RESUMEN
OBJECTIVE: To identify whether a relationship exists between stretch and activity of the calf muscles during the stance phase of gait in patients with upper motor neuron syndrome (UMNS), while taking into account the physiologic phase shift between these entities. DESIGN: Survey. SETTING: Ambulatory care and general community. PARTICIPANTS: Patients with UMNS (n=15; 9 patients with stroke, 6 patients with hereditary spastic paraparesis) with premature calf muscle activity during the stance phase of gait and healthy controls (n=13). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Timing of optimal association (phase shift) between the lengthening velocity of the gastrocnemius muscle and its electromyographic activity as revealed by cross-correlation analyses. RESULTS: Although premature calf muscle activity was evident in the patient groups, the phase shift between calf muscle stretch and its activity did not correspond with the monosynaptic stretch reflex latency (40- to 80-ms time window). However, there was a main effect of group on the phase shifts (F(3,33)=3.23, P=.035). Post hoc analysis revealed that in the paretic leg of stroke patients, the electromyographic activity preceded the lengthening velocity by 9 ± 54ms, whereas in the control group, the electromyographic activity followed the pattern of the muscle-lengthening velocity with a delay of 61 ± 54ms (P=.029). CONCLUSIONS: Short-latency stretch reflexes do not significantly contribute to premature calf muscle activity in the stance phase of (spastic) gait. This notion questions the validity of the clinical assessment of hyperreflexia and clonus of the calf as a predictor of calf muscle spasticity during gait.
Asunto(s)
Marcha/fisiología , Extremidad Inferior , Enfermedad de la Neurona Motora/rehabilitación , Espasticidad Muscular/rehabilitación , Reflejo de Estiramiento/fisiología , Adulto , Femenino , Humanos , Persona de Mediana Edad , Enfermedad de la Neurona Motora/complicaciones , Espasticidad Muscular/etiología , Caminata/fisiologíaRESUMEN
Although early sitting balance is a well-known predictor of functional outcome after stroke, it is still unknown which aspects of normal upright sitting balance are most sensitive to subsequent recovery. This study used an adjustable chair mounted on a force platform to assess the recovery of quiet-sitting balance in 16 patients with a first supratentorial stroke during their inpatient rehabilitation. The patients underwent three posturographic assessments at 6-week intervals from the moment of their admission, on average 5.6 weeks after stroke. Each quiet-sitting balance assessment consisted of two series of four 30-s test conditions: sitting with eyes open and closed, on both a stable and unstable (air cushion) surface. The RMS of the center-of-pressure (COP) velocities was used as the primary measure of lateral and anteroposterior balance control. It was found that, compared to 10 healthy elderly, lateral balance was more affected by stroke than balance in the anteroposterior direction, especially during visual deprivation, and most sensitive to subsequent functional changes induced by spontaneous recovery or rehabilitation. Furthermore, lateral balance control showed the strongest association with the Berg Balance Scale as a clinical measure of balance capacity. Hence, (lateral) trunk control seems to be a primary target for rehabilitation. Since an unstable support was necessary to obtain significant effects of stroke, recovery and visual deprivation, it may be important to use an unstable support during sitting balance training as well.
Asunto(s)
Accidente Cerebrovascular/fisiopatología , Anciano , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Equilibrio Postural , Desempeño Psicomotor/fisiología , Tiempo de Reacción , Umbral Sensorial , Rehabilitación de Accidente Cerebrovascular , Análisis y Desempeño de Tareas , Percepción Visual/fisiologíaRESUMEN
BACKGROUND AND PURPOSE: The long-term effects of 6-weeks whole-body vibration, as a novel method of somatosensory stimulation, on postural control and activities of daily living were compared with those of 6 weeks of exercise therapy on music of the same intensity in the postacute phase of stroke. METHODS: Fifty-three patients with moderate to severe functional disabilities were randomized within 6 weeks poststroke and within 3 days after admission to a rehabilitation center to either whole-body vibration or exercise therapy on music in addition to a regular inpatient rehabilitation program. The whole-body vibration group received 4x45-second stimulation on the Galileo 900 (30-Hz frontal plane oscillations of 3-mm amplitude) for 5 days per week during 6 weeks. The exercise therapy on music group received the same amount of exercise therapy on music. Outcome variables included the Berg Balance Scale, Trunk Control Test, Rivermead Mobility Index, Barthel Index, Functional Ambulation Categories, Motricity Index, and somatosensory threshold at 0, 6, and 12 weeks follow up. RESULTS: At baseline, both groups were comparable in terms of prognostic factors and outcome measures. Both at 6 and 12 weeks follow up, no clinically relevant or statistical differences in outcome were observed between the groups. No side effects were reported. CONCLUSIONS: Daily sessions of whole-body vibration during 6 weeks are not more effective in terms of recovery of balance and activities of daily living than the same amount of exercise therapy on music in the postacute phase of stroke.