Influence of Hip Position on Electromyographic and Torque Productions in the Knee

1993 ◽  
Vol 2 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Scott J. Black ◽  
Michael L. Woodhouse ◽  
Stephen Suttmiller ◽  
Larry Shall
Keyword(s):  
Supine Position ◽  
Knee Flexion ◽  
Knee Extension ◽  
Emg Activity ◽  
Sitting Position ◽  
Surface Electrodes ◽  
Recreational Athletes ◽  
Emg Amplitude ◽  
Torque Values ◽  
Flexion And Extension

The effects of hip position on thigh electromyographic (EMG) activity and knee torque were evaluated. Twenty-four recreational athletes (12 males and 12 females) volunteered to participate. Subjects were tested isokinetically at 30°/s in sitting and supine positions both concentrically and eccentrically during knee flexion and extension. Gravity-corrected torques (N·m) were obtained for all tests. EMG amplitude (mV) was collected via surface electrodes. Torque values were significantly greater (p<.05) for knee flexion in the sitting position when compared to the supine. EMG activity did not change relative to hip position but typically increased (p<.05) during concentric trials. Knee extension torque and EMG activity did not change during sitting or supine positions. Results indicated that the sitting position had statistically significant advantages over the supine position for producing greater hamstring torque and maintaining similar levels of EMG output during isokinetic knee flexion.

Features of electromyographic changes in patients with upper limb lesions during various exercise types performance

2020 ◽  
Vol 96 (2) ◽  
pp. 54-58
Author(s):  
B.I. Vakhitov ◽  
I.S Raginov ◽  
I.H. Vakhitov ◽  
R.A. Bodrova ◽  
A.V. Izosimova
Keyword(s):  
Emg Activity ◽  
Healthy Individuals ◽  
Average Amplitude ◽  
Emg Amplitude ◽  
Physical Exercises ◽  
Clear Peak ◽  
Clinical Conditions ◽  
Low Amplitude ◽  
First Time ◽  
Flexion And Extension

For the first time in clinical conditions a study was carried out for estimation of average amplitude (AA-EMG) and frequency of oscillations repetitions parameters during dynamic and static exercises performance. We found that in healthy individuals EMG amplitude depends on the character of physical exercises performed. The largest EMG amplitude was registered when performing static exercises. It was found that in acute stroke patients, while performing flexion and extension of fingers, low-amplitude EMG activity was registered stretched for entire movement cycle without a clear peak of extremum. When performing static exercises, the amplitude and frequency of EMG oscillations changed significantly in a positive way.

scholarly journals Differences in the Flexion and Extension Phases during Kneeling Investigated by Kinematic and Contact Point Analyses: A Cross-sectional Study

2021 ◽  
Author(s):  
Yusuke Nakazoe ◽  
Akihiko Yonekura ◽  
Hiroyuki Takita ◽  
Takeshi Miyaji ◽  
Narihiro Okazaki ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Contact Point ◽  
Knee Extension ◽  
Cross Sectional Study ◽  
Extension Phase ◽  
3D Registration ◽  
Cross Sectional ◽  
Registration Method ◽  
Computed Tomography Images ◽  
Flexion And Extension

Abstract Background: Kneeling is necessary for certain religious and ceremonial occasions, crouching work, and gardening, which many people take part in worldwide. However, there have been few reports regarding kneeling activities. The purpose of this study was to clarify the kinematics of kneeling.Methods: The subjects were 15 healthy young males. Kneeling activity was analysed within a knee flexion angle from 100° to maximum flexion (maxflex, mean ± SD = 161.3 ± 3.2°). The kinematic and contact point (CP) analyses were performed using a 2D/3D registration method, in which a 3D bone model created from computed tomography images was matched to knee lateral fluoroscopic images and analysed on a personal computer.Results: In the kinematic analysis, the femur translated 37.5 mm posteriorly and rotated 19.8° externally relative to the tibia during the knee flexion phase. During the knee extension phase, the femur translated 36.4 mm anteriorly, which was almost the same amount as in the knee flexion phase. However, the femur rotated only 7.4° internally during the knee extension phase. In the CP analysis, the amount of anterior translation of the CP in the knee extension phase was greater in the medial CP and smaller in the lateral CP than that of posterior translation in the knee flexion phase.Conclusions: In kneeling, there was a difference in the rotational kinematics between the flexion phase and the extension phase. The kinematic difference between the flexion and extension phases may have some effect on the meniscus and articular cartilage.

Hip Adduction Does not Affect VMO EMG Amplitude or VMO:VL Ratios during a Dynamic Squat Exercise

2006 ◽  
Vol 15 (3) ◽  
pp. 195-205 ◽  
Author(s):  
Michelle Boling ◽  
Darin Padua ◽  
J. Troy Blackburn ◽  
Meredith Petschauer ◽  
Christopher Hirth
Keyword(s):  
Outcome Measures ◽  
Knee Flexion ◽  
Healthy Subjects ◽  
Vastus Lateralis ◽  
Test Session ◽  
Surface Emg ◽  
Knee Extension ◽  
Emg Amplitude ◽  
Squat Exercise ◽  
History Of

Context:Clinicians commonly attempt to facilitate vastus medialis oblique (VMO) activity by instructing patients to squeeze a ball between their knees during squatting exercises.Objective:To determine whether VMO activation amplitude and the VMO to vastus lateralis (VL) activation ratio (VMO:VL) were altered when performing active hip adduction during a dynamic squat exercise.Design:Single test session.Participants:Fifteen healthy subjects, with no history of knee pain, volunteered for this study.Intervention:Surface EMG of the VMO, VL, and hip adductor (ADD) muscles were recorded while subjects performed 10 consecutive squats against their body weight through a range of 0° to 90° of knee flexion. Subjects performed the squat exercises during two different conditions: (1) active hip adduction and (2) no hip adduction.Main Outcome Measures:Average VMO EMG amplitude and VMO:VL ratio were determined during the knee flexion (0° to 90°) and knee extension (90° to 0°) phases of the squat exercise.Results:Active hip adduction did not significantly change VMO amplitude or VMO:VL ratio during the knee flexion or knee extension phases of the dynamic squat exercise.Conclusions:Based on these results, we conclude that VMO amplitude and the VMO: VL ratio are not influenced by performing active hip adduction during a dynamic squat exercise in healthy subjects.

scholarly journals Examining Ankle-Joint Laxity Using 2 Knee Positions and With Simulated Muscle Guarding

2016 ◽  
Vol 51 (2) ◽  
pp. 111-117 ◽  
Author(s):  
Shawn Hanlon ◽  
Jaclyn Caccese ◽  
Christopher A. Knight ◽  
Charles “Buz” Swanik ◽  
Thomas W. Kaminski
Keyword(s):  
Knee Flexion ◽  
Emg Activity ◽  
Complex Motion ◽  
Cross Sectional ◽  
Anterior Drawer ◽  
Anterior Displacement ◽  
Emg Amplitude ◽  
Ankle Complex ◽  
Talar Tilt ◽  
The Individual

 Several factors affect the reliability of the anterior drawer and talar tilt tests, including the individual clinician's experience and skill, ankle and knee positioning, and muscle guarding.Context:  To compare gastrocnemius activity during the measurement of ankle-complex motion at different knee positions, and secondarily, to compare ankle-complex motion during a simulated trial of muscle guarding.Objectives:  Cross-sectional study.Design:  Research laboratory.Setting:  Thirty-three participants aged 20.2 ± 1.7 years were tested.Patients or Other Participants:  The ankle was loaded under 2 test conditions (relaxed, simulated muscle guarding) at 2 knee positions (0°, 90° of flexion) while gastrocnemius electromyography (EMG) activity was recorded.Intervention(s):  Anterior displacement (mm), inversion-eversion motion (°), and peak EMG amplitude values of the gastrocnemius (μV).Main Outcome Measure(s):  Anterior displacement did not differ between the positions of 0° and 90° of knee flexion (P = .193). Inversion-eversion motion was greater at 0° of knee flexion compared with 90° (P &lt; .001). Additionally, peak EMG amplitude of the gastrocnemius was not different between 0° and 90° of knee flexion during anterior displacement (P = .101). As expected, the simulated muscle-guarding trial reduced anterior displacement compared with the relaxed condition (0° of knee flexion, P = .008; 90° of knee flexion, P = .016) and reduced inversion-eversion motion (0° of knee flexion, P = .03; 90° of knee flexion, P &lt; .001).Results:  In a relaxed state, the gastrocnemius muscle did not appear to affect anterior ankle laxity at the 2 most common knee positions for anterior drawer testing; however, talar tilt testing may be best performed with the knee in 0° of knee flexion. Finally, our outcomes from the simulated muscle-guarding condition suggest that clinicians should use caution and be aware of reduced perceived laxity when performing these clinical examination techniques immediately postinjury.Conclusions:

Effect of Ankle Position on EMG Activity and Peak Torque of the Knee Extensors and Flexors during Isokinetic Testing

1997 ◽  
Vol 6 (4) ◽  
pp. 335-342 ◽  
Author(s):  
John P. Miller ◽  
Kerriann Catlaw ◽  
Robert Confessore
Keyword(s):  
Female Athletes ◽  
Peak Torque ◽  
Knee Extension ◽  
Knee Extensors ◽  
Emg Activity ◽  
Isokinetic Testing ◽  
Surface Electrodes ◽  
Activity Peak ◽  
Peak Knee ◽  
Healthy Female

The purpose of this study was to examine the effect of ankle position on the electromyographic (EMG) activity, peak torque, and peak knee flexion to extension torque ratio during isokinetic testing of the knee. Twelve healthy female athletes performed six maximal knee extension and flexion repetitions with their dominant legs at 60 and 180°/s with the ankle in a plantar flexed position and again in a dorsiflexed position. Root mean square EMG (rmsEMG) activity was determined by placing bipolar surface electrodes on the quadriceps and the hamstrings. Ankle position had no effect on the rmsEMG activity of the quadriceps or the hamstrings at either 60 or 180°/s. Significant differences were noted for peak flexor torque at 607s (p <.001) and 180°/s (p<.01) and for peak torque flexor/extensor ratio (p <.01), with higher values observed with ankle dorsiflexion. This suggests that ankle position affects knee flexor torque and flexor/extensor ratio but not hamstring activity during isokinetic testing of the knee.

scholarly journals Effects of Hip Flexion on Knee Extension and Flexion Isokinetic Angle-Specific Torques and HQ-Ratios

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Christian Baumgart ◽  
Eduard Kurz ◽  
Jürgen Freiwald ◽  
Matthias Wilhelm Hoppe
Keyword(s):  
Hip Joint ◽  
Knee Flexion ◽  
Daily Life ◽  
Knee Extension ◽  
Flexion Angle ◽  
Strength Testing ◽  
Knee Strength ◽  
Sporting Activities ◽  
Torque Values ◽  
Hip Flexion

Abstract Background and Methods During isokinetic knee strength testing, the knee flexion angles that correspond to the measured torque values are rarely considered. Additionally, the hip flexion angle during seated testing diverges from that in the majority of daily life and sporting activities. Limited information concerning the influence of hip angle, muscle contraction mode, and velocity on the isokinetic knee strength over the entire range of motion (ROM) is available. Twenty recreational athletes (10 females, 10 males; 23.3 ± 3.2 years; 72.1 ± 16.5 kg; 1.78 ± 0.07 m) were tested for isokinetic knee flexion and extension at 10° and 90° hip flexion with the following conditions: (i) concentric at 60°/s, (ii) concentric at 180°/s, and (iii) eccentric at 60°/s. The effects of hip angle, contraction mode, and velocity on angle-specific torques and HQ-ratios as well as conventional parameters (peak torques, angles at peak torque, and HQ-ratios) were analyzed using statistical parametric mapping and parametric ANOVAs, respectively. Results Generally, the angle-specific and conventional torques and HQ-ratios were lower in the extended hip compared to a flexed hip joint. Thereby, in comparison to the knee extension, the torque values decreased to a greater extent during knee flexion but not consistent over the entire ROM. The torque values were greater at the lower velocity and eccentric mode, but the influence of the velocity and contraction mode were lower at shorter and greater muscle lengths, respectively. Conclusions Isokinetic knee strength is influenced by the hip flexion angle. Therefore, a seated position during testing and training is questionable, because the hip joint is rarely flexed at 90° during daily life and sporting activities. Maximum knee strength is lower in supine position, which should be considered for training and testing. The angle-specific effects cannot be mirrored by the conventional parameters. Therefore, angle-specific analyses are recommended to obtain supplemental information and consequently to improve knee strength testing.

Effects of hip rotation on the electromyographic activity of the medial and lateral hamstrings and muscle force

2021 ◽  
pp. 1-7
Author(s):  
Wootaek Lim
Keyword(s):  
Prone Position ◽  
Supine Position ◽  
Knee Flexion ◽  
External Rotation ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Hamstring Muscles ◽  
Extension Force ◽  
Hip Rotation ◽  
Hip Extension

BACKGROUND: In clinical practice, knee flexion at the prone position for manual muscle testing of hamstrings and hip extension at the supine position for stretching of hamstring muscles are typically proposed. OBJECTIVE: Although different positions have been proposed for different purposes in hamstrings, the understanding of the changing the functional role of hamstrings with position changes is poorly understood. METHODS: The electromyographic (EMG) activity and hip extension force were compared among different postures; hip neutral, internal, and external rotation. EMG and force were measured in prone position during knee flexion and those were additionally measured in supine position during hip extension. In supine position, additional measurements were made in hip neutral, internal and external rotation. RESULTS: Hamstrings showed high EMG activity during knee flexion. Knee flexion force in prone position was significantly decreased at hip extension force in supine position. In supine position, EMG activity was significantly higher in semitendinosus (ST) than biceps femoris (BF) during internal rotation. CONCLUSIONS: It should be noted that bi-articular muscles may have different functional dependencies on the corresponding muscles for each joint. In addition, because the altered alignment of the hamstring muscles that was affected by hip rotation had a significant effect on muscle activity, and hip rotation may be helpful for selective training of medial or lateral hamstrings.

scholarly journals The foot abduction characteristics following Steenbeek foot abduction brace

2017 ◽  
Vol 25 (1) ◽  
pp. 230949901668408
Author(s):  
Anil Agarwal ◽  
Anubrat Kumar ◽  
Madhusudan Mishra
Keyword(s):  
Range Of Motion ◽  
Knee Flexion ◽  
External Rotation ◽  
Knee Extension ◽  
Tibial Rotation ◽  
Significant Component ◽  
Only Children ◽  
Knee Position ◽  
Hip Range Of Motion ◽  
Flexion And Extension

Purpose: We prospectively investigated the foot abduction characteristics following Steenbeek foot abduction brace (SFAB) use in corrected clubfeet. The foot abduction achievable in SFAB with knee flexion and extension was calculated to find the effectiveness and stretch exerted by it. Methods: Only children with corrected idiopathic clubfeet using SFAB for greater than 3 months were enrolled. The foot abduction with and without brace in knee extended and flexed positions was measured. Hip range of motion (ROM) with and without brace was also recorded. Results: The average age of 42 children ( 62 feet) was 24.25 months (range: 5–48 months). There was difference in foot abduction of 22.2° in knee extension and flexion with SFAB on. A significant change in foot stretch of 25.5° observed when the knee was moved from extended to flexed position indicated SFAB dynamicity. The SFAB was found to be an effective orthosis as it brought the corrected clubfoot into maximum abduction permissible in the foot during the phase of knee flexion. The tibial rotation accounted for a major component (61%) of apparent foot abduction with the brace on. A hip ROM of 52.2° was required for SFAB function. Conclusion: SFAB is a dynamic brace that functions better in flexed knee position. It is able to induce a near equivalent actual abduction available in the foot in flexed position of knee. There is a significant component of tibial external rotation in SFAB-induced foot abduction. SFAB function is also dependent on hip mechanics.

scholarly journals Heterogeneity of muscle activity during sedentary behavior

2016 ◽  
Vol 41 (11) ◽  
pp. 1155-1162 ◽  
Author(s):  
Arto J. Pesola ◽  
Arto Laukkanen ◽  
Olli Tikkanen ◽  
Taija Finni
Keyword(s):  
Health Risks ◽  
Muscle Activity ◽  
Knee Extension ◽  
Normal Weight ◽  
Emg Activity ◽  
Hamstring Muscle ◽  
Emg Amplitude ◽  
Isometric Knee Extension ◽  
The Individual ◽  
Muscle Inactivity

Replacing sitting by standing has been hypothesized to reduce the health risks of sitting, based on the assumption that muscles are passive during sitting and active during standing. Interventions have been more effective in overweight (OW) than in normal weight (NW) individuals, but subjects’ muscle activities have not been quantified. This study compared quadriceps and hamstring muscle electromyographic (EMG) activity between 57 NW (body mass index (BMI) 22.5 ± 1.5 kg/m2, female n = 36) and 27 OW (BMI 28.4 ± 2.9 kg/m2, female n = 8) subjects during non-fatiguing standing (15 s, EMGstanding) and sitting (30 min). EMG amplitude was normalized to EMG measured during maximal isometric knee extension and flexion (% EMGMVC), and sitting muscle inactivity and bursts were determined using 4 thresholds (60% or 90% EMGstanding and 1% or 2% EMGMVC). Comparisons were adjusted for sex, age, knee extension strength, and the individual threshold. Standing EMG amplitude was 36% higher in OW (1.9% ± 1.5% EMGMVC) than in NW (1.4% ± 1.4% EMGMVC, P < 0.05) subjects. During sitting, muscles were inactive 89.8% ± 12.7% of the measurement time with 12.7 ± 14.2 bursts/min across all thresholds. On average, 6% more activity was recorded in NW than in OW individuals for 3 of the 4 thresholds (P < 0.05 for 60% or 90% EMGstanding and 1% EMGMVC). In conclusion, the OW group had higher muscle activity amplitude during standing but more muscle inactivity during sitting for 3/4 of the thresholds tested. Interventions should test whether the observed heterogeneity in muscle activity affects the potential to gain cardiometabolic benefits from replacing sitting with standing.

The Supplemental Benefits of Strength Training for Aerobically Active Postmenopausal Women

1995 ◽  
Vol 3 (4) ◽  
pp. 332-339 ◽  
Author(s):  
Amy L. Morgan ◽  
Jody D. Ellison ◽  
Margaret P. Chandler ◽  
Wojtek J. Ckodzko-Zajko
Keyword(s):  
Resistance Training ◽  
Strength Training ◽  
Aerobic Exercise ◽  
Postmenopausal Women ◽  
Knee Flexion ◽  
Knee Extension ◽  
Older Individuals ◽  
Repetition Maximum ◽  
Experimental Group ◽  
Flexion And Extension

This study examined the supplemental benefits of strength training in aerobically active postmenopausal women. Eighteen women (61-71 yrs) who had been participating in regular aerobic exercise for the preceding 8 months were randomly assigned to control (n= 9) and experimental (n= 9) groups. Both groups continued aerobic exercise 3 times a week for the 8-week training period. In addition, the experimental group performed 3 sets (8–12 repetitions) of standard knee extension and flexion exercises at 80% of their 1-repetition maximum (1-RM). In the experimental group, highly significant increases in knee flexion and extension strength were observed. No changes in strength were noted in the control subjects. There were no significant changes in body composition for either group. The data suggest that aerobically active older individuals can greatly increase strength with resistance training, which is consistent with recent recommendations that resistance training should be used to supplement aerobic exercise.

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