A dynamic optimization technique for predicting muscle forces in the swing phase of gait

Davy, Dwight T.; Audu, Musa L.

doi:10.1016/0021-9290(87)90310-1

Cited by 318 publications

(171 citation statements)

References 25 publications

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“…The length range of the ascending part of the active length-force curve was calculated as the length range between active slack length and optimum length. Passive forces as a function of MTU length were fitted to a double exponential function as f(x) ϭ a·e b·x ϩ c·e d·x (R 2 Ͼ 0.99, mean R 2 ϭ 1.00) (9). A: lateral view of the left rat hindlimb with anterior and posterior crural compartments exposed, and the experimental setup.…”

Section: Animalsmentioning

confidence: 99%

Muscle-specific changes in length-force characteristics of the calf muscles in the spastic Han-Wistar rat

Olesen

Jensen

Uhlendorf

et al. 2014

Journal of Applied Physiology

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Olesen AT, Jensen BR, Uhlendorf TL, Cohen RW, Baan GC, Maas H. Muscle-specific changes in length-force characteristics of the calf muscles in the spastic Han-Wistar rat. J Appl Physiol 117: 989-997, 2014. First published September 4, 2014 doi:10.1152/japplphysiol.00587.2014.-The purpose of the present study was to investigate muscle mechanical properties and mechanical interaction between muscles in the lower hindlimb of the spastic mutant rat. Length-force characteristics of gastrocnemius (GA), soleus (SO), and plantaris (PL) were assessed in anesthetized spastic and normally developed Han-Wistar rats. In addition, the extent of epimuscular myofascial force transmission between synergistic GA, SO, and PL, as well as between the calf muscles and antagonistic tibialis anterior (TA), was investigated. Active length-force curves of spastic GA and PL were narrower with a reduced maximal active force. In contrast, active length-force characteristics of spastic SO were similar to those of controls. In reference position (90°ankle and knee angle), higher resistance to ankle dorsiflexion and increased passive stiffness was found for the spastic calf muscle group. At optimum length, passive stiffness and passive force of spastic GA were decreased, whereas those of spastic SO were increased. No mechanical interaction between the calf muscles and TA was found. As GA was lengthened, force from SO and PL declined despite a constant muscle-tendon unit length of SO and PL. However, the extent of this interaction was not different in spastic rats. In conclusion, the effects of spasticity on length-force characteristics were muscle specific. The changes observed for GA and PL muscles are consistent with the changes in limb mechanics reported for human patients. Our results indicate that altered mechanics in spastic rats cannot be attributed to differences in mechanical interaction, but originate from individual muscular structures. muscle spasticity; mechanical properties; myofascial force transmission; muscle stiffness MUSCLE SPASTICITY HAS BEEN defined as a "velocity-depended resistance to stretch" (24) and arises secondary to upper motoneuron lesions with cerebral palsy and stroke as the most common examples (12). Individuals suffering from spasticity typically experience muscle weakness, enhanced joint stiffness, increased muscle tone, reduced range of joint motion, increased antagonistic co-contraction, and exaggerated reflexes (1,3,6,12,13,32,41,48). These effects severely impair the ability to perform daily activities, and treatment is often needed.To asses whether some of these symptoms are related to altered mechanical properties of muscle-tendon units (MTUs), passive and active length-force characteristics have been estimated as joint moment as a function of gastrocnemius (GA) fascicle length. Spastic GA was found to be stiffer than normally developed in such studies (2, 3). The active lengthforce curve of the spastic GA was narrower and the optimum length was shifted to a shorter fascicle length than in normally deve...

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Section: Animalsmentioning

confidence: 99%

Muscle-specific changes in length-force characteristics of the calf muscles in the spastic Han-Wistar rat

Olesen

Jensen

Uhlendorf

et al. 2014

Journal of Applied Physiology

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“…The alteration in movement pattern associated with "quadriceps avoidance," may also represent an increase flexor activity of the hamstrings [44], or the gastrocnemius [45] which have been supported by EMG studies. However, altered movement patterns persist following ACLR [46,47], suggesting that instability is not the sole cause of the gait adaptation.…”

Section: Biomechanics In Acl-deficient Knees and Aclr Patientsmentioning

confidence: 99%

“…Although a number of studies have applied bioinformatic modelling and simulation to understand the muscular adaptations of the gait cycle [47,51,52], only one of these has quantified the effect of muscle compensation on knee instability in ACL-injured patients. Liu and Maitland found that 56% of peak isometric hamstrings force was required to restore anterior tibial translation in the ACL-deficient knee to the values observed in normal gait [53].…”

Section: Biomechanics In Acl-deficient Knees and Aclr Patientsmentioning

confidence: 99%

Prehabilitation: The Void in the Management of Anterior Cruciate Ligament Injuries—A Clinical Review

Shaarani

Moyna

Moran

et al. 2012

ISRN Rehabilitation

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The rehabilitation of patients undergoing anterior cruciate ligament (ACL) reconstruction requires symmetry in bilateral quadriceps strength and adequate proprioception capabilities prior to return to preoperative level of activity or sport. This is the limiting factor and can delay the time that patients can return to play. There is little literature on pre-operative physiotherapy or prehabilitation of patient with ACL injury. This paper discusses the anatomy, biomechanics, surgical decision making, and the current knowledge of preoperative training or "prehabilitation" in patients awaiting ACL reconstruction.

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“…Joint angle and muscle lengths are calculated by mapping this data onto a musculoskeletal human model [1][2][3][4]. The fact that the solution is not necessarily uniquely determined remains a problem, but once boundary conditions are determined, tension in wholebody muscles can be determined [5,6]. Systems such as SIMM [7] (Delp et al) and AnyBody [8] (Rasmussen et al) have been marketed to analyze and simulate musculoskeletal human model movement.…”

Section: Introductionmentioning

confidence: 99%

Spinal Information Processing and its Application to Motor Learning Support

Otake

Nakamura²

2005

J. Robot. Mechatron.

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We designed motor learning support for acquiring motor skills involving neural mechanisms. We should be able to acquire neural information by analyzing whole-body muscle data, because the nervous system controls the musculoskeletal system and lengths and forces information is fed back to the nervous system. Motor information is calculated by mapping motioncapture data on to a musculoskeletal human model. Neural information represents the set of motor information on the muscles innervated by the arbitrary spinal cord segment. Neural information processing is proposed which calculates correlation among the neural information. We demonstrate the effectiveness of our proposal by experimental results of "kesagiri".

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A dynamic optimization technique for predicting muscle forces in the swing phase of gait

Cited by 318 publications

References 25 publications

Muscle-specific changes in length-force characteristics of the calf muscles in the spastic Han-Wistar rat

Muscle-specific changes in length-force characteristics of the calf muscles in the spastic Han-Wistar rat

Prehabilitation: The Void in the Management of Anterior Cruciate Ligament Injuries—A Clinical Review

Spinal Information Processing and its Application to Motor Learning Support

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