scholarly journals EMG Activity With Use of a Hands-Free Single Crutch vs a Knee Scooter

2021 ◽  
Vol 6 (4) ◽  
pp. 247301142110600
Author(s):  
Cuyler Dewar ◽  
Terry L. Grindstaff ◽  
Brooke Farmer ◽  
Morgan Sainsbury ◽  
Sam Gay ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Perceived Exertion ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Surface Emg ◽  
Ankle Injuries ◽  
Assistive Device ◽  
Emg Activity ◽  
Level Of Evidence

Background: Foot and ankle injuries frequently require a period of nonweightbearing, resulting in muscle atrophy. Our previous study compared a hands-free single crutch (HFSC) to standard axillary crutches and found increased muscle recruitment and intensity while using the HFSC. Knee scooters are another commonly prescribed nonweightbearing device. The purpose of this study is to examine the electromyographic (EMG) differences between an HFSC and knee scooter, in conjunction with device preference and perceived exertion. Methods: A randomized crossover study was performed using 30 noninjured young adults. Wireless surface EMG electrodes were placed on the belly of the rectus femoris (RF), vastus lateralis (VL), lateral gastrocnemius (LG), and gluteus maximus (GM). Participants then ambulated along a 20-m walking area while 15 seconds of the gait cycle was recorded across 3 conditions: walking with a knee scooter, an HFSC, and with no assistive device. Mean muscle activity and peak EMG activity were recorded for each ambulatory modality. Immediately following testing, patient exertion and device preference was recorded. Results: The RF, LG, and GM showed increased peak EMG activity percentage, and the LG showed increased mean muscle activity while using the HFSC compared with the knee scooter. When comparing the knee scooter and HFSC to walking, both showed increased muscle activity in the RF, VL, and LG but no difference in the GM. There was no statistical difference in participant preference, whereas the HFSC had a statistically significant higher perceived exertion than the knee scooter ( P < .001). Conclusion: In this group of young, healthy noninjured volunteers, the HFSC demonstrated increased peak EMG activity in most muscle groups tested compared with the knee scooter. Level of Evidence: Level II, prospective comparative study.

scholarly journals Comparison of Lower Extremity EMG Muscle Testing With Hands-Free Single Crutch vs Standard Axillary Crutches

2020 ◽  
Vol 5 (3) ◽  
pp. 247301142093987
Author(s):  
Cuyler Dewar ◽  
Kevin D. Martin
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Vastus Lateralis ◽  
Demographic Data ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Gait Pattern ◽  
Assistive Device ◽  
Maximum Voluntary Isometric Contraction ◽  
Muscle Testing

Background: In order to maintain nonweightbearing restrictions of the lower extremity, an assistive device must be utilized. Currently most devices require the restricted limb to be held in a static position while the contralateral extremity provides forward propulsion. Atrophy and disuse conditions ensue rapidly, slowing healing and prolonging recovery. A hands-free single crutch (HFSC) utilizes both lower extremities, potentially reducing atrophy. The purpose of this study was to examine the electromyographic (EMG) differences between an HFSC and standard axillary crutches (SAC). Methods: A prospective, crossover study was performed using 21 healthy volunteers from an active duty foot and ankle clinic. Demographic data were obtained and then subjects were fitted with an HFSC and SAC. Wireless surface EMG sensors were applied to the belly of the rectus femoris (RF), vastus lateralis (VL), lateral gastrocnemius (LG), and the gluteus maximus (GM) by a board-certified orthopedic surgeon. Subjects then ambulated at a self-selected velocity for 30 m while 15 seconds of the gait cycle were recorded for each device. Mean muscle activity and the maximum voluntary isometric contraction (MVIC) were recorded. Results: The RF, GM, and LG showed significantly increased levels of muscle activity while using the HFSC compared to SAC (respectively P = .05, P = .03, P = .03). The VL did not show significantly higher muscle activity while using the HFSC ( P = .051). The RF, GM, and VL showed statistically significant higher MVIC percentages while using the HFSC compared with SAC (respectively P = .005, P = .005, P = .013). The LG did not show significantly higher MVIC percentage while using the HFSC ( P = .076). Conclusion: The HFSC subjects demonstrated increased muscle recruitment and intensity while maintaining cyclic contractions consistent with bipedal gait pattern. SAC demonstrated less recruitment and intensity with an isometric pattern regardless of the phase of gait. Clinical Relevance: Muscle atrophy following lower extremity immobilization.

Muscle coordination in cycling: effect of surface incline and posture

1998 ◽  
Vol 85 (3) ◽  
pp. 927-934 ◽  
Author(s):  
Li Li ◽  
Graham E. Caldwell
Keyword(s):  
Lower Extremity ◽  
High Speed ◽  
Vastus Lateralis ◽  
Activity Patterns ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Knee Extensors ◽  
Emg Activity ◽  
Muscle Coordination

The purpose of the present study was to examine the neuromuscular modifications of cyclists to changes in grade and posture. Eight subjects were tested on a computerized ergometer under three conditions with the same work rate (250 W): pedaling on the level while seated, 8% uphill while seated, and 8% uphill while standing (ST). High-speed video was taken in conjunction with surface electromyography (EMG) of six lower extremity muscles. Results showed that rectus femoris, gluteus maximus (GM), and tibialis anterior had greater EMG magnitude in the ST condition. GM, rectus femoris, and the vastus lateralis demonstrated activity over a greater portion of the crank cycle in the ST condition. The muscle activities of gastrocnemius and biceps femoris did not exhibit profound differences among conditions. Overall, the change of cycling grade alone from 0 to 8% did not induce a significant change in neuromuscular coordination. However, the postural change from seated to ST pedaling at 8% uphill grade was accompanied by increased and/or prolonged muscle activity of hip and knee extensors. The observed EMG activity patterns were discussed with respect to lower extremity joint moments. Monoarticular extensor muscles (GM, vastus lateralis) demonstrated greater modifications in activity patterns with the change in posture compared with their biarticular counterparts. Furthermore, muscle coordination among antagonist pairs of mono- and biarticular muscles was altered in the ST condition; this finding provides support for the notion that muscles within these antagonist pairs have different functions.

EMG Activity of Six Muscles and VMO:VL Ratio Determination during a Maximal Squat Exercise

1995 ◽  
Vol 4 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Peter A. Schaub ◽  
Teddy W. Worrell
Keyword(s):  
Lower Extremity ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Emg Activity ◽  
Kinetic Chain ◽  
Maximal Voluntary Isometric Contraction ◽  
Knee Rehabilitation ◽  
Intraclass Correlations ◽  
Ratio Determination

During knee rehabilitation, squats are a commonly used closed kinetic chain exercise. We have been unable to locate data reporting electromyographic (EMG) activity of lower extremity musculature during maximal effort squats and the contribution of gastrocnemius and gluteus maximus muscles. Therefore, the purposes of this study were (a) to quantify EMG activity of selected lower extremity muscles during a maximal isometric squat and during a maximal voluntary isometric contraction (MVIC), and (b) to determine ratios between the vastus medialis oblique (VMO) and vastus lateralis (VL) during maximal isometric squat and MVIC testing. Twenty-three subjects participated in a single testing session. Results are as follows: intraclass correlations for MVIC testing and squat testing ranged from .60 to .80 and .70 to .90, respectively. Percentage MVIC during the squat was as follows: rectus femoris 40 ± 30%, VMO 90 ± 70%, VL 70 ±40%, hamstrings 10 ± 10%, gluteus maximus 20 ± 10%, and gastrocnemius 30 ± 20%. No statistical difference existed in VMO:VL ratios during MVIC or squat testing. We conclude that large variations in muscle recruitment patterns occur between individuals during isometric squats.

Mono- and Biarticular Muscle Activity during Jumping in Different Directions

2003 ◽  
Vol 19 (3) ◽  
pp. 205-222 ◽  
Author(s):  
Stephanie L. Jones ◽  
Graham E. Caldwell
Keyword(s):  
Muscle Activity ◽  
Vastus Lateralis ◽  
Activity Patterns ◽  
Center Of Mass ◽  
Reaction Force ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Jump Condition ◽  
Activity Level ◽  
Biarticular Muscle

This study examined the role of mono- and biarticular muscles in control of countermovement jumps (CMJ) in different directions. It was hypothesized that monoarticular muscles would demonstrate the same activity regardless of jump direction, based on previous studies which suggest their role is to generate energy to maximize center-of-mass (CM) velocity. In contrast, biarticular activity patterns were expected to change to control the direction of the ground reaction force (GRF) and CM velocity vectors. Twelve participants performed maximal CMJs in four directions: vertical, forward, intermediate forward, and backward. Electromyographical data from 4 monoarticular and 3 biarticular lower extremity muscles were analyzed with respect to segmental kinematics and kinetics during the jumps. The biarticular rectus femoris (RF), hamstrings (HA), and gastrocnemius all exhibited changes in activity magnitude and pattern as a function of jump angle. In particular, HA and RF demonstrated reciprocal trends, with HA activity increasing as jump angle changed from backward to forward, while RF activity was reduced in the forward jump condition. The vastus lateralis and gluteus maximus both demonstrated changes in activity patterns, although the former was the only monoarticular muscle to change activity level with jump direction. Mono- and biarticular muscle activities therefore did not fit with their hypothesized roles. CM and segmental kinematics suggest that jump direction was initiated early in the countermovement, and that in each jump direction the propulsion phase began from a different position with unique angular and linear momentum. Issues that dictated the muscle activity patterns in each jump direction were the early initiation of appropriate forward momentum, the transition from countermovement to propulsion, the control of individual segment rotations, the control of GRF location and direction, and the influence of the subsequent landing.

scholarly journals EFFECTS OF TRADITIONAL STRENGTH TRAINING AND OLYMPIC WEIGHTLIFTING IN HANDBALL PLAYERS

2019 ◽  
Vol 25 (3) ◽  
pp. 230-234
Author(s):  
Bárbara Slovak ◽  
Leandro Carvalho ◽  
Fernando Rodrigues ◽  
Paulo Costa Amaral ◽  
Deborah Duarte Palma ◽  
...  
Keyword(s):  
Strength Training ◽  
Vastus Lateralis ◽  
Vertical Jump ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Level Of Evidence ◽  
Jump Performance ◽  
Plyometric Exercise ◽  
Regular Training

ABSTRACT Introduction Olympic weightlifting has been adopted as an alternative to plyometric exercise. However, the effects of these exercises in young handball athletes is not known. Objective To compare the effect of Olympic weightlifting training with traditional strength training on jumping, squatting and acceleration performance in young handball athletes. Ten female handball athletes were evaluated. After six weeks of regular training, the athletes underwent eight weeks of training specifically designed for the survey, with equivalence of the total volume of training and differences in the means used. The evaluations were performed after six weeks of regular training (Baseline), after four weeks of traditional strength training and after four weeks of Olympic weightlifting. Vertical Jumps with and without movement of the arms, acceleration of 10 m, 20 m and 30 m, and 1RM in squatting were quantified. Results Increases (p<0.05) were observed in accelerations and squatting in the Olympic weightlifting and in squatting in the traditional strength training. Differences in coordination, time to activation of the gastrocnemius, vastus lateralis, rectus femoris, biceps femoris and gluteus maximus, peak force and power and rate of force development between the jumps and exercises used in the training are hypotheses to be considered for the different responses adaptations found in the jumps. Conclusion The Olympic weightlifting training resulted in an increase in accelerations and strength, but not in vertical jump performance in young handball athletes. Level of Evidence I; Prognostic Studies - Investigation of the Effect of a Patient Characteristic on Disease Outcome.

Muscle activation and blood flow do not explain the muscle length-dependent variation in quadriceps isometric endurance

2005 ◽  
Vol 98 (3) ◽  
pp. 810-816 ◽  
Author(s):  
R. D. Kooistra ◽  
C. J. de Ruiter ◽  
A. de Haan
Keyword(s):  
Blood Flow ◽  
Blood Supply ◽  
Vastus Lateralis ◽  
Muscle Length ◽  
Rectus Femoris ◽  
Surface Emg ◽  
Knee Extensors ◽  
Emg Activity ◽  
Central Activation ◽  
Full Occlusion

We investigated the role of central activation in muscle length-dependent endurance. Central activation ratio (CAR) and rectified surface electromyogram (EMG) were studied during fatigue of isometric contractions of the knee extensors at 30 and 90° knee angles (full extension = 0°). Subjects ( n = 8) were tested on a custom-built ergometer. Maximal voluntary isometric knee extension with supramaximal superimposed burst stimulation (three 100-μs pulses; 300 Hz) was performed to assess CAR and maximal torque capacity (MTC). Surface EMG signals were obtained from vastus lateralis and rectus femoris muscles. At each angle, intermittent (15 s on 6 s off) isometric exercise at 50% MTC with superimposed stimulation was performed to exhaustion. During the fatigue task, a sphygmomanometer cuff around the upper thigh ensured full occlusion (400 mmHg) of the blood supply to the knee extensors. At least 2 days separated fatigue tests. MTC was not different between knee angles (30°: 229.6 ± 39.3 N·m vs. 90°: 215.7 ± 13.2 N·m). Endurance times, however, were significantly longer ( P < 0.05) at 30 vs. 90° (87.8 ± 18.7 vs. 54.9 ± 12.1 s, respectively) despite the CAR not differing between angles at torque failure (30°: 0.95 ± 0.05 vs. 90°: 0.96 ± 0.03) and full occlusion of blood supply to the knee extensors. Furthermore, rectified surface EMG values of the vastus lateralis (normalized to prefatigue maximum) were also similar at torque failure (30°: 56.5 ± 12.5% vs. 90°: 58.3 ± 15.2%), whereas rectus femoris EMG activity was lower at 30° (44.3 ± 12.4%) vs. 90° (69.5 ± 25.3%). We conclude that differences in endurance at different knee angles do not find their origin in differences in central activation and blood flow but may be a consequence of muscle length-related differences in metabolic cost.

scholarly journals Magnetic Resonance Imaging Appearance of the Hip Musculature After Arthroscopic Labral-Level Iliopsoas Tenotomies

2017 ◽  
Vol 5 (5) ◽  
pp. 232596711770749 ◽  
Author(s):  
Brian E. Walczak ◽  
Donna G. Blankenbaker ◽  
Michael R. Tuite ◽  
James S. Keene
Keyword(s):  
Magnetic Resonance ◽  
Muscle Atrophy ◽  
Vastus Lateralis ◽  
Fatty Infiltration ◽  
Case Series ◽  
Psoas Muscle ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Low Grade ◽  
Level Of Evidence

Background: Iliopsoas (IP) muscle atrophy is a known consequence of open IP tenotomy, but the severity of IP muscle atrophy that occurs after arthroscopic labral-level IP tenotomies has not been documented. Purpose: To document the severity of muscle atrophy that occurs in the iliacus, psoas, and adjacent hip musculature after arthroscopic labral-level IP tenotomy. Study Design: Case series; Level of evidence, 4. Methods: Twenty-eight patients who had magnetic resonance arthrograms (MRAs) obtained prior to and 3 months to 5 years after arthroscopic labral-level IP tenotomies are the basis of this report. The pre- and postoperative MRAs of each patient were examined in consensus by 2 musculoskeletal radiologists who graded the postoperative muscle atrophy from 0 (no fatty infiltration) to 4 (>75% fatty infiltration) and noted any compensatory muscle hypertrophy or abnormal IP tendon morphology. Patients also were assessed with the Byrd 100-point modified Harris Hip Scoring system (MHHS) preoperatively and at the time of their postoperative MRA. Results: Postoperative MRAs were obtained on average 1.7 years (range, 3 months to 5 years) after hip arthroscopy. None of the patients had muscle atrophy on their preoperative MRAs. In contrast, 89% of patients had iliacus and psoas muscle atrophy on their postoperative MRAs, but only 2 (7%) developed grade 4 atrophy, and the majority (64%) had either grade 1 (n = 15) or no atrophy (n = 3). In addition, there were no significant differences in the MHHS of the patients with mild (grades 0-1), moderate (grades 2-3), or severe (grade 4) postoperative atrophy. Postoperative MRAs also demonstrated low-grade atrophy (grades 1-2) in the quadratus femoris (n = 5) and rectus femoris (n = 1) muscles, and 16 patients (57%) had distortion of the tendon, but none had a gap in their tendon. Conclusion: A majority of patients (89%) developed IP muscle atrophy after arthroscopic labral-level IP tenotomies, and although this percentage was similar (89% vs 90%) to that reported with lesser trochanteric IP tenotomies, the patients did not (1) develop atrophy of the gluteus maximus and vastus lateralis muscles, (2) have chronic IP tendon disruption, or (3) develop the severity of IP atrophy (55% grade 4 vs 7% grade 4) that has been reported after arthroscopic lesser trochanteric IP tenotomies.

Conception of Assistive Equipment for Rehabilitation of Patients with Spinal Cord Injury

2015 ◽  
Vol 23 ◽  
pp. 24-36
Author(s):  
Lap Nam Wong ◽  
Yue Zhen Hong ◽  
Jian Feng Sui ◽  
Rui Xu ◽  
Lin Hong Ji
Keyword(s):  
Spinal Cord ◽  
Lower Limb ◽  
Muscle Activity ◽  
Simulation Analysis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Assistive Device ◽  
Cord Injury ◽  
The Mean ◽  
The Right

Mobility is the urgent requisite of post spinal cord injury (SCI) patient. Since the alternative and compensatory approach is considered as the major function of mobility assistive device for post-SCI patients, the device should possess capability to acclimate to the ‘abnormal’ gait generate by the patients who usually undergo alternative and compensatory rehabilitation in their neural circuit. The functional ability of individual should be taking into account. Yet according to the requirement of neuro-protective treatment in post-SCI rehabilitation processing, locomotor-like activity is still an essential factor to patient. This study presents a novel concept and prototype of assistive technology base on foot control strategy to take an equilibrium between mobility and gait realization. To demonstrate that foot-induced over-ground locomotor assistive method is capable of achieving locomotor-like activity (dragging step), simulation analysis and prototype preliminary experiment have been conducted. Simulation analysis show that foot-induced assistance can allow more volitional activity compare to the hip-knee-induced assistive device. Yet the input and disturbance act on such kind of device may be increased. Surface electromyography (sEMG) from muscles of lower limb (right rectus femoris, right biceps femoris and right gluteus maximus) have been recorded during the preliminary experiment, and the mean of integrated EMG (iEMG) was used as evaluation of muscle activity. The result of the testing show that the mean of iEMG in the right gluteus maximus was reduced in the swing phase when the subject moving ahead with the prototype, but no significant change in the right rectus femoris. It may imply that foot-induced over-ground locomotor assistive device can reduce the muscle activity when patient complete locomotor-like movement and retain some amount of residual recruitment of lower limb, instead of substituting arbitrarily.

scholarly journals Muscle activation during single leg squat is affected by position of the nonstance limb

2021 ◽  
Author(s):  
Anne Khuu ◽  
Kari L. Loverro ◽  
Cara L. Lewis
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Gluteus Medius ◽  
Surface Emg ◽  
Knee Kinetics ◽  
Hip Muscles ◽  
Single Leg Squat ◽  
Ascent Phase

ABSTRACT Context: The single leg squat (SLS) is appropriate for targeting activation, strengthening, and/or neuromuscular retraining of the gluteus maximus, gluteus medius, and quadriceps. However, the effect of different non-stance leg positions on muscle activity has not been fully evaluated. Objective: To compare the muscle activity of selected stance leg hip muscles during the SLS with 3 non-stance leg positions: in front, in the middle, and in back. Design: Controlled laboratory study. Setting: Biomechanics laboratory. Participants: Seventeen healthy adults. Main Outcome Measure(s): Surface EMG data of the gluteus maximus, gluteus medius, lateral hamstrings, medial hamstrings, rectus femoris, and TFL as well as kinetic data of the hip and knee were collected while participants performed the 3 SLS tasks. Mean muscle activation levels during the descent phase and ascent phase for the selected hip muscles were compared for the 3 tasks. Hip and knee kinetics in all 3 planes were also compared for the 3 tasks. Each variable of interest was analyzed using a separate linear regression model with a generalized estimating equations correction. Results: Muscle activation levels of the gluteus maximus, gluteus medius, medial hamstrings, rectus femoris, and TFL on the stance leg during descent, and the medial hamstrings and TFL during ascent were significantly different between SLS tasks. The greatest number of differences occurred between SLS-Front and SLS-Back. During descent, gluteal muscle activity was greater in SLS-Front and SLS-Middle than in SLS-Back. For both phases, TFL activity was greater during SLS-Front than both SLS-Middle and SLS-Back. Kinetic differences at the hip and knee between SLS tasks were also observed. Conclusion: The 3 SLS tasks have different muscle activation and kinetic profiles. Clinician and researchers can vary non-stance leg position during the SLS to manipulate muscle activation levels and tailor the exercise to assist with goals at different stages of rehabilitation.

Electromyographic Analysis of Hip and Trunk Muscle Activity During Side Bridge Exercises in Subjects With Gluteus Medius Weakness

2020 ◽  
pp. 1-6
Author(s):  
Kyung-eun Lee ◽  
Seung-min Baik ◽  
Chung-hwi Yi ◽  
Oh-yun Kwon ◽  
Heon-seock Cynn
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
Knee Flexion ◽  
Gluteus Maximus ◽  
Random Order ◽  
Gluteus Medius ◽  
Surface Emg ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Abdominal Muscles

Context: Side bridge exercises strengthen the hip, trunk, and abdominal muscles and challenge the trunk muscles without the high lumbar compression associated with trunk extension or curls. Previous research using electromyography (EMG) reports that performance of the side bridge exercise highly activates the gluteus medius (Gmed). However, to the best of our knowledge, no previous research has investigated EMG amplitude in the hip and trunk muscles during side bridge exercise in subjects with Gmed weakness. Objective: The purpose of this study was to examine the EMG activity of the hip and trunk muscles during 3 variations of the side bridge exercise (side bridge, side bridge with knee flexion, and side bridge with knee flexion and hip abduction of the top leg) in subjects with Gmed weakness. Design: Repeated-measures experimental design. Setting: Research laboratory. Patients: Thirty subjects (15 females and 15 males) with Gmed weakness participated in this study. Intervention: Each subject performed 3 variations of the side bridge exercise in random order. Main Outcome Measures: Surface EMG was used to measure the muscle activities of the rectus abdominis, external oblique, longissimus thoracis, multifidus, Gmed, gluteus maximus, and tensor fasciae latae (TFL), and Gmed/TFL muscle activity ratio during 3 variations of the side bridge exercise. Results: There were significant differences in Gmed (F2,56 = 110.054, P < .001), gluteus maximus (F2,56 = 36.416, P < .001), and TFL (F2,56 = 108.342, P < .001) muscles among the 3 side bridge exercises. There were significant differences in the Gmed/TFL muscle ratio (F2,56 = 20.738, P < .001). Conclusion: Among 3 side bridge exercises, the side bridge with knee flexion may be effective for the individuals with Gmed weakness among 3 side bridge exercises to strengthen the gluteal muscles, considering the difficulty of the exercise and relative contribution of Gmed and TFL.

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