scholarly journals Biomechanical effects of foot orthoses with and without a lateral bar in individuals with cavus feet during comfortable and fast walking

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248658
Author(s):  
Gabriel Moisan ◽  
Martin Descarreaux ◽  
Vincent Cantin
Keyword(s):  
Vastus Lateralis ◽  
Statistical Parametric Mapping ◽  
Knee Kinematics ◽  
Gluteus Medius ◽  
Knee Extension ◽  
Ankle Dorsiflexion ◽  
Foot Orthoses ◽  
Experimental Conditions ◽  
Peroneus Longus ◽  
Fast Speed

Background/purpose The biomechanical effects of foot orthoses (FOs) with and without a lateral bar compared to a control condition during walking at different speeds are still unknown. The objective of this study was to compare the biomechanical effects of functional FOs with and without a lateral bar to a control condition during comfortable walking in individuals with cavus feet and determine if their effects change at a fast speed. Methods Fifteen individuals with cavus feet (age: 25.3 ± 5.8 yrs) walked under two experimental conditions (FOs with and without a lateral bar) and a control condition (shoes only) at comfortable (CW) and fast (FW) speeds. The outcome measures were ankle and knee angles and gluteus medius, vastus lateralis, gastrocnemius lateralis, gastrocnemius medialis, peroneus longus and tibialis anterior electromyography (EMG) amplitudes during the stance phase of walking and were compared between the FOs and a control condition using one-dimensional statistical parametric mapping. Results During CW, both FOs decreased ankle dorsiflexion and increased knee extension angles compared to no FOs. FOs with a lateral bar also decreased peroneus longus EMG amplitudes. During FW, FOs with and without a lateral bar decreased ankle dorsiflexion angles compared to no FOs. Conclusion Both types of FOs had different effects on the biomechanics of the lower limb compared to a control condition. The decreased peroneus longus EMG amplitudes during CW in individuals with cavus feet could have important clinical implications in other populations, such as individuals with painful cavus feet. The orthoses only affected the ankle dorsiflexion angles at a fast speed and no EMG amplitude or knee kinematics effects were observed. Further studies assessing the ankle kinematics and kinetics effects of these orthoses are needed to improve our understanding of their mechanism of action and inform future efficacy trials.

scholarly journals Muscle-Activation Onset Times With Shoes and Foot Orthoses in Participants With Chronic Ankle Instability

2015 ◽  
Vol 50 (7) ◽  
pp. 688-696 ◽  
Author(s):  
Bart Dingenen ◽  
Louis Peeraer ◽  
Kevin Deschamps ◽  
Steffen Fieuws ◽  
Luc Janssens ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Linear Model ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Ankle Instability ◽  
Chronic Ankle Instability ◽  
Foot Orthoses ◽  
Experimental Conditions ◽  
Peroneus Longus ◽  
Hip Muscles

Context Participants with chronic ankle instability (CAI) use an altered neuromuscular strategy to shift weight from double-legged to single-legged stance. Shoes and foot orthoses may influence these muscle-activation patterns. Objective To evaluate the influence of shoes and foot orthoses on onset times of lower extremity muscle activity in participants with CAI during the transition from double-legged to single-legged stance. Design Cross-sectional study. Setting Musculoskeletal laboratory. Patients or Other Participants A total of 15 people (9 men, 6 women; age = 21.8 ± 3.0 years, height = 177.7 ± 9.6 cm, mass = 72.0 ± 14.6 kg) who had CAI and wore foot orthoses were recruited. Intervention(s) A transition task from double-legged to single-legged stance was performed with eyes open and with eyes closed. Both limbs were tested in 4 experimental conditions: (1) barefoot (BF), (2) shoes only, (3) shoes with standard foot orthoses, and (4) shoes with custom foot orthoses (SCFO). Main Outcome Measure(s) The onset of activity of 9 lower extremity muscles was recorded using surface electromyography and a single force plate. Results Based on a full-factorial (condition, region, limb, vision) linear model for repeated measures, we found a condition effect (F3,91.8 = 9.39, P < .001). Differences among experimental conditions did not depend on limb or vision condition. Based on a 2-way (condition, muscle) linear model within each region (ankle, knee, hip), earlier muscle-activation onset times were observed in the SCFO than in the BF condition for the peroneus longus (P < .001), tibialis anterior (P = .003), vastus medialis obliquus (P = .04), and vastus lateralis (P = .005). Furthermore, the peroneus longus was activated earlier in the shoes-only (P = .02) and shoes-with-standard-foot-orthoses (P = .03) conditions than in the BF condition. No differences were observed for the hip muscles. Conclusions Earlier onset of muscle activity was most apparent in the SCFO condition for ankle and knee muscles but not for hip muscles during the transition from double-legged to single-legged stance. These findings might help clinicians understand how shoes and foot orthoses can influence neuromuscular control in participants with CAI.

scholarly journals Lower limb biomechanics in individuals with chronic ankle instability during gait: a case-control study

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Gabriel Moisan ◽  
Camille Mainville ◽  
Martin Descarreaux ◽  
Vincent Cantin
Keyword(s):  
Lower Limb ◽  
Stance Phase ◽  
Ankle Instability ◽  
Vastus Lateralis ◽  
Gluteus Medius ◽  
Healthy Controls ◽  
Peroneus Longus ◽  
Ankle Inversion ◽  
Ankle Eversion ◽  
Longus Muscle

Abstract Background Individuals with chronic ankle instability (CAI) exhibit many biomechanical changes to lower limbs during walking. However, only a few studies have investigated the differences in lower limb biomechanics of individuals with CAI compared to healthy controls using a comprehensive approach including kinematic, kinetic and electromyography (EMG) measures. Consequently, the theoretical framework explaining the biomechanical adaptations in individuals with CAI is mostly based on the results of studies including heterogenous methods and participants’ specificities (e.g., level of disability). More studies using a comprehensive approach are needed to better understand the biomechanical adaptations associated with CAI. The objective of this case-control study was to identify the kinematic, kinetic and EMG differences between individuals with CAI and healthy controls during walking. Methods Twenty-eight individuals with CAI and 26 healthy controls were recruited to walk at a self-selected speed during which lower limb kinematics, kinetics and EMG were analysed. Ankle and knee angles and moments as well as gluteus medius, vastus lateralis, gastrocnemius lateralis, peroneus longus and tibialis anterior muscles activity were compared between the CAI and control groups using one-dimensional statistical parametric mapping. Results The CAI group exhibited greater ankle inversion angles from 14 to 48% of the stance phase (%SP) (p = 0.008), ankle eversion moments from 40 to 78%SP (p < 0.001), knee abduction moments from 3 to 6%SP and peroneus longus muscle activity from 0 to 15%SP (p = 0.003) and 60 to 76%SP (p = 0.003) compared to the control group. No significant between-group differences in ankle sagittal and transverse angles and moments, knee angles, knee sagittal and transverse moments as well as gluteus medius, vastus lateralis, gastrocnemius lateralis and tibialis anterior muscles activity were found. Conclusions During the first half of the stance phase, individuals with CAI could be at more risk of sustaining recurrent LAS mostly due to greater ankle inversion angles. However, the greater ankle eversion moments and peroneus longus muscle activity during the second half of the stance phase were an efficient mechanism to correct this maladaptive gait pattern and allowed to attenuate the faulty ankle movements during the pre-swing phase.

Repeated Kicking Actions in Karate: Effect on Technical Execution in Elite Practitioners

2016 ◽  
Vol 11 (3) ◽  
pp. 363-369 ◽  
Author(s):  
Federico Quinzi ◽  
Valentina Camomilla ◽  
Alberto Di Mario ◽  
Francesco Felici ◽  
Paola Sbriccoli
Keyword(s):  
Knee Flexion ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Linear Regression Analysis ◽  
Knee Kinematics ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Median Frequency ◽  
Flexion Extension ◽  
Hip Abduction

Purpose:Training in martial arts is commonly performed by repeating a technical action continuously for a given number of times. This study aimed to investigate if the repetition of the task alters the proper technical execution, limiting the training efficacy for the technical evaluation during competition. This aim was pursued analyzing lower-limb kinematics and muscle activation during repeated roundhouse kicks.Methods:Six junior karate practitioners performed continuously 20 repetitions of the kick. Hip and knee kinematics and sEMG of vastus lateralis, biceps (BF), and rectus femoris were recorded. For each repetition, hip abduction–adduction and flexion–extension and knee flexion–extension peak angular displacements and velocities, agonist and antagonist muscle activation were computed. Moreover, to monitor for the presence of myoelectric fatigue, if any, the median frequency of the sEMG was computed. All variables were normalized with respect to their individual maximum observed during the sequence of kicks. Linear regressions were fitted to each normalized parameter to test its relationship with the repetition number.Results:Linear-regression analysis showed that, during the sequence, the athletes modified their technique: Knee flexion, BF median frequency, hip abduction, knee-extension angular velocity, and BF antagonist activation significantly decreased. Conversely, hip flexion increased significantly.Conclusions:Since karate combat competitions require proper technical execution, training protocols combining severe fatigue and technical actions should be carefully proposed because of technique adaptations. Moreover, trainers and karate masters should consider including specific strength exercises for the BF and more generally for knee flexors.

Discipline and Sex Differences in Angle-specific Isokinetic Analysis in Elite Skiers

2019 ◽  
Vol 40 (05) ◽  
pp. 317-330 ◽  
Author(s):  
Marine Alhammoud ◽  
Baptiste Morel ◽  
Clint Hansen ◽  
Mathew Wilson ◽  
Regis Mecca ◽  
...  
Keyword(s):  
Statistical Parametric Mapping ◽  
Knee Extension ◽  
Current Data ◽  
Screening Methods ◽  
Full Extension ◽  
Isokinetic Testing ◽  
Parametric Mapping ◽  
National Team ◽  
Alpine Skiers ◽  
The Impact

AbstractStandard outcomes of traditional isokinetic testing do not detect differences between various muscle mechanical properties. This study i) explored a novel analysis throughout the range of motion based on statistical parametric mapping and ii) examined the impact of sex and discipline on hamstrings/quadriceps torque in elite alpine skiers. Twenty-eight national team skiers (14 females, 14 males; 14 technical, 14 speed) undertook an isokinetic evaluation of the knee flexors/extensors (range 30–90°, 0° representing full extension). There was no effect of sex (p=0.864, d=0.03) and discipline (p=0.360, d=0.17) on maximal hamstrings-to-quadriceps ratio and no effect of discipline on maximal torque (p>0.156, d≤0.25). Hamstrings torque and hamstrings-to-quadriceps ratio were lower in females than males toward knee extension only (p<0.05). Quadriceps torque was greater after 72° of knee flexion in technicians than downhill skiers (p<0.05). The current data showed that statistical parametric mapping analysis identified angle-specific differences that could not be evidenced when analyzing only maximal torques and reconstructed ratios. This may enhance screening methods to identify pathologic knee function or monitor rehabilitation programs, and inform sex- and discipline-specific training in alpine skiing.

scholarly journals Central excitability does not limit postfatigue voluntary activation of quadriceps femoris

2006 ◽  
Vol 100 (6) ◽  
pp. 1757-1764 ◽  
Author(s):  
J. M. Kalmar ◽  
E. Cafarelli
Keyword(s):  
Evoked Potentials ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Motor Evoked Potentials ◽  
Vastus Lateralis ◽  
Central Fatigue ◽  
Knee Extension ◽  
Voluntary Activation ◽  
Fatigue Protocol ◽  
Central Excitability

After fatigue, motor evoked potentials (MEP) elicited by transcranial magnetic stimulation and cervicomedullary evoked potentials elicited by stimulation of the corticospinal tract are depressed. These reductions in corticomotor excitability and corticospinal transmission are accompanied by voluntary activation failure, but this may not reflect a causal relationship. Our purpose was to determine whether a decline in central excitability contributes to central fatigue. We hypothesized that, if central excitability limits voluntary activation, then a caffeine-induced increase in central excitability should offset voluntary activation failure. In this repeated-measures study, eight men each attended two sessions. Baseline measures of knee extension torque, maximal voluntary activation, peripheral transmission, contractile properties, and central excitability were made before administration of caffeine (6 mg/kg) or placebo. The amplitude of vastus lateralis MEPs elicited during minimal muscle activation provided a measure of central excitability. After a 1-h rest, baseline measures were repeated before, during, and after a fatigue protocol that ended when maximal voluntary torque declined by 35% (Tlim). Increased prefatigue MEP amplitude ( P = 0.055) and cortically evoked twitch ( P < 0.05) in the caffeine trial indicate that the drug increased central excitability. In the caffeine trial, increased MEP amplitude was correlated with time to task failure ( r = 0.74, P < 0.05). Caffeine potentiated the MEP early in the fatigue protocol ( P < 0.05) and offset the 40% decline in placebo MEP ( P < 0.05) at Tlim. However, this was not associated with enhanced maximal voluntary activation during fatigue or recovery, demonstrating that voluntary activation is not limited by central excitability.

The effects of differences on sagittal kinematics and muscle coordination during step up and step down in patients with spinal stenosis

2021 ◽  
pp. 1-7
Author(s):  
Sun-Shil Shin ◽  
Won-Gyu Yoo
Keyword(s):  
Spinal Stenosis ◽  
Vastus Lateralis ◽  
Center Of Mass ◽  
Gluteus Medius ◽  
Muscle Coordination ◽  
Limb Muscle ◽  
Compensatory Mechanisms ◽  
Contraction Ratio ◽  
Trunk Posture ◽  
Step Down

BACKGROUND AND OBJECTIVE: Lumbar spinal stenosis (LSS) is a common spinal disorder that causes patients to assume a forward-trunk posture. Spinal alignment affects swing limb angles and stance limb muscle activities. Therefore, we investigated the effects of differences in step up (SU) and step down (SD) tasks on the kinematics of the trunk and swing limb as well as stance limb muscle coordination in patients with LSS. METHODS: Nine elderly female patients diagnosed with LSS were recruited for this study. The sagittal kinematics of the trunk and swing limb and isolated contraction ratio of the gluteus medius (GMed) and vastus lateralis (VL) during SU and SD tasks were measured using a motion analysis system and surface electromyography system. RESULTS: Thoracic (17.71∘± 7.77∘) and spine angles (13.64∘± 11.34∘) as well as swing hip (48.48 ± 12.76) and pelvic angles (7.52 ± 10.33) were significantly greater during SU than SD (10.14 ± 8.41, 10.03 ± 11.03, 29.42 ± 10.57, 3.21 ± 10.11, all P< 0.05, respectively). The isolated contraction ratio of the GMed of the stance limb (34.12% ± 13.28%) was significantly higher during SU than during SD (26.65% ± 10.02%), whereas that of the VL of the stance limb (65.88% ± 13.28%) was significantly lower during SU than during SD (73.35% ± 10.02%, P= 0.011 for both comparisons). CONCLUSIONS: Patients with LSS demonstrated trunk compensatory mechanisms to address swing hip and knee angles. Trunk position affected pelvic limb muscle coordination in the standing support limb. These findings demonstrate that SD are more challenging than SU for patients with LSS, possibly due to reduced ability to generate adequate leg extensor muscular output to safely control the motion of the body’s center of mass. Therefore, trunk positions must be considered when patients with LSS undergo rehabilitation programs, particularly those involving SD or descending stairs, so that healthcare professionals can better assist patients with LSS. In addition, this study provides a background for further studies.

scholarly journals Exploratory study of electromyographic behavior of the vastus medialis and vastus lateralis at neuromuscular fatigue onset

2014 ◽  
Vol 20 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Cristiano Rocha da Silva ◽  
Danilo de Oliveira Silva ◽  
Deisi Ferrari ◽  
Rúben de Faria Negrão Filho ◽  
Neri Alves ◽  
...  
Keyword(s):  
Exploratory Study ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Neuromuscular Fatigue ◽  
Isometric Contractions ◽  
Median Frequency ◽  
Vastus Medialis ◽  
Mean Square ◽  
Electromyographic Signal ◽  
The Moment

This study aimed to determine and analyze the neuromuscular fatigue onset by median frequency (MDF) and the root mean square (RMS) behavior of an electromyographic signal (EMG). Eighteen healthy men with no prior knee problems initially performed three maximum voluntary isometric contractions (MVIC). After two days of MVIC test, participants performed a fatiguing protocol in which they performed submaximal knee-extension contractions at 20% and 70% MVIC held to exhaustion. The MDF and RMS values from the EMG signals were recorded from the vastus medialis (VM) and the vastus lateralis (VL). Analysis of the MDF and RMS behavior enabled identification of neuromuscular fatigue onset for VM and VL muscles in 20% and 70% loads. Alterations between the VM and VL in the neuromuscular fatigue onset, at 20% and 70% MVIC, were not significant. These findings suggest that the methodology proposal was capable of indicating minute differences sensible to alterations in the EMG signals, allowing identification of the moment when the MDF and the RMS showed significant changes in behavior. The methodology used was also a viable one for describing and identifying the neuromuscular fatigue onset by means of the analysis of EMG signals.

Compensatory muscle fiber hypertrophy in elderly men

1992 ◽  
Vol 73 (3) ◽  
pp. 812-816 ◽  
Author(s):  
A. Aniansson ◽  
G. Grimby ◽  
M. Hedberg
Keyword(s):  
Muscle Strength ◽  
Muscle Fiber ◽  
Citrate Synthase ◽  
Biceps Brachii ◽  
Vastus Lateralis ◽  
Cell Mass ◽  
Knee Extension ◽  
Type I ◽  
Type Ii ◽  
Elderly Men

Muscle strength and muscle morphology have been studied three times during a period of 11 yr in nine elderly men. On the last occasion the average age was 80.4 (range 79–82) yr. Body cell mass decreased by 6% and muscle strength for knee extension, measured by means of isometric and concentric isokinetic (30–60 degrees/s) recordings, declined by 25–35% over the 11-yr period. Between 76 and 80 yr of age only the isokinetic strength for 30 degrees/s decreased significantly. Muscle fiber composition in the vastus lateralis did not change between 69 and 76 yr of age, but there was a significant reduction in the proportion of type IIb fibers from 76 to 80 yr. The decrease in type II fiber areas was not significant between 69 and 76 yr of age (as in a larger sample from the same population), but a significant increase in both type I and type II fiber areas was recorded from 76 to 80 yr of age and biceps brachii showed similar tendencies. In the same period, the enzymatic activities of myokinase and lactate dehydrogenase subsided in the vastus lateralis, but there was no change for triose phosphate dehydrogenase, 3-hydroxy-CoA-dehydrogenase, and citrate synthase. The muscle fiber hypertrophy in this group of elderly men with maintained physical activity between 76 and 80 yr of age is interpreted as a compensatory adaptation for the loss of motor units. In addition, the adaptation with respect to oxidative capacities seems to be maintained at this age.

scholarly journals Regional and muscle-specific adaptations in knee extensor hypertrophy using flywheel versus conventional weight-stack resistance exercise

2019 ◽  
Vol 44 (8) ◽  
pp. 827-833 ◽  
Author(s):  
Tommy R. Lundberg ◽  
Maria T. García-Gutiérrez ◽  
Mirko Mandić ◽  
Mats Lilja ◽  
Rodrigo Fernandez-Gonzalo
Keyword(s):  
Resistance Exercise ◽  
Muscle Hypertrophy ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Knee Extensors ◽  
Cross Sectional ◽  
Proximal Site ◽  
Before And After

This study compared the effects of the most frequently employed protocols of flywheel (FW) versus weight-stack (WS) resistance exercise (RE) on regional and muscle-specific adaptations of the knee extensors. Sixteen men (n = 8) and women (n = 8) performed 8 weeks (2–3 days/week) of knee extension RE employing FW technology on 1 leg (4 × 7 repetitions), while the contralateral leg performed regular WS training (4 × 8–12 repetitions). Maximal strength (1-repetition maximum (1RM) in WS) and peak FW power were determined before and after training for both legs. Partial muscle volume of vastus lateralis (VL), vastus medialis (VM), vastus intermedius (VI), and rectus femoris (RF) were measured using magnetic resonance imaging. Additionally, quadriceps cross-sectional area was assessed at a proximal and a distal site. There were no differences (P > 0.05) between FW versus WS in muscle hypertrophy of the quadriceps femoris (8% vs. 9%), VL (10% vs. 11%), VM (6% vs. 8%), VI (5% vs. 5%), or RF (17% vs. 17%). Muscle hypertrophy tended (P = 0.09) to be greater at the distal compared with the proximal site, but there was no interaction with exercise method. Increases in 1RM and FW peak power were similar across legs, yet the increase in 1RM was greater in men (31%) than in women (20%). These findings suggest that FW and WS training induces comparable muscle-specific hypertrophy of the knee extensors. Given that these robust muscular adaptations were brought about with markedly fewer repetitions in the FW compared with WS, it seems FW training can be recommended as a particularly time-efficient exercise paradigm.

scholarly journals Acute effect of tendon vibration applied during isometric contraction at two knee angles on maximal knee extension force production

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242324
Author(s):  
Jonathan Harnie ◽  
Thomas Cattagni ◽  
Christophe Cornu ◽  
Peter McNair ◽  
Marc Jubeau
Keyword(s):  
Isometric Contraction ◽  
Vastus Lateralis ◽  
Force Production ◽  
Knee Extensor ◽  
Acute Effect ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Tendon Vibration ◽  
Knee Angle

The aim of the current study was to investigate the effect of a single session of prolonged tendon vibration combined with low submaximal isometric contraction on maximal motor performance. Thirty-two young sedentary adults were assigned into two groups that differed based on the knee angle tested: 90° or 150° (180° = full knee extension). Participants performed two fatigue-inducing exercise protocols: one with three 10 min submaximal (10% of maximal voluntary contraction) knee extensor contractions and patellar tendon vibration (80 Hz) another with submaximal knee extensor contractions only. Before and after each fatigue protocol, maximal voluntary isometric contractions (MVC), voluntary activation level (assessed by the twitch interpolation technique), peak-to-peak amplitude of maximum compound action potentials of vastus medialis and vastus lateralis (assessed by electromyography with the use of electrical nerve stimulation), peak twitch amplitude and peak doublet force were measured. The knee extensor fatigue was significantly (P<0.05) greater in the 90° knee angle group (-20.6% MVC force, P<0.05) than the 150° knee angle group (-8.3% MVC force, P = 0.062). Both peripheral and central alterations could explain the reduction in MVC force at 90° knee angle. However, tendon vibration added to isometric contraction did not exacerbate the reduction in MVC force. These results clearly demonstrate that acute infrapatellar tendon vibration using a commercial apparatus operating at optimal conditions (i.e. contracted and stretched muscle) does not appear to induce knee extensor neuromuscular fatigue in young sedentary subjects.

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