Lower Extremity Mechanics During Marching at Three Different Cadences for 60 Minutes

2014 ◽  
Vol 30 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Joseph F. Seay ◽  
Peter N. Frykman ◽  
Shane G. Sauer ◽  
David J. Gutekunst
Keyword(s):  
Lower Extremity ◽  
Mechanical Stress ◽  
Ground Reaction Force ◽  
Stance Phase ◽  
Reaction Force ◽  
Knee Extension ◽  
Force Sensing ◽  
Joint Mechanics ◽  
Step Rate

During group marches, soldiers must walk in step with one another at the same imposed cadence. The literature suggests that shorter trainees may be more susceptible to injury due to overstriding that can occur when taller recruits dictate marching cadence. This study assessed the effects of fixed cadence simulated marching at cadences above and below preferred step rate (PSR) on lower extremity joint mechanics in individuals who were unaccustomed to marching. During three separate visits, 13 volunteers walked with a 20 kg load on a force-sensing treadmill at self-selected PSR, PSR+15% (shorter strides), and PSR–15% (longer strides) at 1.3 m/s for 60 min. Two-way RM ANOVAs (cadence by time) were performed during the stance phase. Ranges of motion and anteroposterior ground reaction force increased significantly as cadence decreased (P< .03). Knee extension moment increased slightly when step rate decreased from PSR+15% (shortest strides, 0.85 ± 0.2 N m/kg) to PSR (0.87 ± 0.3 N m/kg, 3% increase); however, this increase was substantially greater (20% increase) when cadence was decreased from PSR to PSR–15% (longest strides, 1.09 ± 0.3 N m/kg). Our results indicate that overstriding during fixed-cadence marching is a factor that can substantially increase mechanical stress on lower extremity joints.

scholarly journals Immediate Effect of Restricted Knee Extension on Ground Reaction Force and Trunk Acceleration during Walking

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Hiroshi Osaka ◽  
Daisuke Fujita ◽  
Kenichi Kobara ◽  
Tadanobu Suehiro
Keyword(s):  
Ground Reaction Force ◽  
Stance Phase ◽  
Gait Cycle ◽  
Reaction Force ◽  
Gait Pattern ◽  
Knee Extension ◽  
Measurement Unit ◽  
Gait Parameters ◽  
Significant Difference ◽  
Trunk Acceleration

Gait parameters calculated from trunk acceleration reflect the features of gait; however, they cannot evaluate the gait pattern corresponding to the gait cycle. This study is aimed at investigating the differences in gait parameters calculated from trunk acceleration during gait corresponding to the gait cycle in healthy subjects with restricted knee extension. Participants included eight healthy volunteers who walked normally (NW) and with knee orthosis that restricted knee extension (ER). The ground reaction force (GRF), joint angles, and trunk acceleration during walking were measured using four force plates, a three-dimensional motion analysis system, and an inertial measurement unit. The peak GRF of the vertical components, joint ranges of motion, and moments of force were analyzed. The root mean square (RMS) and amplitude peak ratio (AR) of autocorrelation function were calculated from the trunk acceleration waveform. The first peak GRF and peak ankle dorsiflexion angles significantly increased during ER. The peak hip extension, knee flexion, knee extension angles, and the peak moment of knee extension significantly decreased during ER compared to that during NW. The acceleration AR significantly decreased during ER compared to that during NW. There was no significant difference in the RMS between the two conditions. The acceleration AR may show the temporal postural structure with restricted knee extension from the terminal stance phase for the ipsilateral limb to the initial stance phase for the contralateral limb. These results suggest that novel metrics for accelerometry gait analysis can reveal gait abnormalities, with restricted knee extension corresponding to the gait cycle.

Bilateral Squatting Mechanics Are Associated With Landing Mechanics in Anterior Cruciate Ligament Reconstruction Patients

2021 ◽  
pp. 036354652110237
Author(s):  
Alexander T. Peebles ◽  
Blaise Williams ◽  
Robin M. Queen
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Knee Extension ◽  
Abduction Angle ◽  
Return To Sports ◽  
Vertical Ground Reaction Force ◽  
Peak Knee ◽  
Knee Abduction ◽  
Vertical Ground

Background: Proper lower extremity biomechanics during bilateral landing is important for reducing injury risk in athletes returning to sports after anterior cruciate ligament reconstruction (ACLR). Although landing is a quick ballistic movement that is difficult to modify, squatting is a slower cyclic movement that is ideal for motor learning. Hypothesis: There is a relationship between lower extremity biomechanics during bilateral landing and bilateral squatting in patients with an ACLR. Study Design: Descriptive laboratory study. Methods: A total of 41 patients after a unilateral ACLR (24 men, 17 women; 5.9 ± 1.4 months after ACLR) completed 15 unweighted bilateral squats and 10 bilateral stop-jumps. Three-dimensional lower extremity kinematics and kinetics were collected, and peak knee abduction angle, knee abduction/adduction range of motion, peak vertical ground-reaction force limb symmetry index (LSI), vertical ground-reaction force impulse LSI, and peak knee extension moment LSI were computed during the descending phase of the squatting and landing tasks. Wilcoxon signed-rank tests were used to compare each outcome between limbs, and Spearman correlations were used to compare outcomes between the squatting and landing tasks. Results: The peak vertical ground reaction force, the vertical ground reaction force impulse, and the peak knee extension moment were reduced in the surgical (Sx) limb relative to the nonsurgical (NSx) limb during both the squatting and landing tasks ( P < .001). The relationship between squatting and landing tasks was strong for the peak knee abduction angle ( R = 0.697-0.737; P < .001); moderate for the frontal plane knee range of motion (NSx: R = 0.366, P = .019; Sx: R = 0.418, P = 0.007), the peak knee extension moment LSI ( R = 0.573; P < .001), the vertical ground reaction force impulse LSI ( R = 0.382; P < .014); and weak for the peak vertical ground reaction force LSI ( R = 0.323; P = .039). Conclusion: Patients who have undergone an ACLR continue to offload their surgical limb during both squatting and landing. Additionally, there is a relationship between movement deficits during squatting and movement deficits during landing in patients with an ACLR preparing to return to sports. Clinical Relevance: As movement deficits during squatting and landing were related before return to sports, this study suggests that interventional approaches to improve squatting biomechanics may translate to improved landing biomechanics in patients with an ACLR.

Ground Reaction Force in Sit-to-stand Reflects Lower-extremity Function Better than Timed Test in Older Adults

2011 ◽  
Vol 43 (Suppl 1) ◽  
pp. 930-931
Author(s):  
Taishi Tsuji ◽  
Tomohiro Okura ◽  
Kenji Tsunoda ◽  
Yasuhiro Mitsuishi ◽  
Naruki Kitano ◽  
...  
Keyword(s):  
Older Adults ◽  
Lower Extremity ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Lower Extremity Function ◽  
Sit To Stand ◽  
Extremity Function ◽  
Timed Test ◽  
Better Than

scholarly journals Influence of Difference of Dynamic Alignment in the Lower Extremity on Ground Reaction Force during One Step Movement

2004 ◽  
Vol 19 (4) ◽  
pp. 317-322
Author(s):  
Hitomi AWAI ◽  
Goro KIMURA ◽  
Hiroaki KONNO ◽  
Hitomi TOKUMOTO ◽  
Yumiko MATSUBARA ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Step Movement ◽  
One Step ◽  
Dynamic Alignment

scholarly journals The Kinematics and Kinetics Analysis of the Lower Extremity in the Landing Phase of a Stop-jump Task

2015 ◽  
Vol 9 (1) ◽  
pp. 103-107 ◽  
Author(s):  
L Yin ◽  
D Sun ◽  
Q.C Mei ◽  
Y.D Gu ◽  
J.S Baker ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
Flexion Angle ◽  
Contact Phase ◽  
Peak Knee ◽  
Significant Difference ◽  
The Impact ◽  
Kinematics And Kinetics

Large number of studies showed that landing with great impact forces may be a risk factor for knee injuries. The purpose of this study was to illustrate the different landing loads to lower extremity of both genders and examine the relationships among selected lower extremity kinematics and kinetics during the landing of a stop-jump task. A total of 35 male and 35 female healthy subjects were recruited in this study. Each subject executed five experiment actions. Lower extremity kinematics and kinetics were synchronously acquired. The comparison of lower extremity kinematics for different genders showed significant difference. The knee and hip maximum flexion angle, peak ground reaction force and peak knee extension moment have significantly decreased during the landing of the stop-jump task among the female subjects. The hip flexion angle at the initial foot contact phase showed significant correlation with peak ground reaction force during landing of the stop-jump task (r=-0.927, p<0.001). The knee flexion angle at the initial foot contact phase had significant correlation with peak ground reaction force and vertical ground reaction forces during landing of the stop-jump task (r=-0.908, p<0.001; r=0.812, P=0.002). A large hip and knee flexion angles at the initial foot contact with the ground did not necessarily reduce the impact force during landing, but active hip and knee flexion motions did. The hip and knee flexion motion of landing was an important technical factor that affects anterior cruciate ligament (ACL) loading during the landing of the stop-jump task.

A Comparison of Computation Methods for Leg Stiffness During Hopping

2014 ◽  
Vol 30 (1) ◽  
pp. 154-159 ◽  
Author(s):  
Hiroaki Hobara ◽  
Koh Inoue ◽  
Yoshiyuki Kobayashi ◽  
Toru Ogata
Keyword(s):  
Ground Reaction Force ◽  
Stance Phase ◽  
Center Of Mass ◽  
Reaction Force ◽  
Sine Wave ◽  
Phase Method ◽  
Leg Stiffness ◽  
Mass Displacement ◽  
Male Subjects ◽  
Oscillation Method

Despite the presence of several different calculations of leg stiffness during hopping, little is known about how the methodologies produce differences in the leg stiffness. The purpose of this study was to directly compareKlegduring hopping as calculated from three previously published computation methods. Ten male subjects hopped in place on two legs, at four frequencies (2.2, 2.6, 3.0, and 3.4 Hz). In this article, leg stiffness was calculated from the natural frequency of oscillation (method A), the ratio of maximal ground reaction force (GRF) to peak center of mass displacement at the middle of the stance phase (method B), and an approximation based on sine-wave GRF modeling (method C). We found that leg stiffness in all methods increased with an increase in hopping frequency, butKlegvalues using methods A and B were significantly higher than when using method C at all hopping frequencies. Therefore, care should be taken when comparing leg stiffness obtained by method C with those calculated by other methods.

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