline phosphatase, pyridinoline, and deoxypyridinoline) were measured at the beginning of the study and 6 months later. In the gait group, 81.8% of the subjects presented a significant increase in bone formation and 66.7% also presented a significant decrease of bone resorption markers, whereas 30% of the controls did not present any change in markers and 20% presented an increase in bone formation. Marker results did not always agree with BMD data. Indeed, many individuals with increased bone formation presented a decrease in BMD. Most individuals in the gait group presented an increase in bone formation markers and a decrease in bone resorption markers, suggesting that gait training, even with 30-50% body weight support, was efficient in improving the bone mass of chronic quadriplegics.1357136

Contribuição da aplicação do ultrassom de baixa potência na prevenção de osteopenia em tíbias de ratos sob ausência de carga

Este trabalho objetivou verificar se o ultrassom de baixa potência (US) previne a ocorrência de osteopenia em tíbias de ratos sob ausência de carga. Foram utilizados 45 Rattus novergicus albinus, Wistar adultos, machos, distribuídos em cinco grupos iguais: C - animais-controle livres em gaiolas por 21 dias; S - animais suspensos pela cauda por 21 dias; ST - suspensos pela cauda por 21 dias e concomitantemente tratados com US; S→C - suspensos por 21 dias e depois permanecendo livres em gaiolas por mais 21 dias; S→CT - suspensos por 21 dias e depois permanecendo livres em gaiolas por mais 21 dias e concomitantemente tratados com US. O tratamento foi realizado com US de 1,5MHz, ciclo de trabalho 1:4, 30mW/cm², na tíbia direita, por 15 sessões de 20 minutos cada, cinco sessões por semana. Ainda vivos, os animais foram submetidos a exame de densitometria óssea para verificação da densidade mineral óssea (DMO) e do conteúdo mineral ósseo (CMO). Após a eutanásia dos animais, as tíbias foram desarticuladas, dissecadas e submetidas a ensaio mecânico destrutivo para análise da força máxima (Fmáx) e da rigidez (R). Foram avaliados também o comprimento (L) e o diâmetro (D) no ponto médio da tíbia. O grupo S apresentou valores de DMO, CMO, Fmáx, R, L e D menores em relação ao grupo C, demonstrando que a suspensão pela cauda é prejudicial a estas variáveis. O tratamento dos animais suspensos com o US, grupo ST, elevou os valores de CMO e DMO em relação aos do grupo S, igualando-os aos do grupo C. A Fmáx, R e L do grupo ST aumentou em relação ao grupo S e também em relação ao grupo C (p0,05). Os resultados obtidos neste estudo permitem concluir que o US de baixa potência contribuiu na prevenção e reversão da ocorrência da osteopenia nos animais submetidos à suspensão pela cauda, demonstrando que a ausência do estímulo mecânico causada pela impossibilidade da deambulação pode ser minimizada pela ação mecânica deste.This work intended to verify if the low power ultrasound (US) prevents the occurrence of osteopenia on the tibia of rats under the absence of load. 45 adult male Wistar Rattus novergicus albinus were used, separated in five equal groups: C - control free animals in cages for 21 days; S - animals suspended by the tail for 21 days; ST - animals suspended by the tail for 21 days and concurrently treated with US; S→C - animals suspended for 21 days and then free in cages for another 21 days; S→CT - animals suspended for 21 days and then free in cages for another 21 days and concurrently treated with US. The treatment was performed with US with 1.5 MHz, work cycle 1:4, 30 mW/cm², on tibia, for 15 sessions of 20 minutes each, 5 sessions per week. While still alive, the animals underwent bone densitometry examination to verify the Bone Mineral Density (BMD) and the Bone Mineral Content (BMC). After the euthanasia of the animals, the tibias were disjointed, dissected and underwent destructive mechanical testing for the analysis of the maximum force (Fmax) and Rigidity (R). The length (L) and the diameter (D) of the middle point of the tibia were also measured. In group S, BMD, BMC, Fmax, R, L and D were smaller than in group C, demonstrating that the suspension by the tail is detrimental to these variables. The treatment of the suspended animals with the US, in group ST, increased the BMD and BMC compared to group S, leveling them to group C. The Fmax, R and L of group ST increased compared to group S and compared to group C as well (p0.05). The results obtained in this study lead to the conclusion that the low power US contributes to the prevention of the occurrence of osteopenia on animals under suspension by the tail, showing that the absence of the mechanical stimulation caused by the impossibility of deambulation can be minimized by its action.Universidade Estadual PaulistaUniversidade Estadual Paulist

Response of the arterial blood pressure of quadriplegic patients to treadmill gait training

Blood pressure pattern was analyzed in 12 complete quadriplegics with chronic lesions after three months of treadmill gait training. Before training, blood pressure values were obtained at rest, during treadmill walking and during the recovery phase. Gait training was performed for 20 min twice a week for three months. Treadmill gait was achieved using neuromuscular electrical stimulation, assisted by partial body weight relief (30-50%). After training, blood pressure was evaluated at rest, during gait and during recovery phase. Before and after training, mean systolic blood pressures and heart rates increased significantly during gait compared to rest (94.16 ± 5.15 to 105 ± 5.22 mmHg and 74.27 ± 10.09 to 106.23 ± 17.31 bpm, respectively), and blood pressure decreased significantly in the recovery phase (86.66 ± 9.84 and 57.5 ± 8.66 mmHg, respectively). After three months of training, systolic blood pressure became higher at rest (94.16 ± 5.15 mmHg before training and 100 ± 8.52 mmHg after training; P < 0.05) and during gait exercise (105 ± 5.22 mmHg before and 110 ± 7.38 mmHg after training; P < 0.05) when compared to the initial values, with no changes in heart rate. No changes occurred in blood pressure during the recovery phase, with the lower values being maintained. A drop in systolic pressure from 105 ± 5.22 to 86.66 ± 9.84 mmHg before training and from 110 ± 7.38 to 90 ± 7.38 mmHg after training was noticed immediately after exercise, thus resulting in hypotensive symptoms when chronic quadriplegics reach the sitting position from the upright position

Investigation Of Osteometabolic And Cardio-respiratory Changes Occurring After Gait Training Under Neuromuscular Electric Stimulation In Quadriplegic Patients [investigação Das Alterações Osteo- Metabólicas E Cardio-respiratórias Ocorridas Após O Treinamento De Marcha Sob Estimulação Elétrica Neuromuscular Em Pacientes Tetraplégicos]

This study was aimed to evaluate the effects of gait training with neuromuscular electric stimulation (NMES) on skeletal and cardio-respiratory systems of full quadriplegic patients (C4-C8). Aerobic power (VO2), carbon dioxide production (VCO2), minute ventilation (VE), heart rate (HR), blood pressure (BP), energy consumption, bone markers analysis (osteocalcin, bone alkaline phosphatase, pyridinoline, and deoxypyridinoline) and bone densitometry (DEXA) of the femoral neck and total femur were performed at baseline and six months later. Eleven patients walked on ergometric wake, with NMES and discharge of 60 - 70% of body weight, during six months, twice a week, 20 minutes daily. Ten patients did not perform the gait. Within the gait group, 81.8% showed significant increases of formation markers, of which 72.7% also presented with reduced bone resorption. Within the control group, 20% showed increased bone formation. DEXA results were, in general, opposite to those of bone markers. Cardio-respiratory tests showed a significant increase for VO2 l/min (36%), VCO2 (42.97%), VE (30.48%), SBP mmHg (4.8%) and energy consumption kcal/min (37.68%). In the control group, only VO2 l/min showed a significant increase (26.29%). Gait training with NMES was more efficient in increasing bone formation rates and aerobic power in quadriplegic patients.143141147Whiteneck, G.G., Charlifue, S.W., Frankel, H.L., Fraser, M.H., Gardner, B.P., Gerhart, K.A., Krishnan, K.R., Short, D.J., Mortality, morbidity, and psychosocial outcomes of persons spinal cord injured more than 20 years ago (1992) Paraplegia, 30, pp. 617-630De Barros Filho, T.E., De Oliveira, R.P., Tsanaclis, A.M., De Barros, E.M., Cristante, A.F., Palma, R.M., An experimental model for the transplantation of fetal central nervous system cells to the injured spinal cord in rats (2002) Rev Hosp Clin Fac Med São Paulo, 57, pp. 256-264Garland, D.E., Stewart, C.A., Adkins, R.H., Hu, S.S., Rosen, C., Liotta, F.J., Weinstein, D.A., Osteoporosis after spinal cord injury (1992) J Orthop Res, 10, pp. 371-378Mohr, T., Podenphant, J., Biering-Sorensen, F., Galbo, H., Thamsborg, G., Kjær, M., Increased bone mineral density after prolonged electrically induced cycle training of paralyzed limbs in spinal cord injured man (1997) Calcif Tissue Int, 61, pp. 22-25Figoni, S.F., Exercise responses and quadriplegia (1993) Med Sci Sports Exerc, 25, pp. 433-441Faghri, P.D., Glaser, R.M., Figoni, S.F., Functional electrical stimulation leg cycle ergometer exercise: Training effects on cardiorespiratory responses of spinal cord injured subjects at rest and during submaximal exercise (1992) Arch Phys Med Rehabil, 73, pp. 1085-1093Hannon, R., Blumsohn, A., Naylor, K., Eastell, R., Response of biochemical markers of bone turnover to hormone replacement therapy: Impact of biological variability (1998) J Bone Miner Res, 13, pp. 1124-1133Lekamwasam, S., Lenora, R.S., Effect of leg rotation on hip bone mineral density measurements (2003) J Clin Densitom, 6, pp. 331-336Bloomfield, S.A., Mysiw, W.J., Jackson, R.D., Bone mass and endocrine adaptations to training in spinal cord injured individuals (1996) Bone, 19, pp. 61-68Dawson-Hughes, B., Pharmacologic treatment of postmenopausal osteoporosis (1999) An Official Publication of the American Society for Bone and Mineral Research. Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism. 4th Ed., pp. 283-288. , MJ Favus, editor. Philadelphia: Lippincott-Raven PublishersGoss, F.L., Mcdermott, A., Robertson, R.J., Changes in peak oxygen uptake following computerized functional electrical stimulation in the spinal cord injured (1992) Res Q Exerc Sport, 63, pp. 76-79Mohr, T., Andersen, J.L., Biering-Sorensen, F., Galbo, H., Bangsbo, J., Wagner, A., Kjær, M., Long-term adaptation to electrically induced cycle training in severe spinal cord injured individuals (1997) Spinal Cord, 35, pp. 1-16Dela, F., Mohr, T., Jensen, C.M.R., Haahr, H.L., Secher, N.H., Biering-Sorensen, F., Kjær, Cardiovascular control during exercise: Insights from spinal cord-injured humans (2003) Circulation, 107, pp. 2127-2133Janssen, T.W.J., Dallmeijer, A.J., Veeger, D., Van Der Woude, L.H.V., Normative values and determinants of physical capacity in individuals with spinal cord injury (2002) J Rehabil Res Dev, 39, pp. 29-39Blair, S.N., Kolh, H.W., Pattenbarger, R.S., Clark Jr., D.G., Cooper, K.H., Gibbons, L.W., Physical fitness and all causes of mortality: A prospective study of healthy men and women (1989) J Amer Med Assoc, 262, pp. 2395-240

Effect of treadmill gait on bone markers and bone mineral density of quadriplegic subjects

Quadriplegic subjects present extensive muscle mass paralysis which is responsible for the dramatic decrease in bone mass, increasing the risk of bone fractures. There has been much effort to find an efficient treatment to prevent or reverse this significant bone loss. We used 21 male subjects, mean age 31.95 ± 8.01 years, with chronic quadriplegia, between C4 and C8, to evaluate the effect of treadmill gait training using neuromuscular electrical stimulation, with 30-50% weight relief, on bone mass, comparing individual dual-energy X-ray absorptiometry responses and biochemical markers of bone metabolism. Subjects were divided into gait (N = 11) and control (N = 10) groups. The gait group underwent gait training for 6 months, twice a week, for 20 min, while the control group did not perform gait. Bone mineral density (BMD) of lumbar spine, femoral neck, trochanteric area, and total femur, and biochemical markers (osteocalcin, bone alkaline phosphatase, pyridinoline, and deoxypyridinoline) were measured at the beginning of the study and 6 months later. In the gait group, 81.8% of the subjects presented a significant increase in bone formation and 66.7% also presented a significant decrease of bone resorption markers, whereas 30% of the controls did not present any change in markers and 20% presented an increase in bone formation. Marker results did not always agree with BMD data. Indeed, many individuals with increased bone formation presented a decrease in BMD. Most individuals in the gait group presented an increase in bone formation markers and a decrease in bone resorption markers, suggesting that gait training, even with 30-50% body weight support, was efficient in improving the bone mass of chronic quadriplegics