Tiempos de activación muscular frente a una desestabilización en pacientes con enfermedad de Parkinson en etapas iniciales / Muscle activation times facing to a perturbation in patients with early-stage Parkinson's disease

Objetivos: La enfermedad de Parkinson (EP) genera alta incidencia de caídas, sin embargo, existe poca evidencia de inestabilidades en etapas iniciales. Esta investigación buscó comparar los tiempos de activación muscular en pacientes con EP inicial frente a una alteración postural vs. un grupo control. Materiales y métodos: Se evaluó la actividad electromiográfica (EMG) de 10 pacientes con EP (61,3 ± 3,8 años) en etapas iniciales y grupo control de 10 adultos (62,2 ±3,0 años). Los participantes fueron tratados mediante una alteración de la superficie, la cual generó una respuesta de estabilización. La prueba se realizó en 2condiciones: ojos abiertos (OA) vs. ojos cerrados (OC). Se analizó el tiempo de activación de músculos del tronco (erector espinal) y extremidad inferior (sóleo, tibial anterior, peroneo lateral largo, recto femoral, bíceps femoral, glúteo medio y aductor mayor) usando EMG de superficie. Resultados: El grupo con EP mostró tiempos de respuestas más rápidas en comparación con l grupo control en el músculo sóleo en OC (p=0,04). Este mismo músculo mostró diferencias al comparar OA vs. OC solo en el grupo con EP (p=0,04), mostrando un menor tiempo de respuesta en la condición OC. Al comparar el músculo erector espinal el grupo con EP mostró tiempos de respuesta más lentos en la condición de OA (p=0,02) y OC (p=0,04) con relación al grupo control. Conclusiones: Los tiempos de activación muscular muestran que las personas con EP responden con un retraso en la activación en la musculatura del tronco, mientras que a nivel distal responden más rápido que los sujetos controles. En las etapas tempranas las respuestas más lentas a nivel de tronco podrían explicar el inicio de las alteraciones del equilibrio en estos pacientes.(AU)

Objectives: Parkinson's disease (PD) generates a high incidence of falls, however, there is little evidence of instabilities in the initial stages. This investigation sought to compare the muscle activation times in patients with initial PD against a postural disturbance vs. a control group. Materials and methods: The electromyographic activity (EMG) of 10 patients with PD in early stages (61.3 ±3.8 years) and a control group of 10 adults (62.2 ±3.0 year) was evaluated. The participants were subjected to a surface disturbance, which generated a stabilization response. The test was performed under 2conditions: eyes open (OA) v/s eyes closed (OC). Trunk (spinal erector) and lower extremity (soleus, tibialis anterior, femoral biceps, femoral rectus, adductor magnus, gluteus medius) muscle activation time was analyzed using surface EMG. Results: The PD group showed faster response times compared to the control group in the soleus muscle in OC (P=.04). This same muscle showed differences when comparing OA vs. OC only in the PD group (P=.04), showing a shorter response time in the OC condition. When comparing the spinal erector muscle, the PD group showed slower response times in the OA (P=.02) and OC (P=.04) conditions compared to the control group. Conclusions: Muscle activation times show that people with PD respond slower in the trunk muscles, while activation times decrease at the distal level. In the early stages, the slower responses at the trunk level could explain the onset of instability postural in these patients.(AU)

[Muscle activation times facing to a perturbation in patients with early-stage Parkinson's disease]. / Tiempos de activación muscular frente a una desestabilización en pacientes con enfermedad de Parkinson en etapas iniciales.

OBJECTIVES: Parkinson's disease (PD) generates a high incidence of falls, however, there is little evidence of instabilities in the initial stages. This investigation sought to compare the muscle activation times in patients with initial PD against a postural disturbance vs. a control group. MATERIALS AND METHODS: The electromyographic activity (EMG) of 10 patients with PD in early stages (61.3 ±3.8 years) and a control group of 10 adults (62.2 ±3.0 year) was evaluated. The participants were subjected to a surface disturbance, which generated a stabilization response. The test was performed under 2conditions: eyes open (OA) v/s eyes closed (OC). Trunk (spinal erector) and lower extremity (soleus, tibialis anterior, femoral biceps, femoral rectus, adductor magnus, gluteus medius) muscle activation time was analyzed using surface EMG. RESULTS: The PD group showed faster response times compared to the control group in the soleus muscle in OC (P=.04). This same muscle showed differences when comparing OA vs. OC only in the PD group (P=.04), showing a shorter response time in the OC condition. When comparing the spinal erector muscle, the PD group showed slower response times in the OA (P=.02) and OC (P=.04) conditions compared to the control group. CONCLUSIONS: Muscle activation times show that people with PD respond slower in the trunk muscles, while activation times decrease at the distal level. In the early stages, the slower responses at the trunk level could explain the onset of instability postural in these patients.