Contributions of the individual ankle plantar flexors to support, forward progression and swing initiation during walking

Neptune, Richard R.; Kautz, Steven A.; Zajac, Felix E.

doi:10.1016/s0021-9290(01)00105-1

Cited by 913 publications

(870 citation statements)

References 35 publications

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“…Muscle contributions to support and progression for our full-strength simulations generally agreed with previous studies (Kepple et al, 1997;Neptune et al, 2001;Anderson and Pandy, 2003;Neptune et al, 2004;Liu et al, 2006;Liu et al, 2008). Previous work by Neptune et al (Neptune et al, 2004) found that the rectus femoris works to accelerate the body forward in late stance.…”

Section: Discussionsupporting

confidence: 89%

“…In particular, lower extremity muscles perform two main tasks in transporting the body during walking: generation or maintenance of forward velocity and support of the upper body (Winter, 1991). Several studies have investigated how muscles contribute to support and progression during healthy gait (Neptune et al, 2001;Anderson and Pandy, 2003;Neptune et al, 2004;Liu et al, 2006). The gluteus maximus and dorsiflexors have been shown to slow forward progression of the body mass center during early stance while providing vertical support, while the gluteus medius, soleus, and gastrocnemius propel the mass center forward and provide vertical support during late stance (Neptune et al, 2004;Liu et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

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Gluteus maximus and soleus compensate for simulated quadriceps atrophy and activation failure during walking

Thompson

Chaudhari

Schmitt

et al. 2013

Journal of Biomechanics

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Important activities of daily living, like walking and stair climbing, may be impaired by muscle weakness. In particular, quadriceps weakness is common in populations such as those with knee osteoarthritis (OA) and following ACL injury and may be a result of muscle atrophy or reduced voluntary muscle activation. While weak quadriceps has been strongly correlated with functional limitations in these populations, the important cause-effect relationships between abnormal lower extremity muscle function and patient function remain unknown. The purpose of this study was to explore possible muscle compensation strategies and changes in contribution to support and progression to maintain gait kinematics in response to two sources of quadriceps weakness: atrophy and activation failure. We used muscle-driven simulations to track normal gait kinematics in healthy subjects and applied simulated quadriceps weakness as atrophy and activation failure to evaluate compensation patterns associated with the individual sources of weakness. We found that the gluteus maximus and soleus muscles display the greatest ability to compensate for simulated quadriceps weakness. Relative to the baseline behavior of the muscles, the soleus compensates more to counteract activation deficits in the quadriceps and the gluteus maximus compensates more to counteract atrophy in the quadriceps. The development of this method for estimating the compensation strategies that are necessary to maintain normal gait will enable investigations of the role of muscle weakness in abnormal gait and inform potential rehabilitation strategies to improve such conditions.

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Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Gluteus maximus and soleus compensate for simulated quadriceps atrophy and activation failure during walking

Thompson

Chaudhari

Schmitt

et al. 2013

Journal of Biomechanics

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“…The latter finding is in accordance with an earlier study by Winter [19] who found that the amount of energy absorption by the ankle plantarflexors during weight acceptance was relatively insensitive to differences in walking speed. Furthermore, a recent simulation study showed that MG and SO deliver nearly all of the positive work during late to terminal stance (40-60% of the gait cycle) and that the contribution of these two muscles to forward progression is larger than that of all other muscles taken together [20]. The importance of this mechanism is underscored by the finding that late stance MG and SO activity continues to be affected by walking speed, even within the lowest speed range (0.28-0.06 m s −1 ).…”

Section: Lower Leg Musclesmentioning

confidence: 99%

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

et al. 2004

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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.

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“…To account for these differences, more complex models of walking use more detailed representations of the leg components, including springs and dampers, multisegments or neuromuscular structures (Siegler et al 1982;Gurp et al 1987;Pandy & Berme 1988;Neptune et al 2001;Pandy 2003;Zajac et al 2003). Although these models describe the dynamics of walking much closer than an inverted pendulum can, and indicate compliant leg behaviour to be relevant in walking, they are too complex to serve as conceptual models.…”

Section: Introductionmentioning

confidence: 99%

Compliant leg behaviour explains basic dynamics of walking and running

2006

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The basic mechanics of human locomotion are associated with vaulting over stiff legs in walking and rebounding on compliant legs in running. However, while rebounding legs well explain the stance dynamics of running, stiff legs cannot reproduce that of walking. With a simple bipedal spring-mass model, we show that not stiff but compliant legs are essential to obtain the basic walking mechanics; incorporating the double support as an essential part of the walking motion, the model reproduces the characteristic stance dynamics that result in the observed small vertical oscillation of the body and the observed out-of-phase changes in forward kinetic and gravitational potential energies. Exploring the parameter space of this model, we further show that it not only combines the basic dynamics of walking and running in one mechanical system, but also reveals these gaits to be just two out of the many solutions to legged locomotion offered by compliant leg behaviour and accessed by energy or speed.

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Contributions of the individual ankle plantar flexors to support, forward progression and swing initiation during walking

Cited by 913 publications

References 35 publications

Gluteus maximus and soleus compensate for simulated quadriceps atrophy and activation failure during walking

Gluteus maximus and soleus compensate for simulated quadriceps atrophy and activation failure during walking

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

Compliant leg behaviour explains basic dynamics of walking and running

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