scholarly journals A neuromechanical strategy for mediolateral foot placement in walking humans

2014 ◽  
Vol 112 (2) ◽  
pp. 374-383 ◽  
Author(s):  
Bradford L. Rankin ◽  
Stephanie K. Buffo ◽  
Jesse C. Dean
Keyword(s):  
Muscle Activity ◽  
Center Of Mass ◽  
Frontal Plane ◽  
Gluteus Medius ◽  
Swing Phase ◽  
Electromyographic Activity ◽  
Mechanical State ◽  
Foot Placement ◽  
The Right ◽  
Clinical Populations

Stability is an important concern during human walking and can limit mobility in clinical populations. Mediolateral stability can be efficiently controlled through appropriate foot placement, although the underlying neuromechanical strategy is unclear. We hypothesized that humans control mediolateral foot placement through swing leg muscle activity, basing this control on the mechanical state of the contralateral stance leg. Participants walked under Unperturbed and Perturbed conditions, in which foot placement was intermittently perturbed by moving the right leg medially or laterally during the swing phase (by ∼50–100 mm). We quantified mediolateral foot placement, electromyographic activity of frontal-plane hip muscles, and stance leg mechanical state. During Unperturbed walking, greater swing-phase gluteus medius (GM) activity was associated with more lateral foot placement. Increases in GM activity were most strongly predicted by increased mediolateral displacement between the center of mass (CoM) and the contralateral stance foot. The Perturbed walking results indicated a causal relationship between stance leg mechanics and swing-phase GM activity. Perturbations that reduced the mediolateral CoM displacement from the stance foot caused reductions in swing-phase GM activity and more medial foot placement. Conversely, increases in mediolateral CoM displacement caused increased swing-phase GM activity and more lateral foot placement. Under both Unperturbed and Perturbed conditions, humans controlled their mediolateral foot placement by modulating swing-phase muscle activity in response to the mechanical state of the contralateral leg. This strategy may be disrupted in clinical populations with a reduced ability to modulate muscle activity or sense their body's mechanical state.

scholarly journals Hip Muscle Activity During 3 Side-Lying Hip-Strengthening Exercises in Distance Runners

2012 ◽  
Vol 47 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Joseph M. McBeth ◽  
Jennifer E. Earl-Boehm ◽  
Stephen C. Cobb ◽  
Wendy E. Huddleston
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
External Rotation ◽  
Gluteus Maximus ◽  
Gluteus Medius ◽  
Electromyographic Activity ◽  
Maximal Voluntary Isometric Contraction ◽  
Strengthening Exercises ◽  
Hip Abduction ◽  
Hip Strengthening

Context: Lower extremity overuse injuries are associated with gluteus medius (GMed) weakness. Understanding the activation of muscles about the hip during strengthening exercises is important for rehabilitation. Objective: To compare the electromyographic activity produced by the gluteus medius (GMed), tensor fascia latae (TFL), anterior hip flexors (AHF), and gluteus maximus (GMax) during 3 hip-strengthening exercises: hip abduction (ABD), hip abduction with external rotation (ABD-ER), and clamshell (CLAM) exercises. Design: Controlled laboratory study. Setting: Laboratory. Patients or Other Participants: Twenty healthy runners (9 men, 11 women; age = 25.45 ± 5.80 years, height = 1.71 ± 0.07 m, mass = 64.43 ± 7.75 kg) participated. Intervention(s): A weight equal to 5% body mass was affixed to the ankle for the ABD and ABD-ER exercises, and an equivalent load was affixed for the CLAM exercise. A pressure biofeedback unit was placed beneath the trunk to provide positional feedback. Main Outcome Measure(s): Surface electromyography (root mean square normalized to maximal voluntary isometric contraction) was recorded over the GMed, TFL, AHF, and GMax. Results: Three 1-way, repeated-measures analyses of variance indicated differences for muscle activity among the ABD (F3,57 = 25.903, P<.001), ABD-ER (F3,57 = 10.458, P<.001), and CLAM (F3,57 = 4.640, P=.006) exercises. For the ABD exercise, the GMed (70.1 ± 29.9%), TFL (54.3 ± 19.1%), and AHF (28.2 ± 21.5%) differed in muscle activity. The GMax (25.3 ± 24.6%) was less active than the GMed and TFL but was not different from the AHF. For the ABD-ER exercise, the TFL (70.9 ± 17.2%) was more active than the AHF (54.3 ± 24.8%), GMed (53.03 ± 28.4%), and GMax (31.7 ± 24.1 %). For the CLAM exercise, the AHF (54.2 ± 25.2%) was more active than the TFL (34.4 ± 20.1%) and GMed (32.6 ± 16.9%) but was not different from the GMax (34.2 ± 24.8%). Conclusions: The ABD exercise is preferred if targeted activation of the GMed is a goal. Activation of the other muscles in the ABD-ER and CLAM exercises exceeded that of GMed, which might indicate the exercises are less appropriate when the primary goal is the GMed activation and strengthening.

scholarly journals Hip proprioceptive feedback influences the control of mediolateral stability during human walking

2015 ◽  
Vol 114 (4) ◽  
pp. 2220-2229 ◽  
Author(s):  
Devin C. Roden-Reynolds ◽  
Megan H. Walker ◽  
Camille R. Wasserman ◽  
Jesse C. Dean
Keyword(s):  
Sensory Feedback ◽  
Stance Phase ◽  
Gluteus Medius ◽  
Swing Phase ◽  
Proprioceptive Feedback ◽  
Quiet Standing ◽  
Bipedal Walking ◽  
Hip Abductor ◽  
The Right ◽  
Mediolateral Stability

Active control of the mediolateral location of the feet is an important component of a stable bipedal walking pattern, although the roles of sensory feedback in this process are unclear. In the present experiments, we tested whether hip abductor proprioception influenced the control of mediolateral gait motion. Participants performed a series of quiet standing and treadmill walking trials. In some trials, 80-Hz vibration was applied intermittently over the right gluteus medius (GM) to evoke artificial proprioceptive feedback. During walking, the GM was vibrated during either right leg stance (to elicit a perception that the pelvis was closer mediolaterally to the stance foot) or swing (to elicit a perception that the swing leg was more adducted). Vibration during quiet standing evoked leftward sway in most participants (13 of 16), as expected from its predicted perceptual effects. Across the 13 participants sensitive to vibration, stance phase vibration caused the contralateral leg to be placed significantly closer to the midline (by ∼2 mm) at the end of the ongoing step. In contrast, swing phase vibration caused the vibrated leg to be placed significantly farther mediolaterally from the midline (by ∼2 mm), whereas the pelvis was held closer to the stance foot (by ∼1 mm). The estimated mediolateral margin of stability was thus decreased by stance phase vibration but increased by swing phase vibration. Although the observed effects of vibration were small, they were consistent with humans monitoring hip proprioceptive feedback while walking to maintain stable mediolateral gait motion.

scholarly journals Rethinking Margin of Stability: Incorporating Step-To-Step Regulation to Resolve the Paradox

2021 ◽  
Author(s):  
Meghan Kazanski ◽  
Joseph P. Cusumano ◽  
Jonathan B. Dingwell
Keyword(s):  
Inverted Pendulum ◽  
Balance Control ◽  
Center Of Mass ◽  
Frontal Plane ◽  
Lateral Instability ◽  
Foot Placement ◽  
Margin Of Stability ◽  
Increased Risk ◽  
Mediolateral Stability ◽  
Balance Dynamics

ABSTRACTMaintaining frontal-plane stability is a major objective of human walking. Derived from inverted pendulum dynamics, the mediolateral Margin of Stability (MoSML) is frequently used to measure people’s frontal-plane stability on average. However, typical MoSML-based analyses deliver paradoxical interpretations of stability status. To address mediolateral stability using MoSML, we must first resolve this paradox. Here, we developed a novel framework that unifies the well-established inverted pendulum model with Goal-Equivalent Manifold (GEM)-based analyses to assess how humans regulate step-to-step balance dynamics to maintain mediolateral stability. We quantified the extent to which people corrected fluctuations in mediolateral center-of-mass state relative to a MoSML-defined candidate stability GEM in the inverted pendulum phase plane. Participants’ variability and step-to-step correction of tangent and perpendicular deviations from the candidate stability GEM demonstrate that regulation of balance dynamics involves more than simply trying to execute a constant-MoSML balance control strategy. Participants adapted these step-to-step corrections to mediolateral sensory and mechanical perturbations. How participants regulated mediolateral foot placement strongly predicted how they regulated center-of-mass state fluctuations, suggesting that regulation of center-of-mass state occurs as a biomechanical consequence of foot placement regulation. We introduce the Probability of Instability (PoI), a convenient statistic that accounts for step-to-step variance to properly predict instability likelihood on any given future step. Participants increased lateral PoI when destabilized, as expected. These lateral PoI indicated an increased risk of lateral instability, despite larger (i.e., more stable) average MoSML. PoI thereby explicitly predicts instability risk to decisively resolve the existing paradox that arises from conventional MoSML implementations.

NO ASSOCIATION AMONG GLUTEUS MEDIUS ACTIVITY, HIP ABDUCTION STRENGTH, AND KINEMATIC VARIABLES DURING SINGLE-LEG SQUAT IN YOUNG WOMEN WITH CHRONIC NONSPECIFIC LOW BACK PAIN

2020 ◽  
pp. 2050016
Author(s):  
Leonardo Intelangelo ◽  
Diego Bordachar ◽  
Cristian Mendoza ◽  
Nicolás Bevacqua ◽  
Alexandre Carvalho Barbosa
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Young Women ◽  
Frontal Plane ◽  
Gluteus Medius ◽  
Control Group ◽  
Electromyographic Activity ◽  
Adult Women ◽  
Low Back ◽  
Single Leg Squat

Background: Chronic nonspecific low back pain (CNSLBP) is the leading cause of long-term pain and disability. There is evidence suggesting a relationship between CNSLBP in adult women and altered hip kinematics and gluteus medius (GM) muscle function. However, this association has been less studied in young women. Objective: To assess the association between lower limb and pelvis kinematics in the frontal plane, and GM strength and electromyographic activity in young women with CNSLBP compared with an age-matched control group of asymptomatic women. Methods: In this cross-sectional study, 32 young women with CNSLBP ([Formula: see text] months of pain; Oswestry index range: 21–40%) and 20 healthy age-matched women were included. The frontal plane projection angle (FPPA) and contralateral pelvis drop (CPD) at the endpoint of the single-leg squat (SLS) test were measured through photogrammetry. Mean GM muscle activity during the SLS and peak isometric GM strength was measured using surface electromyography (sEMG) and hand-held dynamometry, respectively. Results: The Hotelling’s trace showed no significant differences between groups when the variables were considered as a composite ([Formula: see text]; [Formula: see text]). Also, the univariate results showed no individual differences between groups considering each variable separately. Conclusions: The results showed no association between CNSLBP, hip and pelvis kinematics, and GM strength and activity in young women.

Validating Determinants for an Alternate Foot Placement Selection Algorithm During Human Locomotion in Cluttered Terrain

2007 ◽  
Vol 98 (4) ◽  
pp. 1928-1940 ◽  
Author(s):  
Renato Moraes ◽  
Fran Allard ◽  
Aftab E. Patla
Keyword(s):  
Dynamic Stability ◽  
Center Of Mass ◽  
Frontal Plane ◽  
Human Locomotion ◽  
The Body ◽  
Selection Algorithm ◽  
Foot Placement ◽  
Double Support ◽  
One Step ◽  
Base Of Support

The goal of this study was to validate dynamic stability and forward progression determinants for the alternate foot placement selection algorithm. Participants were asked to walk on level ground and avoid stepping, when present, on a virtual white planar obstacle. They had a one-step duration to select an alternate foot placement, with the task performed under two conditions: free (participants chose the alternate foot placement that was appropriate) and forced (a green arrow projected over the white planar obstacle cued the alternate foot placement). To validate the dynamic stability determinant, the distance between the extrapolated center of mass (COM) position, which incorporates the dynamics of the body, and the limits of the base of support was calculated in both anteroposterior (AP) and mediolateral (ML) directions in the double support phase. To address the second determinant, COM deviation from straight ahead was measured between adaptive and subsequent steps. The results of this study showed that long and lateral choices were dominant in the free condition, and these adjustments did not compromise stability in both adaptive and subsequent steps compared with the short and medial adjustments, which were infrequent and adversely affected stability. Therefore stability is critical when selecting an alternate foot placement in a cluttered terrain. In addition, changes in the plane of progression resulted in small deviations of COM from the endpoint goal. Forward progression of COM was maintained even for foot placement changes in the frontal plane, validating this determinant as part of the selection algorithm.

scholarly journals Osteoarthrosis: Analyze of the Molar Bite Force, Thickness and Masticatory Efficiency

2020 ◽  
Vol 121 (2) ◽  
pp. 87-95
Author(s):  
Mariah Acioli Righetti ◽  
Oswaldo Luiz Stamato Taube ◽  
Marcelo Palinkas ◽  
Lígia Maria Napolitano Gonçalves ◽  
Danilo Stefani Esposto ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Muscle Thickness ◽  
Voluntary Contraction ◽  
Bite Force ◽  
Electromyographic Activity ◽  
Temporal Muscle ◽  
Significance Level ◽  
Masticatory Efficiency ◽  
Linear Envelope ◽  
The Right

Osteoarthrosis is a disorder of synovial joints, resulting from destruction of the cartilage and subchondral bone. The present study is aimed to investigate the molar bite force, thickness and efficiency of the masseter and temporalis muscles of subjects with osteoarthrosis. A total of forty-eight subjects participated in the study. They were distributed into two groups: with osteoarthrosis (n=24) and asymptomatic controls (n=24). Subjects were analyzed on the basis of maximal molar bite force (right and left side), thickness (mandibular rest and dental clenching in maximal voluntary contraction) and electromyographic activity of masticatory cycles through the linear envelope integral in habitual (raisins and peanuts) and non-habitual (Parafilm M) chewing of the masseter and temporalis muscles. All the data were analyzed statistically using t-test with a significance level of p≤0.05. There was no difference between groups in maximal molar bite force, muscle thickness and non-habitual chewing. Differences were found on the raisins (p=0.02) and peanuts (p=0.05) chewing for right temporal muscle, with reduced masticatory muscle efficiency in osteoarthrosis subjects. This study showed that osteoarthrosis induces negative changes in habitual chewing, highlighting the efficiency of the right temporalis muscles. The greater temporal muscle activity in subjects with osteoarthrosis may compromise chewing and consequently the nutritional status of adult subjects.

Effect of water depth on muscle activity of dogs when walking on a water treadmill

2018 ◽  
Vol 14 (2) ◽  
pp. 79-89
Author(s):  
S. Parkinson ◽  
A.P. Wills ◽  
G. Tabor ◽  
J.M. Williams
Keyword(s):  
Water Depth ◽  
Muscle Activity ◽  
Gluteus Medius ◽  
Lateral Malleolus ◽  
Greater Trochanter ◽  
Lateral Epicondyle ◽  
The Right ◽  
Water Treadmill ◽  
Post Hoc ◽  
Water Depths

Evidence-informed practice is currently lacking in canine hydrotherapy. This study aimed to investigate if the estimated workload of the gluteus medius (GM) and longissimus dorsi (LD) increased in dogs at different water depths when walking on a water treadmill. Seven dogs were walked for 2 min continuously on a water treadmill at depths of no submersion (depth 1), mid-tarsal (depth 2), between lateral malleolus and lateral epicondyle (depth 3) and between the lateral epicondyle and greater trochanter (depth 4). Continuous electromyographic data from the right and left sides of GM and LD were collected simultaneously during exercise. Friedman’s analyses with post-hoc Wilcoxon tests established if significant differences in GM and LD muscle activity occurred between the water depths for mean estimated-workload. Significant differences occurred in estimated-workload in GM and LD between water depths (P<0.05). Mean estimated-workload decreased in the right and left GM between depths 2 (mid-tarsal) and 3 (between lateral malleolus and epicondyle) (P<0.007) and depths 2 and 4 (between lateral epicondyle and greater trochanter) (P<0.001), a pattern which was repeated for left and right LD (P<0.007). Right GM mean estimated-workload increased between depth 1 (no submersion) and depth 2 only (P<0.013). Water depth influences GM and LD activity in dogs walking on a water treadmill. Increasing knowledge of canine locomotion in water treadmills could be used to inform individualised rehabilitation regimes for dogs undertaking hydrotherapy.

Turning Strategies During Human Walking

1999 ◽  
Vol 81 (6) ◽  
pp. 2914-2922 ◽  
Author(s):  
K. Hase ◽  
R. B. Stein
Keyword(s):  
Postural Sway ◽  
Gluteus Medius ◽  
Biceps Femoris ◽  
The Body ◽  
Erector Spinae ◽  
Human Walking ◽  
Step Cycle ◽  
Foot Placement ◽  
The Right ◽  
Step Turn

Turning strategies during human walking. The mechanisms involved in rapidly turning during human walking were studied. Subjects were asked to walk at a comfortable speed and to turn toward the instructed direction as soon as they felt an electrical stimulus to the superficial peroneal nerve. Stimuli were presented repeatedly at random over 10- to 15-min periods of walking for turning in both directions. Electromyograms (EMGs), joint angular movements of the right leg, and forces under both feet were recorded. The step cycle was divided into 16 parts, and the responses to stimuli in each part were analyzed separately. Two turning strategies were used, depending on which leg was placed in front for braking. For example, to turn to the right when the right foot was placed in front, subjects generally altered direction by spinning the body around the right foot (spin turn). To turn left when the right foot was in front, subjects shifted weight to the right leg, externally rotated the left hip, stepped onto the left leg, and continued turning until the right leg stepped in the new direction (step turn). The step turn is easy and stable because the base of support during the turn is much wider than in the spin turn, so some subjects used it in all parts of the cycle. Initially, the deceleration of walking is similar to a rapid stopping task, which has been previously examined. The deceleration mechanism involves a sequence of distal-to-proximal activation of muscles on one side of the body (soleus, biceps femoris, and erector spinae). This pattern is similar to the “ankle strategy” used in postural control during forward sway. The control of foot placement in the swing leg and muscle activities for rotating the trunk in the stance leg occurred within a step after the cue. The action of ankle inverters and elevation of the pelvis by activity of gluteus medius may contribute to the control of trunk rotation. This activity was closely related to the timing of the opposite foot strike, independent of the part of the step cycle when the stimulus was applied. In most subjects, the turn was completed without resetting the underlying walking rhythm. This first EMG analysis of rapid turning shows how common strategies for postural sway and stopping can be combined with one of two turning strategies. This simplifies the complex task of turning at a random time in the step cycle.

scholarly journals The electromyographic activity characteristics of the gluteus medius muscle before and after total hip arthroplasty

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Konrad Kopeć _ ◽  
Przemysław Bereza ◽  
Grzegorz Sobota ◽  
Grzegorz Hajduk ◽  
Damian Kusz
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Muscle Activity ◽  
Weight Bearing ◽  
Gluteus Medius ◽  
Contralateral Side ◽  
Proper Function ◽  
Electromyographic Activity ◽  
Gluteus Medius Muscle ◽  
Total Hip

Purpose: The clinical outcomes of total hip arthroplasty are influenced by the correct muscle function that determines good, longterm and proper function of the artificial joint. The aim of the study was to analyze the electromyographic activity of the gluteus medius muscle in patients with hip osteoarthritis and after arthroplasty in various static weight bearing conditions, both on the affected and contralateral side. Methods: The prospective study involved 70 patients qualified for hip replacement. Patients underwent a surface electromyography of the gluteus medius muscle which involved the Trendelenburg test. The normalized results were obtained for both hips, preoperatively and 6 months after arthroplasty. Results: The only muscle activity differences were found at a full load condition of lower limb. In the preoperative assessment, the activity of the gluteus medius muscle was greater on the side qualified for surgery. After arthroplasty and the rehabilitation period, the muscle activity on the operated side decreased and significantly increased on the contralateral side. Detailed analysis of the contralateral side revealed relationship with osteoarthritis. Previous hip arthroplasty of that side resulted in lower muscle activity, similar to fully functional joints. Conclusion: The activity characteristics of the gluteus medius muscle vary depending on the condition of the joint, and the characteristics change as a result of the surgical procedure performed on both the operated and contralateral sides. These dependencies should be taken into account in the rehabilitation process, especially at the side opposite to the operated one.

scholarly journals Associations of Electromyographic Activity of Anterior T aphic Activity of Anterior Temporalis Muscles, Sex, and Occlusal Classes in Asymptomatic Young Adults

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Aneta Wieczorek ◽  
◽  
Marcin Czarnek ◽  
Jolanta E. Loster ◽  
◽  
...  
Keyword(s):  
Young Adults ◽  
Muscle Activity ◽  
Masticatory Muscles ◽  
Class I ◽  
Electromyographic Activity ◽  
Mandibular Movement ◽  
Occlusal Contact ◽  
Contact Points ◽  
The Right ◽  
Craniofacial Complex

Symmetry evaluation of the craniofacial complex generally involves models of mandibular movement and masticatory muscle activity, especially during the growth of the craniofacial complex. Objectives: The aim of the study was to determine what, if any, associations exist between the activity of the masticatory muscles, sex, and occlusal classes in asymptomatic young adults. Methods:18-year-old volunteers, showing no symptoms of TMD based on an RDC/TMD examination, were included in the study.Surface electromyography (sEMG) recording was used to quantify the activity of masticatory muscles. The occlusal contact points were analyzed using a T-scan III Evolution 7.01 device. Occlusal classes were graded, employing an approach based on plaster study models. Results: In Class I–II subjects, we found significant differences only in the voltage of LTA in correlation with the gender and occlusal Class. Conclusions: Our findings show that the electromyography voltage of LTA significantly differs according to sex and occlusal Class. The voltage is higher in the female occlusal class II group, while the voltage is less in the male Class I and II group. This may be responsible for the symmetry index, which shows the predominance of the right-side muscles in all gender and occlusal groups.

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