scholarly journals Correlations between Pre-landing Sagittal Plane Kinematics and Posterior Ground Reaction Force during Single-leg Anterior Jump-landing

2017 ◽  
Vol 32 (6) ◽  
pp. 751-755
Author(s):  
Shunsuke OHJI ◽  
Junya AIZAWA ◽  
Kenji HIROHATA ◽  
Takehiro OHMI ◽  
Kazuyoshi YAGISHITA
Keyword(s):  
Ground Reaction Force ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Jump Landing

A New Lower Extremity Modeling of Human Body With Variable Feet Links

2000 ◽  
Author(s):  
Nader Arafati ◽  
Jean Yves Lazennec ◽  
Roger Ohayon
Keyword(s):  
Ground Reaction Force ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Human Movement ◽  
Knee Joints ◽  
Foot Pressure ◽  
Ankle Joints ◽  
Reaction Forces ◽  
Human Movement Modeling ◽  
Force Vectors

Abstract Human movement modeling has been the object of much research for the past 30 years. In these models the position of foot link was fixed on the ground. We propose to model the feet links as variable, since the position of foot pressure center changes from heel to toes. The ground reaction forces could also be analyzed in real time. We examined this model for some static postures. In standing anatomical position, the maximum articular forces are localized in hip and knee joints. In sagittal plane, the ground reaction force vectors are positioned nearly under ankle joints. The pathological postures like body with pes cavus or with global spine kyphosis increase the articular and muscular forces. In these cases, the position of ground reaction force vectors is moved toward the toes.

The evaluation of modified foot orthosis on muscle activity and kinetic in a subject with flexible flat foot : Single case study

2013 ◽  
Vol 38 (2) ◽  
pp. 160-166 ◽  
Author(s):  
Hassan Saeedi ◽  
Mohammad E Mousavi ◽  
Basir Majddoleslam ◽  
Mehdi Rahgozar ◽  
Gholamreza Aminian ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Muscle Activity ◽  
Sagittal Plane ◽  
Single Case ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Flat Foot ◽  
Case Evaluation ◽  
The University ◽  
Foot Orthosis

Background:Due to blocking of pronation/dorsiflexion in flexible flat foot and restriction of these movements in using the University of California Berkeley Laboratory orthosis, provided pressures in sole by the orthosis were increased. Therefore, this article describes the evaluation of modified foot orthosis with flexible structure in the management of individuals with flexible flat foot.Case description and method:The patient was a 21-year-old male who had symptomatic flat foot. The modified foot orthosis included movable surface and the outside structure. The modified foot orthosis was evaluated by standing foot X-ray, comfort rate, electromyography of leg muscle and vertical ground reaction force during walking.Findings and outcomes:The modified foot orthosis improved the foot alignment and decreased the symptoms of flat foot with more comfort. Subtalar position by sub-maximum supination had higher position than neutral in sagittal plane. It may increase the muscle activity of peroneus longus by 7% compared to barefoot, and there was a decrease of 11% ground reaction force in mid stance.Conclusion:The result of this single case evaluation only proposed the feasibility of this modified insole as the orthotic treatment in flexible flat foot.Clinical relevanceThe modified foot orthosis, which is mobile in the midfoot, is an orthosis for walking and standing in subjects with flexible flat foot.

The Effects of Sprinting Induced Fatigue on Ground Reaction Force Symmetry in Jump Landing Kinetics

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S400
Author(s):  
Mindy Bennett ◽  
Kathy Berg ◽  
Chad Harris ◽  
Kristof Kipp ◽  
Mark DeBeliso ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Jump Landing

Patellar Tendon Straps Decrease Pain and May Alter Lower Extremity Kinetics in Those With Patellar Tendinopathy During Jump Landing

2017 ◽  
Vol 22 (4) ◽  
pp. 51-57 ◽  
Author(s):  
Adam B. Rosen ◽  
Jupil Ko ◽  
Kathy J. Simpson ◽  
Cathleen N. Brown
Keyword(s):  
Lower Extremity ◽  
Patellar Tendon ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Patellar Tendinopathy ◽  
Jump Landing ◽  
Drop Jumps ◽  
Kinetics Of

Patellar tendinopathy is often managed with a patellar tendon strap, however, their effectiveness is unsubstantiated. The purpose of this study was to determine if straps altered pain or lower extremity kinetics of individuals with patellar tendinopathy during landing. Thirty participants with patellar tendinopathy and 30 controls completed drop jumps with and without patellar tendon straps. Wearing the strap, tendinopathy participants demonstrated significantly decreased pain and reduced knee adductor moment; all participants displayed significantly decreased anterior ground reaction force while wearing a strap. Patellar tendon strapping may reduce pain due to alterations in direction and magnitude of loading.

Peak ACL force during jump landing in downhill skiing is less sensitive to landing height than landing position

2018 ◽  
Vol 52 (17) ◽  
pp. 1086-1090 ◽  
Author(s):  
Dieter Heinrich ◽  
Antonie J van den Bogert ◽  
Werner Nachbauer
Keyword(s):  
Sagittal Plane ◽  
Reaction Force ◽  
Joint Reaction Force ◽  
Dynamic Optimisation ◽  
Landing Position ◽  
Jump Landing ◽  
Shear Component ◽  
Sensitivity Studies ◽  
Downhill Skiing ◽  
Knee Muscle

BackgroundCompetitive skiers face a high risk of sustaining an ACL injury during jump landing in downhill skiing. There is a lack of knowledge on how landing height affects this risk.ObjectivesTo evaluate the effect of varied landing height on peak ACL force during jump landing and to compare the effect of the landing height with the effect of the landing position varied by the trunk lean of the skier.MethodsA 25-degree-of-freedom sagittal plane musculoskeletal model of an alpine skier, accompanied by a dynamic optimisation framework, was used to simulate jump landing manoeuvres in downhill skiing. First, a reference simulation was computed tracking experimental data of competitive downhill skier performing a jump landing manoeuvre. Second, sensitivity studies were performed computing 441 landing manoeuvres with perturbed landing height and trunk lean of the skier, and the corresponding effects on peak ACL force were determined.ResultsThe sensitivity studies revealed that peak ACL force increased with jump height and backward lean of the skier as expected. However, peak ACL was about eight times more sensitive to the trunk lean of the skier compared with landing height. The decreased sensitivity of the landing height was based on the lower effects on the knee muscle forces and the shear component of the knee joint reaction force.ConclusionPreventive measures are suggested to focus primarily on avoiding trunk backward lean of the skier, and consequently on proper jump preparation and technique, and secondarily on strategies to reduce landing height during jumps.

Effect of ankle-foot orthosis on level walking in healthy subjects

2019 ◽  
Vol 233 (12) ◽  
pp. 1262-1268
Author(s):  
Mizuki Kato ◽  
Arinori Kamono ◽  
Naomichi Ogihara
Keyword(s):  
Ground Reaction Force ◽  
Healthy Subjects ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Walking Ability ◽  
Vertical Ground Reaction Force ◽  
Walking Gait ◽  
Ankle Foot Orthosis ◽  
Heel Contact ◽  
Foot Orthosis

An ankle-foot orthosis is often prescribed in the rehabilitation of patients with neurological motor disorders such as hemiparesis. However, walking with a unilateral ankle-foot orthosis may not be effectively achieved just by trying to reproduce normal intact walking with a symmetrical gait pattern. Understanding skills to facilitate walking gait with a unilateral ankle-foot orthosis has implications for better rehabilitative interventions to help restore walking ability in patients with stroke. We, therefore, analyzed the kinematics and ground reaction forces of walking with and without an ankle-foot orthosis in healthy subjects to infer the possible skills to facilitate walking gait with a unilateral ankle-foot orthosis. Adult male participants were asked to walk with and without an ankle-foot orthosis across two force platforms set in a wooden walkway, and body kinematics and ground reaction force profiles in the sagittal plane were simultaneously recorded. We found that the forward tilting angle of the trunk at the time of toe-off of the leg with the ankle-foot orthosis was significantly larger than that of the leg without the ankle-foot orthosis, to adaptively compensate for the loss of ankle joint mobility due to the unilateral ankle-foot orthosis. Furthermore, the peak vertical ground reaction force at heel-contact was significantly larger in the leg without the ankle-foot orthosis than in the leg with the ankle-foot orthosis owing to the fact that the stance phase duration of the leg with the ankle-foot orthosis was relatively shorter. Such information may potentially be applied to facilitate walking training in stroke patients wearing a unilateral ankle-foot orthosis.

scholarly journals Restrictions in Ankle Dorsiflexion Range of Motion Alter Landing Kinematics But Not Movement Strategy When Fatigued

2020 ◽  
pp. 1-9
Author(s):  
Louis Howe ◽  
Jamie S. North ◽  
Mark Waldron ◽  
Theodoros M. Bampouras
Keyword(s):  
Ground Reaction Force ◽  
Knee Flexion ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Ankle Dorsiflexion ◽  
Initial Contact ◽  
Vertical Ground Reaction Force ◽  
Recreational Athletes ◽  
Restricted Group ◽  
Vertical Ground

Context: Ankle dorsiflexion range of motion (DF ROM) has been associated with a number of kinematic and kinetic variables associated with landing performance that increase injury risk. However, whether exercise-induced fatigue exacerbates compensatory strategies has not yet been established. Objectives: (1) Explore differences in landing performance between individuals with restricted and normal ankle DF ROM and (2) identify the effect of fatigue on compensations in landing strategies for individuals with restricted and normal ankle DF ROM. Design: Cross-sectional. Setting: University research laboratory. Patients or Other Participants: Twelve recreational athletes with restricted ankle DF ROM (restricted group) and 12 recreational athletes with normal ankle DF ROM (normal group). Main Outcome Measure(s): The participants performed 5 bilateral drop-landings, before and following a fatiguing protocol. Normalized peak vertical ground reaction force, time to peak vertical ground reaction force, and loading rate were calculated, alongside sagittal plane initial contact angles, peak angles, and joint displacement for the ankle, knee, and hip. Frontal plane projection angles were also calculated. Results: At the baseline, the restricted group landed with significantly less knee flexion (P = .005, effect size [ES] = 1.27) at initial contact and reduced peak ankle dorsiflexion (P < .001, ES = 1.67), knee flexion (P < .001, ES = 2.18), and hip-flexion (P = .033, ES = 0.93) angles. Sagittal plane joint displacement was also significantly less for the restricted group for the ankle (P < .001, ES = 1.78), knee (P < .001, ES = 1.78), and hip (P = .028, ES = 0.96) joints. Conclusions: These findings suggest that individuals with restricted ankle DF ROM should adopt different landing strategies than those with normal ankle DF ROM. This is exacerbated when fatigued, although the functional consequences of fatigue on landing mechanics in individuals with ankle DF ROM restriction are unclear.

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