This study examined the effects of six weeks strength training with elastic bands on different measures of strength manifestations, fatigue and functionality of multiple sclerosis (MS) patients. [Subjects] Sixteen MS patients (average age 44 years; range 33-56) with a diagnosis confirmed by a neurologist volunteered as subjects. They had mild to moderate disability and participated three times a week in a six-week elastic band strength training program. [Methods] Elastic band training progression was based on training volume using elastic bands of resistance of approximately 40% of a patient's previously measured maximal voluntary contraction. Outcome assessments included: maximal voluntary contraction with surface electromyography of the right and left legs, average and peak power with different submaximal loads of each leg, fatigue perception and functionality by the Timed Up-and-Go test. [Results] After the six-week strength training with elastic bands, average power with low load (98 N), peak power with very low load (49 N) and functionality had improved significantly. [Conclusion] A short and light training program using elastic bands can improve muscle function without injury and can be a good therapy for improving functionality of multiple sclerosis patients.

El objetivo del presente estudio fue comparar los valores de potencia y trabajo obtenidos en tiempo real mediante los sistemas BlueBrainTM y SmartCoachTM, durante ejercicio de fuerza en una prensa de piernas equipada con tecnología inercial flywheel, usando diferentes inercias (cargas). Se realizaron ocho series de siete repeticiones a intensidades variable y máxima, con dos minutos de descanso entre series, para cada inercia utilizada en el protocolo: 0.0125; 0.025; 0.0375; 0.05; 0.0625 y 0.075 kg*m², midiendo simultáneamente la potencia media concéntrica y el trabajo total (concéntrico-excéntrico) con ambos dispositivos. Los datos fueron analizados mediante un análisis de regresión lineal y un estudio de correlación. Se observó una correlación altamente significativa en los datos de potencia media entre ambos dispositivos en todas las inercias e intensidades evaluadas, tanto a nivel individual como global, (r=.968; Sig.(bilateral)=.000; R2=.937). De la misma forma, los datos de trabajo correlacionaron de forma muy significativa (r=.978; Sig.(bilateral)=.000; R2=.957). Las diferencias de registro entre ambos dispositivos oscilaron en un rango de 2.6-4.3 %. Dado el alto grado de significación en las correlaciones analizadas para potencia y trabajo, todo parece indicar que ambos dispositivos se muestran como instrumentos válidos y similares para estimar la potencia y el trabajo durante ejercicios de fuerza con tecnología inercial, siendo de gran ayuda para el seguimiento y control del entrenamiento usando esta tecnología.Abstract. The aim of this study was to compare real-time values of power and work obtained through BlueBrainTM and SmartCoachTM systems during flywheel leg press exercise using different inertias (loads). Eight sets of seven repetitions were performed at variable and maximum intensity for each inertia used (i.e. 0.0125; 0.025; 0.0375; 0.05; 0.0625 and 0.075 kg*m2), with 2 minutes recovery between sets. Average power during concentric actions and total work (concentric-eccentric) were measured simultaneously using both systems. Data were analysed using a linear regression analysis and correlation procedures. Strong significant correlations were observed in average power results between both data acquisition systems for all individual inertias and intensities evaluated, as well as for overall data (r=.968; Sig.(2-tailed)=.000; R2=.937). In addition, work values showed clear significant correlations (r=.978; Sig.(2-tailed)=.000; R2=.957). Differences between devices oscillated over a range of 2.6-4.3%. The strong correlations found in power and work values seem to indicate that both data acquisition systems are similar and valid to estimate power and work during resistance exercises employing flywheel inertial technology. Thus, both devices may represent a helpful tool to control and follow up training using flywheel technology.