MYOELECTRIC ACTIVATION DIFFERENCES IN TRANSFEMORAL AMPUTEES DURING LOCOMOTOR STATE TRANSITIONS

2016 ◽  
Vol 28 (06) ◽  
pp. 1650041 ◽  
Author(s):  
Bryson H. Nakamura ◽  
Michael E. Hahn
Keyword(s):  
Muscle Activation ◽  
Vastus Lateralis ◽  
Statistical Parametric Mapping ◽  
State Transitions ◽  
Prosthetic Devices ◽  
Lower Extremity Muscle ◽  
Transfemoral Amputees ◽  
Recruitment Patterns ◽  
The Individual

Locomotor state transitions are challenging for transfemoral (TF) amputees due to the lack of active knee control even in the current powered prosthetic devices. Myoelectric activation has been used successfully to classify steady-state locomotion states, but classification of transitions between locomotion states remains a challenge, especially for TF amputees. The purpose of this study was to determine if lower-extremity muscle activation differences between pre-transition and transition gait cycles occur in the involved or uninvolved limb of TF amputees during locomotion state transitions. Surface electromyography (EMG) was collected from residual muscles on the involved limb and from the uninvolved limb from five TF amputees as they transitioned between different locomotion states (level ground, ramp ascent/descent, stair ascent/descent). Statistical parametric mapping (SPM) was used to assess differences in activation. When analyzed as a group, the only significant differences were observed in the vastus lateralis of the uninvolved limb. High inter-subject variation reduced the significance of other pattern differences. Further inspection revealed that the individual subjects expressed three different recruitment patterns. These recruitment patterns may indicate compensatory strategies adopted by the subjects over the years since amputation. Furthermore, the separate recruitment patterns suggest the need for individualized locomotion transition classification algorithms rather than a general classification scheme.

scholarly journals Concurrent surface electromyography and force myography classification during times of prosthetic socket shift and user fatigue

2017 ◽  
Vol 4 ◽  
pp. 205566831770873 ◽  
Author(s):  
Joe Sanford ◽  
Rita Patterson ◽  
Dan O Popa
Keyword(s):  
Surface Electromyography ◽  
Muscle Activation ◽  
Surface Emg ◽  
Training Data ◽  
Control Input ◽  
Prosthetic Devices ◽  
Prosthetic Socket ◽  
User Fatigue ◽  
Force Myography

Objective Surface electromyography has been a long-standing source of signals for control of powered prosthetic devices. By contrast, force myography is a more recent alternative to surface electromyography that has the potential to enhance reliability and avoid operational challenges of surface electromyography during use. In this paper, we report on experiments conducted to assess improvements in classification of surface electromyography signals through the addition of collocated force myography consisting of piezo-resistive sensors. Methods Force sensors detect intrasocket pressure changes upon muscle activation due to changes in muscle volume during activities of daily living. A heterogeneous sensor configuration with four surface electromyography–force myography pairs was investigated as a control input for a powered upper limb prosthetic. Training of two different multilevel neural perceptron networks was employed during classification and trained on data gathered during experiments simulating socket shift and muscle fatigue. Results Results indicate that intrasocket pressure data used in conjunction with surface EMG data can improve classification of human intent and control of a powered prosthetic device compared to traditional, surface electromyography only systems. Significance Additional sensors lead to significantly better signal classification during times of user fatigue, poor socket fit, as well as radial and ulnar wrist deviation. Results from experimentally obtained training data sets are presented.

Altering muscle activity in the lower extremities by bipedal landing with different drop tasks and shoes

2021 ◽  
pp. 1-11
Author(s):  
Yang Yang ◽  
Changxiao Yu ◽  
Chenhao Yang ◽  
Liqin Deng ◽  
Weijie Fu
Keyword(s):  
Lower Extremity ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Movement Control ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
The Body ◽  
Basketball Players ◽  
Lower Extremity Muscle ◽  
Body Tissues

BACKGROUND: The ability of the lower-extremity muscle activation directly affects the performance and in turn interacts with the loading conditions of the muscle itself. However, systematic information concerning the characteristics of lower-extremity muscle during landings is lacking. In particular, the landing height and shoes are also important factors based on the actual situation, which could further contribute to understanding the neuromuscular activity and how biochemical response of the body tissues to double-leg drop landings. OBJECTIVE: The study was to investigate the effects of landing tasks on the activation of lower-extremity muscles and explore the relationship among movement control, landing heights, shoe cushioning, and muscle activities. METHODS: Twelve male basketball players were recruited to perform drop jump (DJ) and passive landing (PL) from three heights (30, 45, and 60 cm) while wearing highly-cushioned basketball shoes (HC) and less-cushioned control shoes (LC). EMG electrodes were used to record the activities of the target muscles (rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, and lateral gastrocnemius) during the landing tasks. RESULTS: Pre- and post-activation activity of the lower-extremity muscles significantly decreased during PL compared with those during DJ (p< 0.05). No significant shoe effects on the characteristics of muscle activation and coactivation during DJ movements were observed. However, the participants wearing LC showed significantly higher muscle post-activation (p< 0.05) at the three drop heights during PL compared with those wearing HC. Coactivation of the ankle muscles was higher in LC than in HC during 30-cm PL (p< 0.05). CONCLUSIONS: The activation patterns of lower-extremity muscles can be significantly influenced by landing types. Highly-cushioned basketball shoes would help reduce the risk of injuries by appropriately tuning the muscles during the PL.

scholarly journals The Effects of Whole Body Vibration Treatments on Lower Body Muscular Activity in Well-Trained Athletes from Different Sports Branches

2018 ◽  
Vol 6 (9a) ◽  
pp. 43
Author(s):  
İlbilge Özsu ◽  
Hayri Ertan ◽  
Deniz Şimşek ◽  
Bahtiyar Özçaldiran ◽  
Cem Kurt
Keyword(s):  
Lower Extremity ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Whole Body Vibration ◽  
Soccer Players ◽  
Whole Body ◽  
Basketball Players ◽  
Body Vibration ◽  
Lower Extremity Muscle ◽  
40 Hz

A limited number of acute whole body vibration (WBV) studies have investigated the effects of WBV treatments which were applied with different vibration frequencies and amplitude combinations on lower extremity muscle activation of well-trained athletes from different sports branches. To compare the effects of WBV on lower extremity muscle activation via Surface Electromyography (sEMG) of well-trained athletes from different sports branches (soccer, basketball and swimming) during static and dynamic squat exercises. sEMG activities of Tibialis Anterior (TA), Gastrocnemius Medialis (GM), Vastus Medialis (VM), Rectus Femoris (RF), Vastus Lateralis (VL) and Biceps Femoris (BF) muscles of 7 male soccer players, 7 male basketball players, and 6 male swimmers were recorded during WBV applied in static squat and dynamic squat positions with different frequencies (30-35-40 Hz) and amplitude (2-4 mm) combinations separated from each other by 5 min passive rest periods. Each combination was applied for 30 sec. The highest muscle activation was determined in TA of the swimmers compared to soccer players during static squat with 4mm-30Hz WBV application (p=0.027). The lowest muscle activation was also determined in VL of the swimmers compared to soccer players during static squat with 2mm-40Hz WBV (p=0.049). During dynamic squat with 4mm-40Hz WBV, the highest muscle activity was determined in RF of the basketball players compared to swimmers (p=0.030). However, dynamic squat with 2mm-40Hz WBV application gave rise to the lowest muscle activation in VL of the basketball players compared to soccer players (p=0.042). Well-trained athletes from different sports branches demonstrated different neuromuscular responses to acute WBV treatments. WBV during dynamic squatting which was applied with 4mm-40 Hz may be more beneficial in enhancing neuromuscular performance acutely for well-trained male athletes since it resulted in higher levels of muscular activation responses according to the present study.

The Influence of Ambulatory Aid on Lower-Extremity Muscle Activation During Gait

2018 ◽  
Vol 27 (3) ◽  
pp. 230-236 ◽  
Author(s):  
Michael Sanders ◽  
Anton E. Bowden ◽  
Spencer Baker ◽  
Ryan Jensen ◽  
McKenzie Nichols ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Ankle Injuries ◽  
The Novel ◽  
Foot And Ankle ◽  
Leg Muscles ◽  
Lower Extremity Muscle

Context: Foot and ankle injuries are common and often require a nonweight-bearing period of immobilization for the involved leg. This nonweight-bearing period usually results in muscle atrophy for the involved leg. There is a dearth of objective data describing muscle activation for different ambulatory aids that are used during the aforementioned nonweight-bearing period. Objective: To compare activation amplitudes for 4 leg muscles during (1) able-bodied gait and (2) ambulation involving 3 different ambulatory aids that can be used during the acute phase of foot and ankle injury care. Design: Within-subject, repeated measures. Setting: University biomechanics laboratory. Participants: Sixteen able-bodied individuals (7 females and 9 males). Intervention: Each participant performed able-bodied gait and ambulation using 3 different ambulatory aids (traditional axillary crutches, knee scooter, and a novel lower-leg prosthesis). Main Outcome Measure: Muscle activation amplitude quantified via mean surface electromyography amplitude throughout the stance phase of ambulation. Results: Numerous statistical differences (P < .05) existed for muscle activation amplitude between the 4 observed muscles, 3 ambulatory aids, and able-bodied gait. For the involved leg, comparing the 3 ambulatory aids: (1) knee scooter ambulation resulted in the greatest vastus lateralis activation, (2) ambulation using the novel prosthesis and traditional crutches resulted in greater biceps femoris activation than knee scooter ambulation, and (3) ambulation using the novel prosthesis resulted in the greatest gastrocnemius activation (P < .05). Generally speaking, muscle activation amplitudes were most similar to able-bodied gait when subjects were ambulating using the knee scooter or novel prosthesis. Conclusions: Type of ambulatory aid influences muscle activation amplitude. Traditional axillary crutches appear to be less likely to mitigate muscle atrophy during the nonweighting, immobilization period that often follows foot or ankle injuries. Researchers and clinicians should consider these results when recommending ambulatory aids for foot or ankle injuries.

Lower-Extremity Muscle Activation during the Star Excursion Balance Tests

2001 ◽  
Vol 10 (2) ◽  
pp. 93-104 ◽  
Author(s):  
Jennifer Erin Earl ◽  
Jay Hertel
Keyword(s):  
Lower Extremity ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Emg Activity ◽  
Muscle Activation Patterns ◽  
Lower Extremity Muscle ◽  
Balance Tests ◽  
Integrated Emg

Objective:To identify integrated EMG (I-EMG) activity of 6 lower-extremity muscles during the 8 Star Excursion Balance Tests (SEBTs).Design and Setting:Repeated measures, laboratory setting.Subjects:10 healthy young adults.Interventions:The SEBTs require the subject to balance on the stance leg and maximally reach with the contralateral foot along each of 8 lines extending from a common axis at 45° intervals.Measures:I-EMG activity of the vastus medialis obliquus (VMO), vastus lateralis (VL), medial hamstring (MH), biceps femoris (BF), anterior tibialis (AT), and gas-trocnemius.Results:Significant differences were found in all muscles (P < .05) except the gastrocnemius (P = .08). VMO and VL activity tended to be greatest with anteriorly directed excursions, whereas the MH and BF activity were greatest with posteriorly directed excursions. AT activity was lowest with the lateral excursion.Conclusions:Performance of the different SEBTs results in different lower-extremity muscle-activation patterns.

scholarly journals Muscle Activation During Side-Step Cutting Maneuvers in Male and Female Soccer Athletes

2008 ◽  
Vol 43 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Ashley M. Hanson ◽  
Darin A. Padua ◽  
J. Troy Blackburn ◽  
William E. Prentice ◽  
Christopher J. Hirth
Keyword(s):  
Sex Differences ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Gluteus Medius ◽  
Acl Injury ◽  
Division I ◽  
Electromyographic Activity ◽  
Male And Female ◽  
Lower Extremity Muscle

Abstract Context: Female soccer athletes are at greater risk of anterior cruciate ligament (ACL) injury than males. Sex differences in muscle activation may contribute to the increased incidence of ACL injuries in female soccer athletes. Objective: To examine sex differences in lower extremity muscle activation between male and female soccer athletes at the National Collegiate Athletic Association Division I level during 2 side-step cutting maneuvers. Design: Cross-sectional with 1 between-subjects factor (sex) and 2 within-subjects factors (cutting task and phase of contact). Setting: Sports medicine research laboratory. Patients or Other Participants: Twenty males (age = 19.4 ± 1.4 years, height = 176.5 ± 5.5 cm, mass = 74.6 ± 6.0 kg) and 20 females (age = 19.8 ± 1.1 years, height = 165.7 ± 4.3 cm, mass = 62.2 ± 7.2 kg). Intervention(s): In a single testing session, participants performed the running-approach side-step cut and the box-jump side-step cut tasks. Main Outcome Measure(s): Surface electromyographic activity of the rectus femoris, vastus lateralis, medial hamstrings, lateral hamstrings, gluteus medius, and gluteus maximus was recorded for each subject. Separate mixed-model, repeated-measures analysis of variance tests were used to compare the dependent variables across sex during the preparatory and loading contact phases of each cutting task. Results: Females displayed greater vastus lateralis activity and quadriceps to hamstrings coactivation ratios during the preparatory and loading phases, as well as greater gluteus medius activation during the preparatory phase only. No significant differences were noted between the sexes for muscle activation in the other muscles analyzed during each task. Conclusions: The quadriceps-dominant muscle activation pattern observed in recreationally active females is also present in female soccer athletes at the Division I level when compared with similarly trained male soccer athletes. The relationship between increased quadriceps activation and greater incidence of noncontact ACL injury in female soccer athletes versus males requires further study.

Phonetic iconicity in the evaluative morphology of a sample of Indo-European, Niger-Congo and Austronesian languages

2010 ◽  
Vol 3 (2) ◽  
pp. 156-180 ◽  
Author(s):  
Renáta Gregová ◽  
Lívia Körtvélyessy ◽  
Július Zimmermann
Keyword(s):  
Three Dimensional ◽  
Sound Symbolism ◽  
Three Dimensional Model ◽  
Austronesian Languages ◽  
Place Of Articulation ◽  
European Languages ◽  
Phonetic Symbolism ◽  
The Individual ◽  
Core Vocabulary

Universals Archive (Universal #1926) indicates a universal tendency for sound symbolism in reference to the expression of diminutives and augmentatives. The research ( Štekauer et al. 2009 ) carried out on European languages has not proved the tendency at all. Therefore, our research was extended to cover three language families – Indo-European, Niger-Congo and Austronesian. A three-step analysis examining different aspects of phonetic symbolism was carried out on a core vocabulary of 35 lexical items. A research sample was selected out of 60 languages. The evaluative markers were analyzed according to both phonetic classification of vowels and consonants and Ultan's and Niewenhuis' conclusions on the dominance of palatal and post-alveolar consonants in diminutive markers. Finally, the data obtained in our sample languages was evaluated by means of a three-dimensional model illustrating the place of articulation of the individual segments.

scholarly journals Role of Occupational Footwear and Prolonged Walking on Lower Extremity Muscle Activation during Maximal Exertions and Postural Stability Tasks

Biomechanics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 202-213
Author(s):  
Harish Chander ◽  
Sachini N. K. Kodithuwakku Arachchige ◽  
Alana J. Turner ◽  
Reuben F. Burch V ◽  
Adam C. Knight ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Postural Stability ◽  
Muscle Activation ◽  
Medial Gastrocnemius ◽  
Lower Extremity Muscle ◽  
Prolonged Duration ◽  
The Mean ◽  
The Impact

Background: Occupational footwear and a prolonged duration of walking have been previously reported to play a role in maintaining postural stability. The purpose of this paper was to analyze the impact of three types of occupational footwear: the steel-toed work boot (ST), the tactical work boot (TB), and the low-top work shoe (LT) on previously unreported lower extremity muscle activity during postural stability tasks. Methods: Electromyography (EMG) muscle activity was measured from four lower extremity muscles (vastus medialis (VM), medial hamstrings (MH), tibialis anterior (TA), and medial gastrocnemius (MG) during maximal voluntary isometric contractions (MVIC) and during a sensory organization test (SOT) every 30 min over a 4 h simulated workload while wearing ST, TB, and LT footwear. The mean MVIC and the mean and percentage MVIC during each SOT condition from each muscle was analyzed individually using a repeated measures ANOVA at an alpha level of 0.05. Results: Significant differences (p < 0.05) were found for maximal exertions, but this was limited to only the time main effect. No significant differences existed for EMG measures during the SOT. Conclusion: The findings suggest that occupational footwear type does not influence lower extremity muscle activity during both MVIC and SOT. Significantly lower muscle activity during maximal exertions over the course of the 4 h workload was evident, which can be attributed to localized muscular fatigue, but this was not sufficient to impact muscle activity during postural stability tasks.

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