scholarly journals Comparison of Joint Kinematics in Transition Running and Isolated Running in Elite Triathletes in Overground Conditions

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4869
Author(s):  
Laura Fraeulin ◽  
Christian Maurer-Grubinger ◽  
Fabian Holzgreve ◽  
David A. Groneberg ◽  
Daniela Ohlendorf
Keyword(s):  
Knee Flexion ◽  
Statistical Parametric Mapping ◽  
Step Length ◽  
Joint Kinematics ◽  
Inertial Motion ◽  
Long Distance ◽  
Kinematic Data ◽  
Warm Up ◽  
Hip Flexion ◽  
Hip Rotation

Triathletes often experience incoordination at the start of a transition run (TR); this is possibly reflected by altered joint kinematics. In this study, the first 20 steps of a run after a warm-up run (WR) and TR (following a 90 min cycling session) of 16 elite, male, long-distance triathletes (31.3 ± 5.4 years old) were compared. Measurements were executed on the competition course of the Ironman Frankfurt in Germany. Pacing and slipstream were provided by a cyclist in front of the runner. Kinematic data of the trunk and leg joints, step length, and step rate were obtained using the MVN Link inertial motion capture system by Xsens. Statistical parametric mapping was used to compare the active leg (AL) and passive leg (PL) phases of the WR and TR. In the TR, more spinal extension (~0.5–1°; p = 0.001) and rotation (~0.2–0.5°; p = 0.001–0.004), increases in hip flexion (~3°; ~65% AL−~55% PL; p = 0.001–0.004), internal hip rotation (~2.5°; AL + ~0–30% PL; p = 0.001–0.024), more knee adduction (~1°; ~80–95% AL; p = 0.001), and complex altered knee flexion patterns (~2–4°; AL + PL; p = 0.001–0.01) occurred. Complex kinematic differences between a WR and a TR were detected. This contributes to a better understanding of the incoordination in transition running.

scholarly journals A Dual-Learning Paradigm Simultaneously Improves Multiple Features of Gait Post-Stroke

2018 ◽  
Vol 32 (9) ◽  
pp. 810-820 ◽  
Author(s):  
Kendra M. Cherry-Allen ◽  
Matthew A. Statton ◽  
Pablo A. Celnik ◽  
Amy J. Bastian
Keyword(s):  
Knee Flexion ◽  
Joint Angle ◽  
Step Length ◽  
Learning Task ◽  
Gait Pattern ◽  
Learning Paradigm ◽  
Post Stroke ◽  
Learning Conditions ◽  
Hip Flexion ◽  
Gait Impairments

Background. Gait impairments after stroke arise from dysfunction of one or several features of the walking pattern. Traditional rehabilitation practice focuses on improving one component at a time, which may leave certain features unaddressed or prolong rehabilitation time. Recent work shows that neurologically intact adults can learn multiple movement components simultaneously. Objective. To determine whether a dual-learning paradigm, incorporating 2 distinct motor tasks, can simultaneously improve 2 impaired components of the gait pattern in people posttroke. Methods. Twelve individuals with stroke participated. Participants completed 2 sessions during which they received visual feedback reflecting paretic knee flexion during walking. During the learning phase of the experiment, an unseen offset was applied to this feedback, promoting increased paretic knee flexion. During the first session, this task was performed while walking on a split-belt treadmill intended to improve step length asymmetry. During the second session, it was performed during tied-belt walking. Results. The dual-learning task simultaneously increased paretic knee flexion and decreased step length asymmetry in the majority of people post-stroke. Split-belt treadmill walking did not significantly interfere with joint-angle learning: participants had similar rates and magnitudes of joint-angle learning during both single and dual-learning conditions. Participants also had significant changes in the amount of paretic hip flexion in both single and dual-learning conditions. Conclusions. People with stroke can perform a dual-learning paradigm and change 2 clinically relevant gait impairments in a single session. Long-term studies are needed to determine if this strategy can be used to efficiently and permanently alter multiple gait impairments.

scholarly journals Temporal Kinematic Differences between Forward and Backward Jump-Landing

2020 ◽  
Vol 17 (18) ◽  
pp. 6669 ◽  
Author(s):  
Datao Xu ◽  
Xuanzhen Cen ◽  
Meizi Wang ◽  
Ming Rong ◽  
Bíró István ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Cruciate Ligament ◽  
Statistical Parametric Mapping ◽  
Time Frame ◽  
Biomechanical Analysis ◽  
Acl Injuries ◽  
Jump Landing ◽  
Vertical Ground ◽  
Anterior Cruciate ◽  
Hip Flexion

Backward jump-landing during sports performance will result in dynamic postural instability with a greater risk of injury, and most research studies have focused on forward landing. Differences in kinematic temporal characteristics between single-leg and double-leg backward jump-landing are seldom researched and understood. The purpose of this study was to compare and analyze lower extremity kinematic differences throughout the landing phases of forward and backward jumping using single-leg and double-leg landings (FS and BS, FD and BD). Kinematic data were collected during the landing phases of FS and BS, FD and BD in 45 participants. Through statistical parametric mapping (SPM) analysis, we found that the BS showed smaller hip and knee flexion and greater vertical ground reactive force (VGRF) than the FS during 0–37.42% (p = 0.031), 16.07–32.11% (p = 0.045), and 23.03–17.32% (p = 0.041) landing phases. The BD showed smaller hip and knee flexion than the FD during 0–20.66% (p = 0.047) and 0–100% (p < 0.001) landing phases. Most differences appeared within a time frame during the landing phase at 30–50 ms in which non-contact anterior cruciate ligament (ACL) injuries are thought to occur and are consistent with the identification of risk in biomechanical analysis. A landing strategy that consciously increases the knee and hip flexion angles during backward landing should be considered for people as a measure to avoid injury during the performance of this type of physical activity.

scholarly journals Comparison of Muscle Activation and Kinematics in 6-RM Squatting With Low and High Barbell Placement

2020 ◽  
Vol 74 (1) ◽  
pp. 131-142
Author(s):  
Roland van den Tillaar ◽  
Eric Helms
Keyword(s):  
Knee Flexion ◽  
Average Velocity ◽  
Muscle Activation ◽  
Joint Kinematics ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Muscular Development ◽  
Hip Flexion ◽  
Maximal Capacity ◽  
Over Time

Abstract The aim of this study was to compare 6-RM muscle activation and kinematics in back squats with low and high barbell placements. Twelve resistance-trained males (23.5 ± 2.6 years, 86.8 ± 21.3 kg, 1.81 ± 0.08 m) with a minimum of 2 years of squatting experience performed a 6-RM using high and low barbell placements while muscle activation of eight muscles and joint kinematics were measured. During high barbell placement squats, lifting time was longer, with lower average velocity than low barbell placement. This was accompanied by a lesser knee flexion angle at the lowest point of the squat, and larger hip flexion angles during high, compared to low barbell squats. Furthermore, peak angular ankle, knee and hip velocities in the descending phase developed differently between conditions. No significant differences in muscle activation were found between conditions. Thus, our data suggests gross muscular adaptations between barbell placements may be similar over time, and therefore, from a muscular development standpoint, both squat styles are valid. Furthermore, unlike the low barbell placement, fatigue may manifest earlier itself in the high barbell squats during 6-RMs as sets progress toward a lifter’s maximal capacity, altering kinematics, especially in the last repetition.

Changes in Distance Running Kinematics with Fatigue

1991 ◽  
Vol 7 (2) ◽  
pp. 138-162 ◽  
Author(s):  
Keith R. Williams ◽  
Rebecca Snow ◽  
Chris Agruss
Keyword(s):  
Factor Analysis ◽  
Knee Flexion ◽  
Step Length ◽  
Analysis Procedure ◽  
Regression Equations ◽  
Knee Flexion Angle ◽  
Distance Running ◽  
Significant Difference ◽  
Individual Variables ◽  
Hip Flexion

This study investigated changes in kinematics with fatigue during intercollegiate competition, a noncompetitive track run, and a constant speed treadmill run. To account for changes in kinematics resulting from speed differences, regression equations for each individual generated from nonfatigue data were used to predict rested kinematics for speeds matching those of the fatigue conditions. A factor analysis procedure grouped 29 kinematic variables into sets of independent factors, and both factor variables and individual variables were analyzed for changes with fatigue, which were minimal. Only one significant difference was found in the factor variables between nonfatigue and fatigue states. Comparisons of specific kinematic variables showed a significant increase in step length with fatigue, an increased maximal knee flexion angle during swing, and an increased maximal thigh angle during hip flexion. While fatigue did not result in marked changes in kinematics for the group as a whole, changes for individuals were at times large.

scholarly journals EFFECT OF STATIC ANATOMIC ALIGNMENT ON DYNAMIC LIMB VALGUS DURING SIDE-STEP CUTTING IN UNINJURED ADOLESCENT ATHLETES

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0002
Author(s):  
Nicole Mueske ◽  
Daniel T. Feifer ◽  
Curtis VandenBerg ◽  
J. Lee Pace ◽  
Mia J. Katzel ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Internal Rotation ◽  
Knee Flexion ◽  
External Rotation ◽  
Acl Injury ◽  
Adolescent Athletes ◽  
Knee Abduction ◽  
Hip Flexion ◽  
Hip Internal Rotation ◽  
Hip Rotation

BACKGROUND Dynamic limb valgus, combining hip adduction and internal rotation with knee abduction posture and moments, has been implicated in ACL injury. However, the contribution of static lower extremity alignment to dynamic limb valgus is unknown. This study assessed the relationships among lower extremity static alignment and dynamic kinematics and kinetics during side-step cutting in uninjured adolescent athletes. METHODS This prospective study included 88 limbs from 44 uninjured athletes aged 8-15 years (mean 12.3, SD 2.3; 19 (44%) female) who were evaluated during an anticipated 45° side-step cut. 3D lower extremity kinematics and kinetics from a custom 6 degree of freedom model were assessed while standing and during the loading phase of the cut from initial contact to peak knee flexion; 2-3 trials per limb were averaged for analysis. Femoral anteversion was measured for each limb with the participant lying prone. Relationships among static and dynamic measures were investigated using correlation and multiple linear regression. RESULTS In terms of static alignment, more static hip internal rotation and more static knee external rotation (tibia external relative to femur) were associated with more internal hip rotation and external knee rotation dynamically during cutting (r=0.34, p=0.001) (Table 1). Static hip adduction was also related to more external hip rotation and less hip flexion dynamically (p=0.24, p=0.02). More static knee abduction, external hip rotation and hip adduction were associated with higher average knee abduction angles during cutting (r=0.25, p=0.02). However, only static external knee rotation was associated with higher dynamic knee abduction moments (r=0.48, p<0.0001) (Figure 1). During cutting, positive associations were observed between hip flexion, knee flexion, and hip internal rotation (r=0.24, p=0.03). Knee adduction angles were related to more hip flexion, internal hip rotation, and knee external rotation (r=0.25, p=0.02). Additionally, lower peak knee flexion was associated with higher peak ground reaction force and more external knee rotation (r=0.24, p=0.02). Both simple correlation and multiple regression analysis indicated that higher knee abduction moments were related dynamically to higher knee abduction angles, greater knee external rotation, higher hip abduction angles, and greater hip internal rotation (R2=0.72, p<0.001). After considering dynamic metrics, no static measure remained significantly related to knee abduction moments. CONCLUSION/SIGNIFICANCE Static knee rotation was the only anatomic alignment measure associated with knee abduction moments during side-step cutting in uninjured adolescent athletes. Knee abduction moments were influenced more by dynamic posture than static alignment. As knee abduction moments have been implicated in ACL injury, this study supports the notion of dynamic limb valgus, specifically increased knee abduction and hip internal rotation, relating to ACL injury. Motion analysis can be used to identify these risky biomechanical patterns, and neuromuscular training can be used to correct them. Since knee abduction moments are primarily determined by dynamic posture, neuromuscular training can be used to reduce these moments and ACL injury risk. [Figure: see text][Table: see text]

scholarly journals A portable exotendon assisting hip and knee joints reduces muscular burden during walking

2021 ◽  
Vol 8 (11) ◽  
Author(s):  
Longfei Cheng ◽  
Caihua Xiong ◽  
Wenbin Chen ◽  
Jiejunyi Liang ◽  
Bo Huang ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Frontal Plane ◽  
Step Length ◽  
Knee Extension ◽  
Knee Joints ◽  
Spring Stiffness ◽  
Step Width ◽  
Step Frequency ◽  
Hip Flexion ◽  
Hip Extension

Assistive devices are used to reduce human effort during locomotion with increasing success. More assistance strategies are worth exploring, so we aimed to design a lightweight biarticular device with well-chosen parameters to reduce muscle effort. Based on the experience of previous success, we designed an exotendon to assist in swing leg deceleration. Then we conducted experiments to test the performance of the exotendon with different spring stiffness during walking. With the assistance of the exotendon, peak activation of semitendinosus decreased, with the largest reduction of 12.3% achieved with the highest spring stiffness ( p = 0.004). The peak activations of other measured muscles were not significantly different ( p = 0.15–0.92). The biological hip extension and knee flexion moments likewise significantly decreased with the spring stiffness ( p < 0.01). The joint angle was altered during the assisted phases with decreased hip flexion and knee extension. Meanwhile, the step frequency and the step length were also altered, while the step width remained unaffected. Gait variability changed only in the frontal plane, exhibiting lower step width variability. We conclude that passive devices assisting hip extension and knee flexion can significantly reduce the burden on the hamstring muscles, while the kinematics is easily altered.

Constraining movement reveals motor capability in chronic stroke: an initial study

2016 ◽  
Vol 31 (8) ◽  
pp. 1126-1133 ◽  
Author(s):  
Clarisa A Martinez ◽  
Emily Mintz ◽  
Andrea E Ecsedy ◽  
Beth E Fisher
Keyword(s):  
Knee Flexion ◽  
Sagittal Plane ◽  
Step Length ◽  
Initial Study ◽  
Swing Phase ◽  
Chronic Stroke ◽  
Task Demands ◽  
Treadmill Walking ◽  
Gait Kinematics ◽  
Hip Flexion

Objective: To determine if persons with chronic stroke and decreased hip and knee flexion during swing can walk with improved swing-phase kinematics when the task demands constrained gait to the sagittal plane. Design: A one-day, within-subject design comparing gait kinematics under two conditions: Unconstrained treadmill walking and a constrained condition in which the treadmill walking space is reduced to limit limb advancement to occur in the sagittal plane. Setting: Outpatient physical therapy clinic. Subjects: Eight individuals (mean age, 64.1 ±9.3, 2 F) with mild-moderate paresis were enrolled. Main measures: Spatiotemporal gait characteristics and swing-phase hip and knee range of motion during unconstrained and constrained treadmill walking were compared using paired t-test and Cohen’s d ( d) to determine effect size. Results: There was a significant, moderate-to-large effect of the constraint on hip flexion ( p < 0.001, d = –1.1) during initial swing, and hip ( p < 0.05, d = –0.8) and knee ( p < 0.001, d = –1.1) flexion during midswing. There was a moderate effect of constraint on terminal swing knee flexion ( p = 0.238, d = –0.6). Immediate and significant changes in step width ( p < 0.05, d = 0.9) and paretic step length ( p < 0.05, d = –0.5) were noted in the constrained condition compared with unconstrained. Conclusion: Constraining the treadmill walking path altered the gait patterns among the study’s participants. The immediate change during constrained walking suggests that patients with chronic stroke may have underlying movement capability that they do not preferentially utilize.

Gluteus Medius Activity during Isometric Closed-Chain Hip Rotation

2002 ◽  
Vol 11 (3) ◽  
pp. 179-188 ◽  
Author(s):  
Randy J. Schmitz ◽  
Bryan L. Riemann ◽  
Timothy Thompson
Keyword(s):  
Knee Flexion ◽  
Gluteus Medius ◽  
Surface Emg ◽  
Upper Body ◽  
Emg Activity ◽  
Forward Movement ◽  
Closed Chain ◽  
Hip Flexion ◽  
Base Of Support ◽  
Hip Rotation

Objective:To determine whether gluteus medius (GM) activity increases in response to isometric closed-chain external hip rotation.Design:Subjects performed single-leg stances in 3 different conditions: 0° knee flexion, 0° hip flexion (C1); 0° knee flexion, 20° hip flexion (C2); and knee flexed 20–30°, 20° hip flexion (C3). Posteriorly directed forces of 8.9 N (F1), 17.8 N (F2), and 26.7 N (F3) were applied at the lateral pelvis of the nonstance side during each condition.Subjects:20 college students.Measurements:Surface EMG RMS amplitude from the GM and kinematic data from the trunk, hip, and knee.Results:Statistical analyses revealed a significant Condition 3 Force interaction and significant increases of EMG activity from C1F1 and C1F2 to C1F3 and from C3F1 to C3F2 and C3F3. F2 and F3 of C2 were significantly less than F2 and F3 of both C1 and C3.Conclusions:GM activity increases in response to isometric, closed-chain, external hip-rotation forces, and forward movement of the upper body with respect to the base of support decreases GM activity.

scholarly journals Biomechanical Characteristics between Bionic Shoes and Normal Shoes during the Drop-Landing Phase: A Pilot Study

2021 ◽  
Vol 18 (6) ◽  
pp. 3223
Author(s):  
Huiyu Zhou ◽  
Chaoyi Chen ◽  
Datao Xu ◽  
Ukadike Chris Ugbolue ◽  
Julien S. Baker ◽  
...  
Keyword(s):  
Lower Limb ◽  
Injury Risk ◽  
Statistical Parametric Mapping ◽  
Frontal Plane ◽  
Lower Limbs ◽  
Lower Limb Injury ◽  
Kinematic Data ◽  
Drop Landing ◽  
Hip Flexion ◽  
And Inversion

With the development of unstable footwear, more research has focused on the advantages of this type of shoe. This type of shoe could improve the muscle function of the lower limb and prevent injury risks in dynamic situations. Therefore, the purpose of this study was to investigate differences in lower-limb kinetics and kinematics based on single-leg landing (SLL) using normal shoes (NS) and bionic shoes (BS). The study used 15 male subject volunteers (age 23.4 ± 1.14 years, height 177.6 ± 4.83cm, body weight (BW) 73.6 ± 7.02 kg). To ensure the subject standardization of the participants, there were several inclusion criteria used for selection. There were two kinds of experimental shoes used in the landing experiment to detect the change of lower limbs when a landing task was performed. Kinetics and kinematic data were collected during an SLL task, and statistical parametric mapping (SPM) analysis was used to evaluate the differences between NS and BS. We found that the flexion and extension angles of the knee (p = 0.004) and hip (p = 0.046, p = 0.018) joints, and the dorsiflexion and plantarflexion of ankle (p = 0.031) moment were significantly different in the sagittal planes. In the frontal plane, the eversion and inversion of the ankle (p = 0.016), and the abduction and adduction of knee (p = 0.017, p = 0.007) angle were found significant differences. In the horizontal plane, the external and internal rotation of hip (p = 0.036) and knee (p < 0.001, p = 0.029) moment were found significant differences, and knee angle (p = 0.043) also. According to our results, we conclude that using BS can cause bigger knee and hip flexion than NS. Also, this finding indicates that BS might be considered to reduce lower-limb injury risk during the SLL phase.

Legal Update: North Dakota Supreme Court: Third Edition of Guides is “Most Current”

1999 ◽  
Vol 4 (1) ◽  
pp. 6-7
Author(s):  
James J. Mangraviti
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Measurement Techniques ◽  
Fourth Edition ◽  
Hip Motion ◽  
The Difference ◽  
The Right ◽  
Hip Flexion ◽  
Hip Rotation ◽  
Hip Extension

Abstract The accurate measurement of hip motion is critical when one rates impairments of this joint, makes an initial diagnosis, assesses progression over time, and evaluates treatment outcome. The hip permits all motions typical of a ball-and-socket joint. The hip sacrifices some motion but gains stability and strength. Figures 52 to 54 in AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, illustrate techniques for measuring hip flexion, loss of extension, abduction, adduction, and external and internal rotation. Figure 53 in the AMA Guides, Fourth Edition, illustrates neutral, abducted, and adducted positions of the hip and proper alignment of the goniometer arms, and Figure 52 illustrates use of a goniometer to measure flexion of the right hip. In terms of impairment rating, hip extension (at least any beyond neutral) is irrelevant, and the AMA Guides contains no figures describing its measurement. Figure 54, Measuring Internal and External Hip Rotation, demonstrates proper positioning and measurement techniques for rotary movements of this joint. The difference between measured and actual hip rotation probably is minimal and is irrelevant for impairment rating. The normal internal rotation varies from 30° to 40°, and the external rotation ranges from 40° to 60°.

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