The Influence of Tibialis Anterior Muscle Activity on Rearfoot Motion during Walking

1994 ◽  
Vol 15 (2) ◽  
pp. 75-79 ◽  
Author(s):  
Mark W. Cornwall ◽  
Thomas G. Mcpoil

The purpose of this study was to determine whether tibialis anterior muscle activity influences the rate of rearfoot motion during walking. Two-dimensional rearfoot motion was recorded from 23 feet. The feet were assigned to one of two experimental groups. Muscle activity was recorded from the tibialis anterior muscle using surface electrodes. The early pronators (N = 12) reached maximal pronation within the first 20K of the stance phase. The late pronators (N = 11) reached maximal pronation only after 40% of the stance phase. The results of a C-test showed that there was a significant difference (P < .05) in the time to minimal tibialis anterior muscle activity between the two groups. These results indicate that tibialis anterior muscle activity can influence rearfoot motion during the stance phase of walking. A clinician should consider the muscular system when evaluating and designing a treatment program for patients with foot-related problems. The results of this study also indicate that static nonweightbearing evaluations alone may not provide an accurate picture of the foot during walking.

1999 ◽  
Vol 86 (5) ◽  
pp. 1663-1669 ◽  
Author(s):  
A. L. Perlman ◽  
P. M. Palmer ◽  
T. M. McCulloch ◽  
D. J. Vandaele

The durations and temporal relationships of electromyographic activity from the submental complex, superior pharyngeal constrictor, cricopharyngeus, thyroarytenoid, and interarytenoid muscles were examined during swallowing of saliva and of 5- and 10-ml water boluses. Bipolar, hooked-wire electrodes were inserted into all muscles except for the submental complex, which was studied with bipolar surface electrodes. Eight healthy, normal, subjects produced five swallows of each of three bolus volumes for a total of 120 swallows. The total duration of electromyographic activity during the pharyngeal stage of the swallow did not alter with bolus condition; however, specific muscles did show a volume-dependent change in electromyograph duration and time of firing. Submental muscle activity was longest for saliva swallows. The interarytenoid muscle showed a significant difference in duration between the saliva and 10-ml water bolus. Finally, the interval between the onset of laryngeal muscle activity (thyroarytenoid, interarytenoid) and of pharyngeal muscle firing patterns (superior pharyngeal constrictor onset, cricopharyngeus offset) decreased as bolus volume increased. The pattern of muscle activity associated with the swallow showed a high level of intrasubject agreement; the presence of somewhat different patterns among subjects indicated a degree of population variance.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1288
Author(s):  
Keisuke Kubota ◽  
Masashi Sekiya ◽  
Toshiaki Tsuji

The purpose of this study was to determine the clinical effects of a training robot that induced eccentric tibialis anterior muscle contraction by controlling the strength and speed. The speed and the strength are controlled simultaneously by introducing robot training with two different feedbacks: velocity feedback in the robot controller and force bio-feedback based on force visualization. By performing quantitative eccentric contraction training, it is expected that the fall risk reduces owing to the improved muscle function. Evaluation of 11 elderly participants with months training period was conducted through a cross-over comparison test. The results of timed up and go (TUG) tests and 5 m walking tests were compared. The intergroup comparison was done using the Kruskal-Wallis test. The results of cross-over test indicated no significant difference between the 5-m walking time measured after the training and control phases. However, there was a trend toward improvement, and a significant difference was observed between the training and control phases in all subjects.


2014 ◽  
Vol 120 (5) ◽  
pp. 1125-1130 ◽  
Author(s):  
Torpon Vathana ◽  
Tim H. J. Nijhuis ◽  
Patricia F. Friedrich ◽  
Allen T. Bishop ◽  
Alexander Y. Shin

Object Choline acetyltransferase (ChAT) is an enzyme synthesized within the body of a motor neuron whose role is to form the neurotransmitter acetylcholine. Quantification of ChAT levels in motor or mixed nerves has been proposed to provide information regarding the viability of a proximal nerve stump for motor neurotization following brachial plexus injury. To do so requires information regarding normal ChAT levels and those in injured nerves, as well as the correlation of ChAT level determined at surgery with eventual motor recovery. The purpose of this study was to determine ChAT activity in the normal and injured sciatic/peroneal nerve in a rat model, evaluate the correlation between ChAT and motor recovery, find the relationship between ChAT activity and isometric muscle force, and elucidate the parallel between ChAT activity and acetylcholinesterase (AChE) activity. Methods Sixty animals were divided into 3 groups. The sciatic nerves in Group 1 were transected without repair. Nerves in Group 2 were transected and repaired. Nerves in Group 3 sustained a crush injury followed by transection and reconstruction. All animals were allowed 12 weeks of recovery followed by evaluation of ChAT levels in the peroneal nerve, correlated with measures of maximal isometric tibialis anterior muscle force and muscle weight (the operated side normalized to the control side). Karnovsky AChE staining of peroneal nerve segments was also compared with radiochemical assay of ChAT activity in the same nerve. Results A significant difference in the tibialis anterior isometric tetanic force and the tibialis anterior muscle weight index (TAMI) was noted between Group 1 and Groups 2 and 3 (p < 0.0001); no significant difference was found comparing Group 2 with Group 3. The correlation between the force measurement and the TAMI was 0.382. Both AChE measurement and ChAT activity demonstrated significantly fewer fibers in the operated nerve compared with the contralateral nerve. Intergroup variability could also be illustrated using these tests. The correlation coefficient between the isometric tetanic force measurement and the ChAT analysis in Groups 1 and 2 was 0.468. The correlation for the AChE staining and the isometric tetanic force measurement was 0.111. The correlation between the TAMI and the ChAT levels was 0.773. The correlation between the TAMI and the AChE-stained fibers was 0.640. Correlating AChE staining to the ChAT analysis produced a correlation of 0.712. Conclusions The great variability in all groups and weak correlations to the functional muscle assessments and the ChAT radiochemical assay made this technique an unreliable method of determining motor nerve viability.


1997 ◽  
Vol 01 (02) ◽  
pp. 95-109 ◽  
Author(s):  
W. Herzog ◽  
T. R. Leonard

The dynamic properties of the cat soleus muscle were studied in freely walking animal preparations. The force and EMG responses of the soleus following supramaximal, ins tants of the step cycle. The sensorimotor interactions of soleus with the medial head of the gastrocnemius (a functional agonist of the soleus at the ankle) and the tibialis anterior (a functional antagonist of soleus at the ankle) were studied by measuring their force and EMG responses following the artifical stimulation of the soleus nerve. Supramaximal nerve stimulation showed distinct increases in the soleus forces during the entire swing phase and the second part (after peak forces had been reached) of the stance phase. Soleus forces could only be increased slightly in the first part of stance (from paw contact to peak force). These results suggest that force production of the soleus is virtually maximal during the early phases of stance but is submaximal for the remainder of the step cycle. Forces and EMGs of the medial gastrocnemius muscle were affected by the soleus nerve stimulation only in the latter part of the swing phase. In these cases, the force and EMG of the medial gastrocnemius were reduced significantly for the step cycle following the perturbation. The active force production of soleus during late swing causes an inhibition of medial gastrocnemius activity and force. Forces and EMGs of the tibialis anterior muscle were always affected by the soleus nerve stimulation during the swing phase of the step cycle. In these case, the force EMG of the medial gastrocnemius were reduced significantly for the step cycle following the perturbation. The active force production of soleus during late swing causes an inhibition of medial gastrocnemius activity and force. Forces and EMGs of the tibialis anterior muscle were always affected by the soleus nerve stimulation during the swing phase of the step cycle. In these instances, forces and EMGs of the tibialis anterior were significantly increased compared to step cycles preceding or following the perturbation. Part of the force enhancement is caused by the stretch of the activated tibialis anterior by the soleus, and part of the enhancement is caused by reflex activation. No effects on forces or EMGs of the tibialis anterior were observed when the soleus nerve stimulation showed its effects during the stance phase of the step cycle. The results of theis study suggest that the magnitude and the quality of ensorimotor interactions of soleus with medial gastrocnemius and tibialis anterior depend on the phase of the step cycle. The strongest interactions appear to exist during the swing phase; no observable interactions were found during stance.


1996 ◽  
Vol 12 (3) ◽  
pp. 313-325 ◽  
Author(s):  
Vanessa R. Yingling ◽  
H. John Yack ◽  
Scott C. White

This study investigated whether rearfoot motion at heel contact during running attenuates the magnitude of the impact force traveling through the body. Fifteen subjects completed running trials for two conditions:(a) running on a treadmill at a self-selected speed and a cadence of 160 steps/min and (b) running at the same speed and cadence but with rearfoot motion limited by a medial wedge inserted into the subject's shoe. A pairedttest was used to test for differences between conditions in the peak accelerations of each accelerometer and the time to peak of the tibia acceleration. The predominant impact frequency and amplitude of the frequency peak were also tested for significant differences. No significant difference was found in the variables compared between the two conditions. The results demonstrated that restriction of rearfoot motion using a medial wedge during the initial 15% of the stance phase has no effect on the characteristics of the impulse wave at the tibia.


2013 ◽  
Vol 103 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Joanne S. Paton ◽  
Katherine Thomason ◽  
Karl Trimble ◽  
James E. Metcalfe ◽  
Jonathan Marsden

Background: We investigated whether a forefoot off-loading postoperative shoe (FOPS) alters standing posture, ankle muscle activity, and static postural sway and whether any effects are altered by wearing a shoe raise on the contralateral side. Methods: Posture, ankle muscle activity, and postural sway were compared in 14 healthy participants wearing either a FOPS or a control shoe with or without a contralateral shoe raise. Participants were tested under different sensory and support surface conditions. Additionally, reductions in peak pressure under the forefoot while walking were assessed with and without a contralateral shoe raise to determine whether the FOPS continued to achieve its primary off-loading function. Results: Compared with the control condition, wearing a FOPS moved the center of pressure posteriorly, increased tibialis anterior muscle activity, and reduced ankle plantarflexor activity. These changes decreased when a contralateral shoe raise was added. No difference in postural sway was found between footwear conditions. Forefoot peak pressure was always reduced when wearing the FOPS. Conclusions: The posterior shift in center of pressure toward and behind the ankle joint axis is believed to result in the increase in tibialis anterior muscle activity that now acts as the primary stabilizer around the ankle. Instability may, therefore, increase in patients with weak tibialis anterior muscles (eg, diabetic neuropathy) who need to wear offloading devices for ulcer management. We suggest that the addition of a contralateral shoe raise fitted with a FOPS may potentially be beneficial in maintaining stability while off-loading the forefoot in this patient group. (J Am Podiatr Med Assoc 103(1): 36–42, 2013)


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