scholarly journals Lower Limbs Joint Loading – Case Study

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Miloš Petrović
Keyword(s):  
Lower Limb ◽  
Lower Limbs ◽  
Return To Play ◽  
Joint Loading ◽  
Performance Tasks ◽  
Biomechanical Assessment ◽  
Motion System ◽  
Tracking Motion ◽  
Loading Case ◽  
Reaction Forces

Injury prevention plays an important role in modern sport. The most commonly injured joint in male and female football players is the knee joint. It has been reported that approximately 60-85% of football injuries occur in the lower limbs. The aim of this study is to present the methods of biomechanical assessment of lower limbs joint loading during specific tasks (single leg squat (SLS) and single leg landing (SLL)). In this experimental setup, Qualisys Tracking Motion system synchronised with AMTII force plates embedded into the floor was used. The marker setup Salford Lower Limb model was used to track pelvis and lower body movements. By analysing biomechanical parameters (range of motion, internal moments, power, ground reaction forces) in all three planes it is possible to identify the structures and the imbalances of the lower extremity that need intervention and further decrease the possibility of injury to the knee and to evaluate an appropriate moment of return to play. This method showed a very high reproducibility and it can be considered as a reliable tool in assessing lower limb performance tasks.

The Effects of Uni- and Bilateral Fatigue on Postural and Power Tasks

2013 ◽  
Vol 29 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Paulo H. Marchetti ◽  
Maria I.V. Orselli ◽  
Marcos Duarte
Keyword(s):  
Lower Limb ◽  
Healthy Subjects ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Lower Limbs ◽  
Quiet Standing ◽  
Ground Reaction Forces ◽  
Before And After ◽  
Reaction Forces ◽  
The Mean

The aim of this study was to investigate the effects of unilateral and bilateral fatigue on both postural and power bipedal tasks. Ten healthy subjects performed two tasks: bipedal quiet standing and a maximal bipedal counter-movement jumping before and after unilateral (with either the dominant or nondominant lower limb) and bilateral (with both lower limbs) fatigue. We employed two force plates (one under each lower limb) to measure the ground reaction forces and center of pressure produced by subjects during the tasks. To quantify the postural sway during quiet standing, we calculated the resultant center of pressure (COP) speed and COP area of sway, as well as the mean weight distribution between lower limbs. To quantify the performance during the countermovement jumping, we calculated the jump height and the peak force of each lower limb. We observed that both unilateral and bilateral fatigue affected the performance of maximal voluntary jumping and standing tasks and that the effects of unilateral and bilateral fatigue were stronger in the dominant limb than in the nondominant limb during bipedal tasks. We conclude that unilateral neuromuscular fatigue affects both postural and power tasks negatively.

scholarly journals How does the ski boot affect human gait and joint loading?

2021 ◽  
Vol 13 (1) ◽  
pp. 163-169
Author(s):  
Karol Lann vel Lace ◽  
Michalina Błażkiewicz
Keyword(s):  
Lower Limb ◽  
Kinetic Data ◽  
Musculoskeletal Model ◽  
Lower Limbs ◽  
Human Gait ◽  
Hip Joints ◽  
Joint Reaction Forces ◽  
Reaction Forces ◽  
Anybody Modeling System ◽  
Muscle Torques

Abstract Study aim: To investigate the effect of wearing ski boots on kinematic and kinetic parameters of lower limbs during gait. Furthermore, loads in lower limb joints were assessed using the musculoskeletal model. Material and methods: The study examined 10 healthy women with shoe size 40 (EUR). Kinematic and kinetic data of walking in ski boots and barefoot were collected using a Vicon system and Kistler plates. A musculoskeletal model derived from AnyBody Modeling System was used to calculate joint reaction forces. Results: Wearing ski boots caused the range of motion in the knee joint to be significantly smaller and the hip joint to be significantly larger. Muscle torques were significantly greater in walking in ski boots for the knee and hip joints. Wearing ski boots reduced the reaction forces in the lower limb joints by 18% for the ankle, 16% for the knee, and 39% for the hip. Conclusions: Ski boot causes changes in the ranges of angles in the lower limb joints and increases muscle torques in the knee and hip joints but it does not increase the load on the joints. Walking in a ski boot is not destructive in terms of forces acting in the lower limb joints.

Determination of lower limbs loading during balance beam exercise

2020 ◽  
Author(s):  
Petr Hedbávný ◽  
Miriam Kalichová ◽  
Michal Rabenseifner ◽  
Adam Borek
Keyword(s):  
Lower Limb ◽  
Reaction Force ◽  
The Other ◽  
Lower Limbs ◽  
Balance Beam ◽  
Video Recordings ◽  
Maximum Reaction ◽  
Load Asymmetry ◽  
Load Volume ◽  
Reaction Forces

In women’s artistic gymnastics, the balance beam belongs among the disciplines with the heaviest lower limbs load. The aim of our research was to disclose a lower limbs weekly load volume regarding load asymmetry, and to determine the take-off and landing reaction forces between landing ground and foot in selected gymnastic elements. In 9 female artistic gymnasts of junior and senior category one training week was video-recorded and analysed. The reaction forces were measured using 5 Bertec force plates in one female Czech nation-al team member. Based on the training video recordings 12 jump and acrobatic elements were analysed. Among the total of 422 recorded take-offs and landings 41% were performed from both legs, (BL), 44.5% from one lower limb (HL) and 14.5% from the other lower limb (LL). The maximum reaction force of the landing ground during take-offs was 2.4 BW in av-erage, 3.1 BW in landings. In asymmetrical elements, one leg was loaded three times more (538.3 BW) than the other (174.1 BW) in one training day in total. We recommend to record the load asymmetry in the course of the gymnastic trainings in order to choose and person-alise the appropriate regeneration process and compensational exercise.

scholarly journals The role of the contralateral limb in below-knee amputee gait

1990 ◽  
Vol 14 (1) ◽  
pp. 33-42 ◽  
Author(s):  
G. R. B. Hurley ◽  
R. McKenney ◽  
M. Robinson ◽  
M. Zadravec ◽  
M. R. Pierrynowski
Keyword(s):  
Lower Limb ◽  
Reaction Force ◽  
Force Plate ◽  
Lower Limbs ◽  
Contralateral Limb ◽  
Joint Reaction Forces ◽  
Reaction Forces ◽  
Joint Reaction ◽  
Amputee Gait

Very little quantitative biomechanical research has been carried out evaluating issues relevant to prosthetic management. The literature available suggests that amputees may demonstrate an asymmetrical gait pattern. Furthermore, studies suggest that the forces occurring during amputee gait may be unequally distributed between the contralateral and prosthetic lower limbs/This study investigates the role of the contralateral limb in amputee gait by determining lower limb joint reaction forces and symmetry of motion in an amputee and non-amputee population. Seven adult below-knee amputees and four non-amputees participated in the study. Testing involved collection of kinematic coordinate data employing a WATSMART video system and ground reaction force data using a Kistler force plate. The degree of lower limb symmetry was determined using bilateral angle-angle diagrams and a chain encoding technique. Ankle, knee and hip joint reaction forces were estimated in order to evaluate the forces acting across the joints of the amputee's contralateral limb. The amputees demonstrated a lesser degree of lower limb symmetry than the non-amputees. This asymmetrical movement was attributed to the inherent variability of the actions of the prosthetic lower limb. The forces acting across the joints of the contralateral limb were not significantly higher than that of the non-amputee. This suggests that, providing the adult amputee has a good prosthetic fit, there will not be increased forces across the joints of the contralateral limb and consequently no predisposition for the long-term wearer to develop premature degenerative arthritis.

Design of a Human Knee Reeducation Mechanism

2019 ◽  
Vol 11 (1) ◽  
pp. 42-53
Author(s):  
Allaoua Brahmia ◽  
Ridha Kelaiaia
Keyword(s):  
Lower Limb ◽  
Mechanical Design ◽  
Kinematic Chain ◽  
Lower Limbs ◽  
Kinematic Structure ◽  
Robotic Device ◽  
Human Knee ◽  
Kinematic Study ◽  
Rehabilitation Exercise ◽  
New Machine

Abstract To establish an exercise in open muscular chain rehabilitation (OMC), it is necessary to choose the type of kinematic chain of the mechanical / biomechanical system that constitutes the lower limbs in interaction with the robotic device. Indeed, it’s accepted in biomechanics that a rehabilitation exercise in OMC of the lower limb is performed with a fixed hip and a free foot. Based on these findings, a kinematic structure of a new machine, named Reeduc-Knee, is proposed, and a mechanical design is carried out. The contribution of this work is not limited to the mechanical design of the Reeduc-Knee system. Indeed, to define the minimum parameterizing defining the configuration of the device relative to an absolute reference, a geometric and kinematic study is presented.

scholarly journals Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Time Patterns ◽  
Foot Strike ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

scholarly journals Effects of Dominant and Nondominant Limb Immobilization on Muscle Activation and Physical Demand during Ambulation with Axillary Crutches

2021 ◽  
Vol 6 (1) ◽  
pp. 16
Author(s):  
Kara B. Bellenfant ◽  
Gracie L. Robbins ◽  
Rebecca R. Rogers ◽  
Thomas J. Kopec ◽  
Christopher G. Ballmann
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Weight Bearing ◽  
Lower Limbs ◽  
Medial Gastrocnemius ◽  
Bipedal Walking ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Physical Demand ◽  
Limb Dominance

The purpose of this study was to investigate the effects of how limb dominance and joint immobilization alter markers of physical demand and muscle activation during ambulation with axillary crutches. In a crossover, counterbalanced study design, physically active females completed ambulation trials with three conditions: (1) bipedal walking (BW), (2) axillary crutch ambulation with their dominant limb (DOM), and (3) axillary crutch ambulation with their nondominant limb (NDOM). During the axillary crutch ambulation conditions, the non-weight-bearing knee joint was immobilized at a 30-degree flexion angle with a postoperative knee stabilizer. For each trial/condition, participants ambulated at 0.6, 0.8, and 1.0 mph for five minutes at each speed. Heart rate (HR) and rate of perceived exertion (RPE) were monitored throughout. Surface electromyography (sEMG) was used to record muscle activation of the medial gastrocnemius (MG), soleus (SOL), and tibialis anterior (TA) unilaterally on the weight-bearing limb. Biceps brachii (BB) and triceps brachii (TB) sEMG were measured bilaterally. sEMG signals for each immobilization condition were normalized to corresponding values for BW.HR (p < 0.001) and RPE (p < 0.001) were significantly higher for both the DOM and NDOM conditions compared to BW but no differences existed between the DOM and NDOM conditions (p > 0.05). No differences in lower limb muscle activation were noted for any muscles between the DOM and NDOM conditions (p > 0.05). Regardless of condition, BB activation ipsilateral to the ambulating limb was significantly lower during 0.6 mph (p = 0.005) and 0.8 mph (p = 0.016) compared to the same speeds for BB on the contralateral side. Contralateral TB activation was significantly higher during 0.6 mph compared to 0.8 mph (p = 0.009) and 1.0 mph (p = 0.029) irrespective of condition. In conclusion, limb dominance appears to not alter lower limb muscle activation and walking intensity while using axillary crutches. However, upper limb muscle activation was asymmetrical during axillary crutch use and largely dependent on speed. These results suggest that functional asymmetry may exist in upper limbs but not lower limbs during assistive device supported ambulation.

scholarly journals COVID-19 era in long-term cardiac rehabilitation programs: how was muscle strenght and lean mass affected in cardiovascular patients?

2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
M Borges ◽  
M Lemos Pires ◽  
R Pinto ◽  
G De Sa ◽  
I Ricardo ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Cardiac Rehabilitation ◽  
Lean Mass ◽  
Lower Limb ◽  
Lower Limbs ◽  
Phase Iii ◽  
Face To Face ◽  
Home Based ◽  
Lower Limb Strength

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Exercise prescription is one of the main components of phase III Cardiac Rehabilitation (CR) programs due to its documented prognostic benefits. It has been well established that, when added to aerobic training, resistance training (RT) leads to greater improvements in peripheral muscle strength and muscle mass in patients with cardiovascular disease (CVD). With COVID-19, most centre-based CR programs had to be suspended and CR patients had to readjust their RT program to a home-based model where weight training was more difficult to perform. How COVID-19 Era impacted lean mass and muscle strength in trained CVD patients who were attending long-term CR programs has yet to be discussed. Purpose To assess upper and lower limb muscle strength and lean mass in CVD patients who had their centre-based CR program suspended due to COVID-19 and compare it with previous assessments. Methods 87 CVD patients (mean age 62.9 ± 9.1, 82.8% male), before COVID-19, were attending a phase III centre-based CR program 3x/week and were evaluated annually. After 7 months of suspension, 57.5% (n = 50) patients returned to the face-to-face CR program. Despite all constraints caused by COVID-19, body composition and muscle strength of 35 participants (mean age 64.7 ± 7.9, 88.6% male) were assessed. We compared this assessment with previous years and established three assessment time points: M1) one year before COVID-19 (2018); M2) last assessment before COVID-19 (2019); M3) the assessment 7 months after CR program suspension (last trimester of 2020). Upper limbs strength was measured using a JAMAR dynamometer, 30 second chair stand test (number of repetitions – reps) was used to measure lower limbs strength and dual energy x-ray absorptiometry was used to measure upper and lower limbs lean mass. Repeated measures ANOVA were used. Results Intention to treat analysis showed that upper and lower limbs lean mass did not change from M1 to M2 but decreased significantly from M2 to M3 (arms lean mass in M2: 5.68 ± 1.00kg vs M3: 5.52 ± 1.06kg, p = 0.004; legs lean mass in M2: 17.40 ± 2.46kg vs M3: 16.77 ± 2.61kg, p = 0.040). Lower limb strength also decreased significantly from M2 to M3 (M2: 23.31 ± 5.76 reps vs M3: 21.11 ± 5.31 reps, p = 0.014) after remaining stable in the year prior to COVID-19. Upper limb strength improved significantly from M1 to M2 (M1: 39.00 ± 8.64kg vs M2: 40.53 ± 8.77kg, p = 0.034) but did not change significantly from M2 to M3 (M2 vs M3: 41.29 ± 9.13kg, p = 0.517). Conclusion After CR centre-based suspension due to COVID-19, we observed a decrease in upper and lower limbs lean mass and lower limb strength in previously trained CVD patients. These results should emphasize the need to promote all efforts to maintain physical activity and RT through alternative effective home-based CR programs when face-to-face models are not available or possible to be implemented.

Computed tomography angiography and microsurgical flaps for traumatic wounds: What is the added value?

2021 ◽  
pp. 1-9
Author(s):  
Lucas Sousa Macedo ◽  
Renato Polese Rusig ◽  
Gustavo Bersani Silva ◽  
Alvaro Baik Cho ◽  
Teng Hsiang Wei ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Upper Limb ◽  
Computed Tomography Angiography ◽  
Lower Limb ◽  
High Energy ◽  
Lower Limbs ◽  
Added Value ◽  
Vascular Lesions ◽  
Limb Injuries ◽  
Significant Difference

BACKGROUND: Microsurgical flaps are widely used to treat complex traumatic wounds of upper and lower limbs. Few studies have evaluated whether the vascular changes in preoperative computed tomography angiography (CTA) influence the selection of recipient vessel and type of anastomosis and the microsurgical flaps outcomes including complications. OBJECTIVE: The aim of this study was to evaluate if preoperative CTA reduces the occurrence of major complications (revision of the anastomosis, partial or total flap failure, and amputation) of the flaps in upper and lower limb trauma, and to describe and analyze the vascular lesions of the group with CTA and its relationship with complications. METHODS: A retrospective cohort study was undertaken with all 121 consecutive patients submitted to microsurgical flaps for traumatic lower and upper limb, from 2014 to 2020. Patients were divided into two groups: patients with preoperative CTA (CTA+) and patients not submitted to CTA (CTA–). The presence of postoperative complications was assessed and, within CTA+, we also analyzed the number of patent arteries on CTA and described the arterial lesions. RESULTS: Of the 121 flaps evaluated (84 in the lower limb and 37 in the upper limb), 64 patients underwent preoperative CTA. In the CTA+ group, 56% of patients with free flaps for lower limb had complete occlusion of one artery. CTA+ patients had a higher rate of complications (p = 0.031), which may represent a selection bias as the most complex limb injuries and may have CTA indicated more frequently. The highest rate of complications was observed in chronic cases (p = 0.034). There was no statistically significant difference in complications in patients with preoperative vascular injury or the number of patent arteries. CONCLUSIONS: CTA should not be performed routinely, however, CTA may help in surgical planning, especially in complex cases of high-energy and chronic cases, since it provides information on the best recipient artery and the adequate level to perform the microanastomosis, outside the lesion area.

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