Speed related changes in muscle activity from normal to very slow walking speeds

Abstract

Speed related changes in muscle activity from normal to very slow walking speeds den Otter, Rob; Mulder, T.; Duysens, J. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. AbstractThe study of neuromuscular activity at very slow walking speeds may lead to a better understanding of the mechanisms underlying speed regulation during walking, and may aid the interpretation of gait data in patients who walk slowly. Extreme reductions in walking speed will cause changes in locomotor task demands that may eventually result in modifications of the patterning of muscle activity that underlies walking. The aim of the present study was to investigate patterns of lower limb muscle activity during very slow walking (< 0.28 m s −1 ), and to study the neuromuscular gain functions that reflect the phase dependent effects of walking speed on electromyographic (EMG) amplitude. Nine healthy young adults walked at seven different walking speeds (1.39, 0.83, 0.28, 0.22, 0.17, 0.11, and 0.06 m s −1 ) while EMG was recorded from eight lower extremity muscles. Results showed that the phasing of muscle activity remained relatively stable over walking speeds despite substantial changes in its amplitude. However, between 1.39 and 0.28 m s −1 , epochs of Rectus femoris, Biceps femoris and Tibialis anterior activities were found that were typical for specific speed ranges. When walking speed decreased further to almost standing still (0.06 m s −1 ), negative gain values were found in Peroneus longus during midstance and Rectus femoris in late swing, indicating the emergence of new bursts of activity with decreasing walking speed. It is proposed that these extra activities may be attributed to increased demands on postural stability, and the altered dynamics of the swinging limb at very slow speeds.

Fascicle Length Change of the Human Tibialis Anterior and Vastus Lateralis During Walking

“…This study confirms, as others have shown, that the TA and the VL are active during the expected phases of the gait cycle. 7,8,31 The change in fascicle length provides insight into the dynamics of muscle function and inferences can be made concerning the interaction between muscle fascicle and tendon length change during different phases of the gait cycle.…”

Análisis de la marcha: evaluación de un exoesqueleto aplicado a la marcha asistida

“…Numerosos autores han estudiado la influencia de la velocidad en los parámetros espaciotemporales y cinemáticos, determinando cuáles son los cambios que se producen en la marcha humana durante una velocidad lenta (Beauchet et al, 2009;Bejek et al, 2006;Chiu, Wu, & Chang, 2013;Chung, & Wang, 2010;Den Otter, Geurts, Mulder, & Duysens, 2004;Hirasaki, Moore, Raphan, & Cohen., 1999;Jordan, Challis, & Newell, 2007;Kang, & Dingwell, 2007;Kavanagh, 2009;Nymark et al, 2005;Orendurff et al, 2004;Pépin et al, 2003a;Pépin et al, 2003b;Shemmell, Johansson, Portra, Gottlieb, Thomas, & Corcos, 2007;Swinnen et al, 2013;Tanawongsuwan, & Bobick, 2003;Tesio et al, 1998;Thomas, De Vito, & Macaluso, 2007;Yoon, Park, & Damiano, 2012). La cadencia y longitud de paso o longitud de zancada, directamente relacionados con la velocidad, disminuyen de forma paralela a la velocidad (Bejek et al, 2006;Kirtley, 2006;Riley et al, 2001;Shemmell et al, 2007;Tanawongsuwan, & Bobick, 2003), mientras que el ancho de paso se incrementa para dar mayor base de sustentación (Ordendurff et al, 2004).…”

“…Poniendo de manifiesto los cambios en el patrón de la marcha como consecuencia de una disminución de la velocidad, resulta importante el estudio de los patrones de la marcha con sujetos sanos y la creación de bases de datos a velocidades lentas con el objetivo de poder disociar las modificaciones del patrón normal relativas a las patologías neuromusculoesqueléticas de las adaptaciones producidas por la velocidad (Den Otter et al, 2004;Nymark et al, 2005). Además, estas bases de datos debieran estar diseñadas para cada una de las velocidades elegidas en cada una de las patologías.…”

Identification of connectivity in human motor control: exciting the afferent pathways

“…Previous studies did not show a clear effect of walking speed on EMG-EMG (Hansen et al, 2005;den Otter et al, 2004) or EEG-EMG (Petersen et al, 2012) coherence. In accordance with these studies we also observed no influence of walking speed on the coherence variables.…”

“…TA is active during the complete swing phase, which lasts from approximately 60% − 100% of the gait cycle (where 0 and 100% indicate heel strike of the concerned leg). As the timing of this muscle's burst is similar across the walking speeds used in this study (den Otter et al, 2004), we selected for every step the segment between 60% and 100% of the gait cycle. Although the TA activity extends into the stance phase, we did not use this data to exclude any possible heel strike artefacts from the analysis (Petersen et al, 2010).…”