scholarly journals Ankle muscle responses during perturbed walking with blocked ankle joints

2019 ◽  
Vol 121 (5) ◽  
pp. 1711-1717 ◽  
Author(s):  
Mark Vlutters ◽  
Edwin H. F. van Asseldonk ◽  
Herman van der Kooij
Keyword(s):  
Ankle Joint ◽  
Balance Control ◽  
Muscle Length ◽  
Joint Rotation ◽  
Long Latency ◽  
Ankle Joints ◽  
Ankle Foot Orthoses ◽  
Ankle Muscle ◽  
Length Changes ◽  
Muscle Responses

The ankle joint muscles can contribute to balance during walking by modulating the center of pressure and ground reaction forces through an ankle moment. This is especially effective in the sagittal plane through ankle plantar- or dorsiflexion. If the ankle joints were to be physically blocked to make an ankle strategy ineffective, there would be no functional contribution of these muscles to balance during walking, nor would these muscles generate afferent output regarding ankle joint rotation. Consequently, ankle muscle activation for the purpose of balance control would be expected to disappear. We have performed an experiment in which subjects received anteroposterior pelvis perturbations during walking while their ankle joints could not contribute to the balance recovery. The latter was realized by physically blocking the ankle joints through a pair of modified ankle-foot orthoses. In this article we present the lower limb muscle activity responses in reaction to these perturbations. Of particular interest are the tibialis anterior and gastrocnemius medialis muscles, which could not contribute to the balance recovery through the ankle joint or encode muscle length changes caused by ankle joint rotation. Yet, these muscles showed long-latency responses, ~100 ms after perturbation onset. The response amplitudes were dependent on the perturbation magnitude and direction, as well as the state of the leg. The results imply that ankle muscle responses can be evoked without changes in proprioceptive information of those muscles through ankle rotation. This suggest a more centralized regulation of balance control, not strictly related to the ankle joint kinematics. NEW & NOTEWORTHY Walking human subjects received forward-backward perturbations at the pelvis while wearing “pin-shoes,” a pair of modified ankle-foot orthoses that physically blocked ankle joint movement and reduced the base of support of each foot to a single point. The lower leg muscles showed long-latency perturbation-dependent activity changes, despite having no functional contributions to balance control through the ankle joint and not having been subjected to muscle length changes through ankle joint rotation.

The Influence of Profession on Functional Ankle Stability in Musicians

2010 ◽  
Vol 25 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Susanne Rein ◽  
Tobias Fabian ◽  
Hans Zwipp ◽  
Jan Heineck ◽  
Stephan Weindel
Keyword(s):  
Reaction Time ◽  
Ankle Joint ◽  
Postural Balance ◽  
Balance Control ◽  
Ankle Sprains ◽  
Exact Test ◽  
Work Related ◽  
Ankle Stability ◽  
Ankle Joints ◽  
The Right

OBJECTIVE: The aim of this study was to examine the influence of extensive work-related use of the feet on functional ankle stability among musicians. METHODS: Thirty professional organists were compared to professional pianists and controls. All participants completed a questionnaire. Range of motion (ROM), peroneal reaction time, and positional sense tests of the ankle were measured. The postural balance control was investigated with the Biodex Stability System for the stable level 8 and unstable level 2. Statistical analysis was done with the Kruskal-Wallis test, Mann-Whitney test with Bonferroni-Holm correction, and Fisher’s exact test. RESULTS: Nine of 30 organists compared to 5 of 30 pianists and controls reported ankle sprains in their medical history. Pianists had a significant increased flexion of both ankle joints compared to organists (p≤0.01) and increased flexion of the right ankle joint compared to controls (p=0.02). The positional sense test and postural balance control showed no significant differences among groups. The peroneal reaction time of the right peroneus longus muscle was significantly increased in pianists compared to controls (p=0.008). CONCLUSIONS: Organists have shown a high incidence of ankle sprains. Despite their extensive work-related use of the ankle joints, organists have neither increased functional ankle stability nor increased ROM of their ankle joints in comparison to controls. Pianists have increased flexion of the ankle joint, perhaps due to the exclusive motion of extension and flexion while using the pedals. To minimize injuries of the ankle and improve functional ankle stability as well as balance control, proprioceptive exercises of the ankle in daily training programs are recommended.

scholarly journals A Model to Predict the Effect of Ankle Joint Misalignment on Calf Band Movement in Ankle-Foot Orthoses

2007 ◽  
Vol 31 (1) ◽  
pp. 76-87 ◽  
Author(s):  
Stefania Fatone ◽  
Andrew H. Hansen
Keyword(s):  
Ankle Joint ◽  
Walking Speed ◽  
Sagittal Plane ◽  
Plantar Flexion ◽  
Dimensional Model ◽  
Ankle Foot Orthosis ◽  
Ankle Joints ◽  
Ankle Foot Orthoses ◽  
Foot Orthosis ◽  
Anterior Posterior

Accurate alignment of anatomical and mechanical joint axes is one of the major biomechanical principles pertaining to articulated orthoses, yet knowledge of the potential effects of axis misalignment is limited. The purpose of this project was to model the effects of systematic linear (proximal-distal and anterior-posterior) misalignments of single axis mechanical ankle joints in an ankle-foot orthosis (AFO) in order to determine the degree and direction of calf band travel that would occur over a functional range of motion. Sagittal plane misalignments of the ankle joint centres of an AFO were simulated using a simple two-dimensional model for both a range of ankle angles and a typical able-bodied ankle kinematic curve for self-selected normal walking speed. The model assumed that no movement occurred between the foot and the foot-plate of the AFO. The model predicted that for anterior (positive horizontal) misalignments, dorsiflexion movements would cause the calf band to travel proximally (i.e., up the leg) and plantar flexion movements would cause the calf band to travel distally (i.e., down the leg). The opposite was predicted for posterior (negative horizontal) misalignments. Proximal (positive vertical) misalignments would cause only distal movements of the calf band while distal (negative vertical) misalignments would cause only proximal movements of the calf band. Anterior-posterior misalignments were found to have a much larger effect on the amount of calf band travel than proximal-distal misalignments.

Poster 60: Impact of the Ankle-Foot Orthoses on 3D Ankle Joint Rotation in Children with Spastic CP

PM&R ◽  
2009 ◽  
Vol 1 ◽  
pp. S129-S130
Author(s):  
Frederick T. Klingbeil ◽  
Xue-Cheng Liu ◽  
Elizabeth Moberg-Wolff
Keyword(s):  
Ankle Joint ◽  
Foot Orthoses ◽  
Joint Rotation ◽  
Ankle Foot Orthoses

scholarly journals Identification of Individual Muscle Length Parameters from Measurements of Passive Joint Moment Around the Ankle Joint

2012 ◽  
Vol 7 (2) ◽  
pp. 168-176 ◽  
Author(s):  
Hisashi NAITO ◽  
Yasushi AKAZAWA ◽  
Ayu MIURA ◽  
Takeshi MATSUMOTO ◽  
Masao TANAKA
Keyword(s):  
Ankle Joint ◽  
Muscle Length ◽  
Joint Moment ◽  
Passive Joint ◽  
Individual Muscle

Muscle dynamics in skipjack tuna: timing of red muscle shortening in relation to activation and body curvature during steady swimming

1999 ◽  
Vol 202 (16) ◽  
pp. 2139-2150 ◽  
Author(s):  
R.E. Shadwick ◽  
S.L. Katz ◽  
K.E. Korsmeyer ◽  
T. Knower ◽  
J.W. Covell
Keyword(s):  
Fork Length ◽  
Muscle Length ◽  
The Body ◽  
Emg Activity ◽  
Skipjack Tuna ◽  
Force Transmission ◽  
Muscle Strain ◽  
Muscle Shortening ◽  
Red Muscle ◽  
Length Changes

Cyclic length changes in the internal red muscle of skipjack tuna (Katsuwonus pelamis) were measured using sonomicrometry while the fish swam in a water tunnel at steady speeds of 1.1-2.3 L s(−)(1), where L is fork length. These data were coupled with simultaneous electromyographic (EMG) recordings. The onset of EMG activity occurred at virtually the same phase of the strain cycle for muscle at axial locations between approximately 0.4L and 0.74L, where the majority of the internal red muscle is located. Furthermore, EMG activity always began during muscle lengthening, 40–50 prior to peak length, suggesting that force enhancement by stretching and net positive work probably occur in red muscle all along the body. Our results support the idea that positive contractile power is derived from all the aerobic swimming muscle in tunas, while force transmission is provided primarily by connective tissue structures, such as skin and tendons, rather than by muscles performing negative work. We also compared measured muscle length changes with midline curvature (as a potential index of muscle strain) calculated from synchronised video image analysis. Unlike contraction of the superficial red muscle in other fish, the shortening of internal red muscle in skipjack tuna substantially lags behind changes in the local midline curvature. The temporal separation of red muscle shortening and local curvature is so pronounced that, in the mid-body region, muscle shortening at each location is synchronous with midline curvature at locations that are 7–8 cm (i.e. 8–10 vertebral segments) more posterior. These results suggest that contraction of the internal red muscle causes deformation of the body at more posterior locations, rather than locally. This situation represents a unique departure from the model of a homogeneous bending beam, which describes red muscle strain in other fish during steady swimming, but is consistent with the idea that tunas produce thrust by motion of the caudal fin rather than by undulation of segments along the body.

Sarcomere length control in striated muscle

1982 ◽  
Vol 242 (3) ◽  
pp. H411-H420 ◽  
Author(s):  
R. van Heuningen ◽  
W. H. Rijnsburger ◽  
H. E. ter Keurs
Keyword(s):  
Sarcomere Length ◽  
Striated Muscle ◽  
Feedforward Control ◽  
Muscle Length ◽  
Transient Behavior ◽  
Loop Filter ◽  
Internal Position ◽  
Optimal Damping ◽  
Internal Velocity ◽  
Muscle Responses

A system that makes control of muscle length (ML), sarcomere length (SL), and force (F) possible in striated muscle preparations is described. SL was measured by light diffraction techniques and two diffractometers. Control was performed by influencing ML with a penmotor system with a frequency response of 190 Hz. SL or F could be controlled by interrupting the internal position (i.e., ML) feedback of the motor and by closing the respective loop. Velocity feedback of the motor through an internal velocity coil was maintained in all cases for optimal damping. Steady-state error of the system was minimized by an integrating loop filter. The feedback path was selected by means of potentiometers or analog switches. Electronic stops in the circuit protected the muscle against excessive stretch and load. A microprocessor-based average-response computer could be used for feedforward control to eliminate noise or to analyze longitudinal uniformity of the muscle. Responses of rat cardiac trabeculae during SL and F control are shown. Transient behavior of SL and F during control and measures to eliminate the transients are discussed.

Evaluation of Locomotor Function in Patients with CP Based on Muscle Length Changes

2016 ◽  
pp. 161-168 ◽  
Author(s):  
Katarzyna Nowakowska ◽  
Robert Michnik ◽  
Katarzyna Jochymczyk-Woźniak ◽  
Jacek Jurkojć ◽  
Ilona Kopyta
Keyword(s):  
Muscle Length ◽  
Locomotor Function ◽  
Length Changes

Transient responses and continuous behavior of active smooth muscle during controlled stretches

1982 ◽  
Vol 242 (3) ◽  
pp. C146-C158 ◽  
Author(s):  
R. A. Meiss
Keyword(s):  
Steady State ◽  
Smooth Muscles ◽  
Muscle Length ◽  
Initial Slope ◽  
Stretch Rate ◽  
Rate Dependent ◽  
Upward Slope ◽  
Length Changes ◽  
State Force ◽  
The Relationship

Controlled length changes were imposed on mesotubarium superius and ovarian ligament smooth muscles from the reproductive tracts of female rabbits in constant estrus. Stretches of up to 35% of the muscle length were applied during isometric contraction, relaxation, and steady-state force levels. Force was continuously monitored and was plotted as a function of length. During constant velocity stretches there was an initial steep rise in force, a rapid downward deviation from the initial slope, and a long region with a constant upward slope. Stretches made during contraction showed smaller initial rises in force and steeper linear portions than did identical comparison stretches made during relaxation. The value of the slope was independent of the prior developed force, but it did depend on whether the muscle was contracting or relaxing. During contraction and steady-state force levels, the slope was independent of the stretch rate, but it was strongly rate dependent during relaxation. Changes in the stretch rate during stretch caused associated changes in muscle force; the relationship was curvilinear and was exaggerated during relaxation. The findings are placed in the context of a sliding-filament--cross-bridge hypothesis.

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