EFFECTIVENESS OF FLOOR MARKINGS FOR CONTROLLING CUT WIDTH DURING SIDE CUTTING TASKS IN LABORATORY EXPERIMENTS

2020 ◽  
Vol 20 (01) ◽  
pp. 1950076
Author(s):  
JING WEN PAN ◽  
THORSTEN STERZING ◽  
JUN WEI PANG ◽  
YAOHUI KELVIN CHUA ◽  
PUI WAH KONG
Keyword(s):  
Lower Extremity ◽  
Hip Joint ◽  
Laboratory Experiments ◽  
Ground Reaction Forces ◽  
Basketball Players ◽  
Foot Placement ◽  
Body Postures ◽  
Motion Data ◽  
Reaction Forces ◽  
The Difference

This study examined the effectiveness of floor markings for controlling cut width during the analysis of side cutting maneuvers. Eleven male basketball players performed two side cutting maneuvers of narrow (30[Formula: see text]cm) and wide (45[Formula: see text]cm) cut widths and were guided by floor markings. Ground reaction forces, together with ankle, knee, and hip joint ranges of motion (ROM), and respective joint moments were determined. Cut widths were verified by two approaches by calculating the actual foot-to-foot and foot-to-pelvis distances from motion data. Biomechanical lower extremity loading showed no significant differences in most kinetic and kinematic variables between narrow and wide cuts. The difference in foot-to-foot distance (15.1 [11.6, 18.7] cm, [Formula: see text] between conditions corresponded well with floor markings, however, the difference in foot-to-pelvis distance was much smaller (2.3 [0.3, 4.4] cm, [Formula: see text]. It is concluded that floor markings are not sufficient for controlling the actual anatomical cut width in laboratory experiments. Participants may adjust their body postures to maintain similar lower extremity loading when performing side cuts differing in foot placement width. Cut width should be represented by foot-to-pelvis distance and not foot-to-foot distance.

scholarly journals Hop-Stabilization Training and Landing Biomechanics in Athletes With Chronic Ankle Instability: A Randomized Controlled Trial

2019 ◽  
Vol 54 (12) ◽  
pp. 1296-1303 ◽  
Author(s):  
Mohammad Karimizadeh Ardakani ◽  
Erik A. Wikstrom ◽  
Hooman Minoonejad ◽  
Reza Rajabi ◽  
Ali Sharifnezhad
Keyword(s):  
Lower Extremity ◽  
Training Program ◽  
Ankle Instability ◽  
Control Group ◽  
Ground Reaction Forces ◽  
Basketball Players ◽  
Jump Landing ◽  
Randomized Controlled ◽  
Landing Biomechanics ◽  
Reaction Forces

Context Hopping exercises are recommended as a functional training tool to prevent lower limb injury, but their effects on lower extremity biomechanics in those with chronic ankle instability (CAI) are unclear. Objective To determine if jump-landing biomechanics change after a hop-stabilization intervention. Design Randomized controlled clinical trial. Setting Research laboratory. Patients or Other Participants Twenty-eight male collegiate basketball players with CAI were divided into 2 groups: hop-training group (age = 22.78 ± 3.09 years, mass = 82.59 ± 9.51 kg, height = 187.96 ± 7.93 cm) and control group (age = 22.57 ± 2.76 years, mass = 78.35 ± 7.02 kg, height = 185.69 ± 7.28 cm). Intervention(s) A 6-week supervised hop-stabilization training program that consisted of 18 training sessions. Main Outcome Measure(s) Lower extremity kinetics and kinematics during a jump-landing task and self-reported function were assessed before and after the 6-week training program. Results The hop-stabilization program resulted in improved self-reported function (P < .05), larger sagittal-plane hip- and knee-flexion angles, and greater ankle dorsiflexion (P < .05) relative to the control group. Reduced frontal-plane joint angles at the hip, knee, and ankle as well as decreased ground reaction forces and a longer time to peak ground reaction forces were observed in the hopping group compared with the control group after the intervention (P < .05). Conclusions The 6-week hop-stabilization training program altered jump-landing biomechanics in male collegiate basketball players with CAI. These results may provide a potential mechanistic explanation for improvements in patient-reported outcomes and reductions in injury risk after ankle-sprain rehabilitation programs that incorporate hop-stabilization exercises.

Effects of arch-support orthoses on ground reaction forces and lower extremity kinematics related to running at various inclinations

2020 ◽  
Vol 38 (14) ◽  
pp. 1629-1634
Author(s):  
Wing-Kai Lam ◽  
Lok-Yee Pak ◽  
Charis King-Wai Wong ◽  
Mohammad Farhan Tan ◽  
Sang-Kyoon Park ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Forces ◽  
Reaction Forces ◽  
Arch Support

scholarly journals Characteristics of Autocorrelation Structure of Lower Extremity Functional Laterality in Disturbed and Undisturbed Bipedal Upright Stance

2016 ◽  
Vol 17 (4) ◽  
Author(s):  
Jacek Stodółka ◽  
Weronika Stodółka ◽  
Jarosław Gambal ◽  
Tom Raunig
Keyword(s):  
Lower Extremity ◽  
Autocorrelation Function ◽  
Human Mobility ◽  
Time Frame ◽  
Standing Position ◽  
Ground Reaction Forces ◽  
Upright Stance ◽  
Functional Laterality ◽  
Eyes Open ◽  
Reaction Forces

AbstractPurpose. It is posited that functional laterality is influenced by the generation and conduction of neural signals and therefore associated with sensorimotor control. The question arises if symmetry or asymmetry in sensorimotor processing affects the development of symmetric or asymmetric motor programs in the lower extremities. The purpose of the study was to examine the mechanisms of the human mobility moto-control - the process of maintaining body balance in a standing position through an appropriate course of distribution of ground reaction forces in a time frame, in a situation requiring lower extremity movement symmetry. Methods. The autocorrelation function was calculated for ground reaction forces (in the three orthogonal axes) registered during 45 s of bipedal upright stance in two conditions (eyes open and closed). Results. Minor albeit significant deficiencies in postural muscle control were revealed as a function of time, as evidenced in the decay of the autocorrelation function to zero (T

Ground Reaction Forces and Lower Extremity Kinematics When Running With Suppressed Arm Swing

2009 ◽  
Vol 131 (12) ◽  
Author(s):  
Ross H. Miller ◽  
Graham E. Caldwell ◽  
Richard E. A. Van Emmerik ◽  
Brian R. Umberger ◽  
Joseph Hamill
Keyword(s):  
Lower Extremity ◽  
Research Question ◽  
Ground Reaction Forces ◽  
Joint Angles ◽  
Arm Swing ◽  
Musculoskeletal Models ◽  
Reaction Forces ◽  
Cross Correlations ◽  
Arm Motion ◽  
Hip Flexion

The role of arm swing in running has been minimally described, and the contributions of arm motion to lower extremity joint kinematics and external force generation are unknown. These contributions may have implications in the design of musculoskeletal models for computer simulations of running, since previous models have usually not included articulating arm segments. 3D stance phase lower extremity joint angles and ground reaction forces (GRFs) were determined for seven subjects running normally, and running under two conditions of arm restraint. When arm swing was suppressed, the peak vertical GRF decreased by 10–13% bodyweight, and the peak lateral GRF increased by 4–6% bodyweight. Changes in peak joint angles on the order of 1–5 deg were observed for hip flexion, hip adduction, knee flexion, knee adduction, and ankle abduction. The effect sizes (ES) were small to moderate (ES<0.8) for most of the peak GRF differences, but large (ES>0.8) for most of the peak joint angle differences. These changes suggest that suppression of arm swing induces subtle but statistically significant changes in the kinetic and kinematic patterns of running. However, the salient features of the GRFs and the joint angles were present in all conditions, and arm swing did not introduce any major changes in the timing of these data, as indicated by cross correlations. The decision to include arm swing in a computer model will likely need to be made on a case-by-case basis, depending on the design of the study and the accuracy needed to answer the research question.

scholarly journals Lower extremity stiffness in habitual forefoot strikers during running on different overground surfaces

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Ziwei Zeng ◽  
Lulu Yin ◽  
Wenxing Zhou ◽  
Yu Zhang ◽  
Jiayi Jiang ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Sagittal Plane ◽  
Joint Stiffness ◽  
Ground Reaction Forces ◽  
Factors Affecting ◽  
Vertical Stiffness ◽  
Synthetic Rubber ◽  
Peak Knee ◽  
Reaction Forces ◽  
Artificial Grass

Purpose: Sports surface is one of the known external factors affecting running performance and injury. To date, we have found no study that examined the lower extremity stiffness in habitual forefoot strikers running on different overground surfaces. Therefore, the objective of this study was to investigate lower extremity stiffness and relevant kinematic adjustments in habitual forefoot strikers while running on different surfaces. Methods: Thirty-one male habitual forefoot strikers were recruited in this study. Runners were instructed to run at a speed of 3.3 m/s (±5%) on three surfaces, named synthetic rubber, concrete, and artificial grass. Results: No significant differences were found in leg stiffness, vertical stiffness, and joint stiffness in the sagittal plane during running on the three surfaces (p > 0.05). Running on artificial grass exerted a greater displacement in knee joint angle than running on synthetic rubber (p = 0.002, 95% CI = 1.52–7.35 degrees) and concrete (p = 0.006, 95% CI = 1.04–7.25 degrees). In the sagittal plane, peak knee moment was lower on concrete than on artificial grass (p = 0.003, 95% CI = 0.11–0.58 Nm/kg), whereas peak ankle moment was lower on synthetic rubber than on concrete (p < 0.001, 95% CI = 0.03–0.07 Nm/kg) and on artificial grass (p < 0.001, 95% CI = 0.02–0.06 Nm/kg). Among the three surfaces, the maximal ground reaction forces on concrete were the lowest (p < 0.05). Conclusions: This study indicated that running surfaces cannot influence lower extremity stiffness in habitual forefoot strikers at current running speed. Kinematic adjustments of knee and ankle, as well as ground reaction forces, may contribute to maintaining similar lower extremity stiffness.

scholarly journals Gait consistency test based on the impulse-momentum theorem

1979 ◽  
Vol 3 (2) ◽  
pp. 91-98 ◽  
Author(s):  
R. Seliktar ◽  
M. Yekutiel ◽  
A. Bar
Keyword(s):  
Test Procedure ◽  
Human Locomotion ◽  
Sufficient Evidence ◽  
Ground Reaction Forces ◽  
Quantitative Parameter ◽  
Consistency Test ◽  
Time Integral ◽  
Reaction Forces ◽  
Pathological Gait ◽  
The Difference

The kinematic and dynamic aspects of human locomotion have been investigated during the last eighty years. Significant contributions were made towards the understanding of the mechanics of movement and of the joints. As a consequence the field of Rehabilitation and Orthopaedic Biomechanics advanced considerably. However the complexity of the kinematic and dynamic data of locomotion prevented the various techniques from becoming clinically applicable. This paper attempts to develop a technique for clinical evaluation of gait by relatively simple means. For this purpose the six components of the ground reaction forces were chosen for an analysis. The major tool of the technique is the time integral of the forces. Since this is a quantitative parameter with a distinct physical definition, it can be very meaningful as far as investment of efforts in ambulation is concerned. As a first step towards the reinforcement of this thesis a consistency test was developed. The consistency test ensures that the use of dynamic forceplates do not impose a bias on the test procedure. The test is meant to indicate whether the results are valid for further processing. The concept of the test is based on the fact that the velocity vector is expected to be equal in two equivalent points of consecutive walk cycles. It therefore follows that the time-force integral which equals the difference of momentum between the two points should be zero. The advantage of this test is that it does not discriminate between normal and pathological gait. The theory was tested with 28 subjects and the results have provided sufficient evidence for its verification.

Torque patterns of the limbs of small therian mammals during locomotion on flat ground

2002 ◽  
Vol 205 (9) ◽  
pp. 1339-1353 ◽  
Author(s):  
Hartmut Witte ◽  
Jutta Biltzinger ◽  
Rémi Hackert ◽  
Nadja Schilling ◽  
Manuela Schmidt ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Hip Joint ◽  
Time Course ◽  
Wrist Joint ◽  
Ground Reaction Forces ◽  
Inverse Dynamic ◽  
Scanning Method ◽  
Joint Torques ◽  
Joint Forces ◽  
Reaction Forces

SUMMARY In three species of small therian mammals (Scandentia: Tupaia glis, Rodentia: Galea musteloides and Lagomorpha: Ochotona rufescens) the net joint forces and torques acting during stance phase in the four kinematically relevant joints of the forelimbs (scapular pivot,shoulder joint, elbow joint, wrist joint) and the hindlimbs (hip joint, knee joint, ankle joint, intratarsal joint) were determined by inverse dynamic analysis. Kinematics were measured by cineradiography (150 frames s-1). Synchronously ground reaction forces were acquired by forceplates. Morphometry of the extremities was performed by a scanning method using structured illumination. The vector sum of ground reaction forces and weight accounts for most of the joint force vector. Inertial effects can be neglected since errors of net joint forces amount at most to 10 %. The general time course of joint torques is comparable for all species in all joints of the forelimb and in the ankle joint. Torques in the intratarsal joints differ between tailed and tail-less species. The torque patterns in the knee and hip joint are unique to each species. For the first time torque patterns are described completely for the forelimb including the scapula as the dominant propulsive segment. The results are compared with the few torque data available for various joints of cats(Felis catus), dogs (Canis lupus f. familiaris),goats (Capra sp.) and horses (Equus przewalskii f. caballus).

scholarly journals Contribution of Cutaneous Inputs From the Hindpaw to the Control of Locomotion. I. Intact Cats

2003 ◽  
Vol 90 (6) ◽  
pp. 3625-3639 ◽  
Author(s):  
L.J.G. Bouyer ◽  
S. Rossignol
Keyword(s):  
Control Level ◽  
Companion Paper ◽  
Treadmill Walking ◽  
Emg Activity ◽  
Ground Reaction Forces ◽  
Phase Duration ◽  
Foot Placement ◽  
Cutaneous Feedback ◽  
Adaptive Mechanisms ◽  
Reaction Forces

The goal of this study was to evaluate the role of hindpaw cutaneous feedback in the control of locomotion, by cutting some (in one cat) or all (in 2 cats) cutaneous nerves bilaterally at ankle level. Kinematic and electromyographic (EMG) recordings were obtained before and for several weeks after denervation during level and incline (15° up and down) treadmill walking. Ladder walking and ground reaction forces were also documented sporadically. Early after the denervation (1–3 days), cats could not walk across a ladder, although deficits were small during level treadmill walking. Increased knee flexion velocity caused a 14% reduction in swing phase duration. EMG activity was consistently increased in knee, ankle, and toe flexors, and in at least one knee or ankle extensor. The adaptive changes during walking on the incline were much reduced after denervation. Ladder walking gradually recovered within 3–7 wk. By this time, level treadmill walking kinematics had completely returned to normal, but EMG activity in flexors remained above control. Incline walking improved but did not return to normal. Mediolateral ground reaction forces during overground walking were increased by 200%. It is concluded that in intact cats, cutaneous inputs contribute more to demanding situations such as walking on a ladder or on inclines than to level walking. Active adaptive mechanisms are likely involved given that the EMG locomotor pattern never returned to control level. The companion paper shows on the other hand that when the same cats are spinalized, these cutaneous inputs become critical for foot placement during locomotion.

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