scholarly journals Joint Torque and Mechanical Power of Lower Extremity and Its Relevance to Hamstring Strain during Sprint Running

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yunjian Zhong ◽  
Weijie Fu ◽  
Shutao Wei ◽  
Qing Li ◽  
Yu Liu
Keyword(s):  
Lower Extremity ◽  
Stance Phase ◽  
Swing Phase ◽  
Joint Torque ◽  
Mechanical Power ◽  
Movement Direction ◽  
Joint Torques ◽  
Sprint Running ◽  
Lower Extremity Muscle ◽  
Muscle Groups

The aim of this study was to quantify the contributions of lower extremity joint torques and the mechanical power of lower extremity muscle groups to further elucidate the loadings on hamstring and the mechanics of its injury. Eight national-level male sprinters performed maximum-velocity sprint running on a synthetic track. The 3D kinematic data and ground reaction force (GRF) were collected synchronously. Intersegmental dynamics approach was used to analyze the lower extremity joint torques and power changes in the lower extremity joint muscle groups. During sprinting, the GRF during the stance phase and the motion-dependent torques (MDT) during the swing phase had a major effect on the lower extremity movements and muscle groups. Specifically, during the stance phase, torque produced and work performed by the hip and knee muscles were generally used to counteract the GRF. During the swing phase, the role of the muscle torque changed to mainly counteract the effect of MDT to control the movement direction of the lower extremity. Meanwhile, during the initial stance and late swing phases, the passive torques, namely, the ground reaction torques and MDT produced by the GRF and the inertial movement of the segments of the lower extremity, applied greater stress to the hamstring muscles.

scholarly journals Walking With a Robotic Exoskeleton Does Not Mimic Natural Gait: A Within-Subjects Study (Preprint)

2018 ◽  
Author(s):  
Chad Swank ◽  
Sharon Wang-Price ◽  
Fan Gao ◽  
Sattam Almutairi
Keyword(s):  
Lower Extremity ◽  
Muscle Activity ◽  
Stance Phase ◽  
Swing Phase ◽  
Healthy Adults ◽  
Emg Activity ◽  
Robotic Exoskeleton ◽  
Gait Parameters ◽  
Muscle Groups ◽  
The Impact

BACKGROUND Robotic exoskeleton devices enable individuals with lower extremity weakness to stand up and walk over ground with full weight-bearing and reciprocal gait. Limited information is available on how a robotic exoskeleton affects gait characteristics. OBJECTIVE The purpose of this study was to examine whether wearing a robotic exoskeleton affects temporospatial parameters, kinematics, and muscle activity during gait. METHODS The study was completed by 15 healthy adults (mean age 26.2 [SD 8.3] years; 6 males, 9 females). Each participant performed walking under 2 conditions: with and without wearing a robotic exoskeleton (EKSO). A 10-camera motion analysis system synchronized with 6 force plates and a surface electromyography (EMG) system captured temporospatial and kinematic gait parameters and lower extremity muscle activity. For each condition, data for 5 walking trials were collected and included for analysis. RESULTS Differences were observed between the 2 conditions in temporospatial gait parameters of speed, stride length, and double-limb support time. When wearing EKSO, hip and ankle range of motion (ROM) were reduced and knee ROM increased during the stance phase. However, during the swing phase, knee and ankle ROM were reduced when wearing the exoskeleton bionic suit. When wearing EKSO, EMG activity decreased bilaterally in the stance phase for all muscle groups of the lower extremities and in the swing phase for the distal muscle groups (tibialis anterior and soleus) as well as the left medial hamstrings. CONCLUSIONS Wearing EKSO altered temporospatial gait parameters, lower extremity kinematics, and muscle activity during gait in healthy adults. EKSO appears to promote a type of gait that is disparate from normal gait in first-time users. More research is needed to determine the impact on gait training with EKSO in people with gait impairments.

Lower-Extremity Muscle Activity During Aquatic and Land Treadmill Running at the Same Speeds

2014 ◽  
Vol 23 (2) ◽  
pp. 107-122 ◽  
Author(s):  
W. Matthew Silvers ◽  
Eadric Bressel ◽  
D. Clark Dickin ◽  
Garry Killgore ◽  
Dennis G. Dolny
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Swing Phase ◽  
Treadmill Running ◽  
Vastus Medialis ◽  
Lower Extremity Muscle

Context:Muscle activation during aquatic treadmill (ATM) running has not been examined, despite similar investigations for other modes of aquatic locomotion and increased interest in ATM running.Objectives:The objectives of this study were to compare normalized (percentage of maximal voluntary contraction; %MVC), absolute duration (aDUR), and total (tACT) lower-extremity muscle activity during land treadmill (TM) and ATM running at the same speeds.Design:Exploratory, quasi-experimental, crossover design.Setting:Athletic training facility.Participants:12 healthy recreational runners (age = 25.8 ± 5 y, height = 178.4 ± 8.2 cm, mass = 71.5 ± 11.5 kg, running experience = 8.2 ± 5.3 y) volunteered for participation.Intervention:All participants performed TM and ATM running at 174.4, 201.2, and 228.0 m/min while surface electromyographic data were collected from the vastus medialis, rectus femoris, gastrocnemius, tibialis anterior, and biceps femoris.Main Outcome Measures:For each muscle, a 2 × 3 repeated-measures ANOVA was used to analyze the main effects and environment–speed interaction (P ≤ .05) of each dependent variable: %MVC, aDUR, and tACT.Results:Compared with TM, ATM elicited significantly reduced %MVC (−44.0%) but increased aDUR (+213.1%) and tACT (+41.9%) in the vastus medialis, increased %MVC (+48.7%) and aDUR (+128.1%) in the rectus femoris during swing phase, reduced %MVC (−26.9%) and tACT (−40.1%) in the gastrocnemius, increased aDUR (+33.1%) and tACT (+35.7%) in the tibialis anterior, and increased aDUR (+41.3%) and tACT (+29.2%) in the biceps femoris. At faster running speeds, there were significant increases in tibialis anterior %MVC (+8.6−15.2%) and tACT (+12.7−17.0%) and rectus femoris %MVC (12.1−26.6%; swing phase).Conclusion:No significant environment–speed interaction effects suggested that observed muscle-activity differences between ATM and TM were due to environmental variation, ie, buoyancy (presumed to decrease %MVC) and drag forces (presumed to increase aDUR and tACT) in the water.

scholarly journals Lower Extremity Motor Impairments in Ambulatory Chronic Hemiparetic Stroke: Evidence for Lower Extremity Weakness and Abnormal Muscle and Joint Torque Coupling Patterns

2017 ◽  
Vol 31 (9) ◽  
pp. 814-826 ◽  
Author(s):  
Natalia Sánchez ◽  
Ana Maria Acosta ◽  
Roberto Lopez-Rosado ◽  
Arno H. A. Stienen ◽  
Julius P. A. Dewald
Keyword(s):  
Lower Extremity ◽  
Degrees Of Freedom ◽  
Joint Torque ◽  
Motor Impairments ◽  
Lower Extremity Weakness ◽  
Joint Torques ◽  
Hemiparetic Stroke ◽  
Chronic Hemiparetic Stroke ◽  
Hip Extension ◽  
Flexion And Extension

Although global movement abnormalities in the lower extremity poststroke have been studied, the expression of specific motor impairments such as weakness and abnormal muscle and joint torque coupling patterns have received less attention. We characterized changes in strength, muscle coactivation and associated joint torque couples in the paretic and nonparetic extremity of 15 participants with chronic poststroke hemiparesis (age 59.6 ± 15.2 years) compared with 8 age-matched controls. Participants performed isometric maximum torques in hip abduction, adduction, flexion and extension, knee flexion and extension, ankle dorsi- and plantarflexion and submaximal torques in hip extension and ankle plantarflexion. Surface electromyograms (EMGs) of 10 lower extremity muscles were measured. Relative weakness (paretic extremity compared with the nonparetic extremity) was measured in poststroke participants. Differences in EMGs and joint torques associated with maximum voluntary torques were tested using linear mixed effects models. Results indicate significant poststroke torque weakness in all degrees of freedom except hip extension and adduction, adductor coactivation during extensor tasks, in addition to synergistic muscle coactivation patterns. This was more pronounced in the paretic extremity compared with the nonparetic extremity and with controls. Results also indicated significant interjoint torque couples during maximum and submaximal hip extension in both extremities of poststroke participants and in controls only during maximal hip extension. Additionally, significant interjoint torque couples were identified only in the paretic extremity during ankle plantarflexion. A better understanding of these motor impairments is expected to lead to more effective interventions for poststroke gait and posture.

Prediction of the Lower Extremity Muscle Forces During Stair Ascent and Descent

2008 ◽  
Author(s):  
Ali Selk Ghafari ◽  
Ali Meghdari ◽  
Gholam Reza Vossoughi
Keyword(s):  
Lower Extremity ◽  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Optimization Technique ◽  
The Elderly ◽  
Plantar Flexors ◽  
Stair Ascent ◽  
Lower Extremity Muscle ◽  
Anatomical Classification ◽  
Muscle Groups

An inverse dynamics musculoskeletal model of the lower extremity was combined with an optimization technique to estimate individual muscular forces and powers during stair ascent and descent. Eighteen Hill-type musculotendon actuators per leg were combined into the eleven functional muscle groups based on anatomical classification to drive the model in the sagittal plane. Simulation results illustrate the major functional differences in plantar flexors of the ankle and extensors of the knee and hip joints during ascent and descent. The results of this study not only could be employed to evaluate the rehabilitation results in the elderly but also could be used to design more anthropometric assistive devices with optimum power consumption.

scholarly journals Relationships between lower extremity strength and the multi-directional reach test in children aged 7 to 12 years

2019 ◽  
Vol 39 (02) ◽  
pp. 143-150
Author(s):  
Benjaporn Hirunyaphinun ◽  
Soontharee Taweetanalarp ◽  
Anong Tantisuwat
Keyword(s):  
Lower Extremity ◽  
Flexor Muscle ◽  
Limits Of Stability ◽  
Knee Flexor ◽  
Lower Extremity Muscle ◽  
Lower Extremity Strength ◽  
Flexor Muscles ◽  
Muscle Groups ◽  
Control Balance ◽  
Hip Flexor

Objective: This study investigates the relationships between the Multi-Directional Reach Test (MDRT) and lower extremity strength in typical children. Methods: The MDRT including forward, backward, leftward, and rightward directions was measured in 60 children aged between 7 and 12 years old with typical development. The lower extremity muscle groups were measured using a hand-held dynamometer. Results: The reaching score in each direction had positive relationships with the strengths of several lower extremity muscle groups ([Formula: see text] to [Formula: see text]). Only the strengths of the hip flexor and knee flexor muscles significantly correlated with the MDRT scores in all directions ([Formula: see text] to [Formula: see text]). Conclusion: This study highlights the strength of the hip and knee flexor muscle groups as being important domain to control balance in all directions. These findings may be used for therapists in planning a balance program to improve the limits of stability.

Kinematics and Kinetics of the Racket-Arm during the Soft-Tennis Smash under Match Conditions

2005 ◽  
Vol 21 (4) ◽  
pp. 334-347 ◽  
Author(s):  
Hirofumi Ida ◽  
Seiji Kusubori ◽  
Motonobu Ishii
Keyword(s):  
Time Pressure ◽  
Swing Phase ◽  
Joint Torque ◽  
Elbow Extension ◽  
Competitive Situation ◽  
Match Play ◽  
Joint Torques ◽  
Tennis Serve ◽  
Kinetics Of ◽  
Kinematics And Kinetics

The purposes of this study were to (a) describe the racket-arm kinematics and kinetics of the soft-tennis smash during match rallies, and (b) assess the characteristics of this smash vs. the laboratory-simulated smash of our previous study. In the current study we recorded soft-tennis smash motions during match play of the 3rd East Asian Games. Racket-arm anatomical joint angular velocity and anatomical joint torque were calculated from 3-D coordinate data of 13 collected motions obtained using the direct linear transformation procedure. The results showed that most of the maximum values of the anatomical joint torques were qualitatively smaller than those of the tennis serve. Peak elbow extension, shoulder internal rotation, and elbow varus torques in match play were significantly greater than values reported for laboratory-simulated conditions. The greater forward swing torques did not result in significantly different racket head velocity, possibly because there was a significantly shorter forward swing phase in match conditions. In particular, a clear peak of the elbow extension torque during the forward swing phase was the most characteristic pattern in the smashes under match conditions, for it was 160% greater than laboratory-simulated conditions. These results supported our hypothesis that racket-arm kinematic and kinetic characteristics of the smash under match conditions differ from those under laboratory-simulated conditions. Possible explanations include the time-pressure conditions of the competitive situation in a match, and the Hawthorne effect (Hudson et al., 1986), both of which alter performance between match conditions and laboratory-simulated conditions.

A Biomechanical Study of Side Steps at Different Distances

2013 ◽  
Vol 29 (3) ◽  
pp. 336-345 ◽  
Author(s):  
Yuki Inaba ◽  
Shinsuke Yoshioka ◽  
Yoshiaki Iida ◽  
Dean C. Hay ◽  
Senshi Fukashiro
Keyword(s):  
Inverse Dynamics ◽  
Center Of Mass ◽  
Reaction Force ◽  
Biomechanical Study ◽  
Joint Torque ◽  
Large Power ◽  
Lower Extremity Muscle ◽  
Ankle Joints ◽  
Hip Abduction ◽  
Muscle Groups

Lateral quickness is a crucial component of many sports. However, biomechanical factors that contribute to quickness in lateral movements have not been understood well. Thus, the purpose of this study was to quantify 3-dimensional kinetics of hip, knee, and ankle joints in side steps to understand the function of lower extremity muscle groups. Side steps at nine different distances were performed by nine male subjects. Kinematic and ground reaction force data were recorded, and net joint torque and work were calculated by a standard inverse-dynamics method. Extension torques and work done at hip, knee, and ankle joints contributed substantially to the changes in side step distances. On the other hand, hip abduction work was not as sensitive to the changes in the side step distances. The main roles of hip abduction torque and work were to accelerate the center of mass laterally in the earlier phase of the movement and to keep the trunk upright, but not to generate large power for propulsion.

THE ASSOCIATIONS BETWEEN KNEE FLEXION, VERTICAL CENTER-OF-MASS EXCURSIONS AND LOWER-EXTREMITY MUSCLE WORK FOR END-STAGE KNEE OSTEOARTHRITIS

2009 ◽  
Vol 12 (02) ◽  
pp. 77-84 ◽  
Author(s):  
David Mandeville ◽  
Louis R. Osternig ◽  
Li-Shan Chou
Keyword(s):  
Lower Extremity ◽  
Knee Osteoarthritis ◽  
Knee Flexion ◽  
Stance Phase ◽  
Center Of Mass ◽  
Osteoarthritis Of The Knee ◽  
Strong Positive Correlation ◽  
Muscle Work ◽  
Lower Extremity Muscle ◽  
End Stage

Purpose: The purpose of this study was to assess the association of the knee flexion excursion to the vertical center-of-mass (COM) amplitude and to the lower-extremity muscle work during stance phase for subjects with knee osteoarthritis. Method: Twenty subjects scheduled for total knee replacement and 20 controls performed level walking during standard gait analysis. Dependent variables included stance-phase knee flexion excursion, vertical COM amplitude, and lower-extremity muscle work. Results: Compared to healthy control, subjects with knee osteoarthritis walked with significantly less stance-phase knee flexion and vertical COM excursion. Knee flexion excursion was found to have a strong positive correlation to vertical COM amplitude. The lower-extremity muscle work during single stance phase was found to have a moderate negative correlation to vertical COM amplitude. Conclusions: Osteoarthritis of the knee alters both the stance-phase knee flexion and vertical COM excursions. As these variables show a strong positive relation, efforts to restore stance-phase knee flexion based on the 3rd determinant of gait require a new justification.

scholarly journals EFFECTS OF SPEED AND INCLINE ON LOWER EXTREMITY KINEMATICS DURING TREADMILL JOGGING IN HEALTHY SUBJECTS

2006 ◽  
Vol 18 (02) ◽  
pp. 73-79 ◽  
Author(s):  
LAN-YUEN GUO ◽  
FONG-CHIN SU ◽  
CHICH-HAUNG YANG ◽  
SHU-HUI WANG ◽  
JYH-JONG CHANG ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Motion Analysis ◽  
Repeated Measures ◽  
Stance Phase ◽  
Vision System ◽  
Movement Patterns ◽  
Swing Phase ◽  
Transverse Plane ◽  
Home Setting ◽  
Maximum Flexion

Recently, there are more people jogging with a treadmill at the gym or the home setting. The main available selected modes for treadmill jogging are speed and slope of incline. Increased speeds and incline slopes will not only increase the cardiopulmonary loading but may also alter the lower extremity (LE) movement patterns. There are few systematic investigations of the effect of the speed and incline on LE kinematics. Most studies have used 2D methods which focused on movements in sagittal plane only and this has limitations in the acquired data since lower extremity movements also include frontal and transverse planes. The current study aimed to investigate LE movement during jogging at different speeds and incline slopes using a high speed three-dimensional (3D) motion analysis system. Eighteen young healthy males were recruited. The video-based motion capture system with six CCD cameras, HIRES Expert Vision System (Motion Analysis Corporation, CA, USA), was used to collect kinematic data at a sampling frequency of 120Hz. Nineteen passive reflective markers were attached to bilateral lower extremities of the subject. The joint angle is calculated by Euler angle using the rotation sequence: 2-1-3 (y-x′-z″). Four speeds were selected: 2 m/s, 2.5 m/s, 3 m/s, 3.5 m/s with the slope at 0, and four slopes were selected: 0%, 5%,10%,15% at a speed of 3 m/s. Repeated-measures ANOVA was used to test hypotheses regarding changes in jogging condition on LE kinematic variables. The significance level was set at 0.05. As the jogging slope increased, the hip, knee and ankle demonstrated a significantly greater maximum flexion in swing phase (p<0.001), but the maximum extension angles in stance phase were relatively unchanged. Increased LE flexion during swing phase is important to ensure foot clearance with increased slope. For increased speed, the hip and ankle joints had significantly greater maximum joint extension angles during stance phase and the hip and knee joint had significantly larger maximum flexion angles in swing phase (p<0.001). Increased motion during swing phase account for a larger step length and increased motion during stance phase may facilitate the generation of power during forward propulsion as the jogging speed increased. As the slope and speed increased, LE movement patterns were changed in the transverse plane: the significantly increased (p<0.01) internal hip rotation at terminal stance, the increased toe-in of foot (p<0.001) during terminal stance phase and decreased (p<0.05) toe-out during swing phase. Increased hip motion in transverse plane could lengthen the stride distance and increase foot toe-in for providing a stable lever for push off to increase propulsion force as speed or slope is increased. By way of systematic 3D kinematic investigation of the LE in jogging, the results further elucidate the effect of changing speed and incline on LE joints movements. This information could provide guidelines for rehabilitation clinicians or coaches to select an appropriate training mode for jogging.

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