Analysis of Foot-Ankle-Leg Injuries in Various Under-Foot Impact Loading Environments with a Human Active Lower Limb (HALL) Model

2021 ◽  
Author(s):  
Jing Huang ◽  
Can Huang ◽  
Fuhao Mo
Keyword(s):  
Impact Loading ◽  
Lower Limb ◽  
Loading Rate ◽  
External Rotation ◽  
Loading Conditions ◽  
Leg Injuries ◽  
Limb Injuries ◽  
Foot Loading ◽  
Definition Of ◽  
Neutral Posture

Abstract Lower limb injuries caused by under-foot impacts often appear in sport landing, automobile collision, and anti-vehicular landmine blasts. The purpose of the present study was to evaluate a foot-ankle-leg model of the Human Active Lower Limb (HALL) model, and used it to investigate lower leg injury responses in different under-foot loading environments to provide a theoretical basis for the design of physical dummies adapted to multiple loading conditions. The model was first validated in allowable rotation loading conditions, like dorsiflexion, inversion/eversion, and external rotation. Then, its sensitivity to loading rates and initial postures was further verified through experimental data concerning both biomechanical stiffness and injury locations. Finally, the model was used to investigate the biomechanical responses of the foot-ankle-leg region in different under-foot loading conditions covering the loading rate from sport landing to blast impact. The results showed that from -15° plantarflexion to 30° dorsiflexion, the neutral posture always showed the largest tolerance, and more than 1.5 times tolerance gap was achieved between neutral posture and dorsiflexion 30°. Under-foot impacts from 2 m/s to 14 m/s, the peak tibia force increased at least 1.9 times in all postures. Thus, we consider that it is necessary to include initial posture and loading rate factors in the definition of the foot-ankle-leg injury tolerance for under-foot impact loading.

scholarly journals Effectiveness of Insole Colour on Impact Loading and Lower-Limb Kinematics When Running at Preferred and Nonpreferred Speeds

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yi Wang ◽  
Wing-Kai Lam ◽  
Lok-Yee Pak ◽  
Charis K.-W. Wong ◽  
Mohammad F. Tan ◽  
...  
Keyword(s):  
Impact Loading ◽  
Ground Reaction Force ◽  
Lower Limb ◽  
Repeated Measures ◽  
Loading Rate ◽  
Reaction Force ◽  
Human Perception ◽  
Movement Variability ◽  
Mean Values ◽  
Maximum Loading

While colour of red can play a significant role in altering human perception and performances, little is known about its perceptual-motor effect on running mechanics. This study examined the effects of variations in insole colours on impact forces, ankle kinematics, and trial-to-trial reliability at various running speeds. Sixteen male recreational runners ran on instrumented treadmill at slow (90%), preferred (100%), and fast (110%) running speeds when wearing insoles in red, blue, and white colours. We used synchronized force platform and motion capturing system to measure ground reaction force, ankle sagittal and frontal kinematics, and movement variability. A two-way (colour x speed) ANOVA with repeated measures was performed with Bonferroni adjusted post hoc comparisons, with alpha set at 0.05. Data analyses indicated that participants demonstrated higher impact and maximum loading rate of ground reaction force, longer stride length, shorter contact time, and smaller touchdown ankle inversion as well as larger ankle sagittal range of motion (RoM), but smaller frontal RoM in fast speed as compared with preferred P < 0.05 and slow speeds P < 0.001 . Although insole colour had minimal effect on mean values of any tested variables P > 0.05 , participants wearing red-coloured orthoses showed higher coefficient of variation values for maximum loading rate than wearing blue insoles P = 0.009 . These results suggest that running at faster speed would lead to higher impact loading and altered lower-limb mechanics and that colour used on the tops of insoles influences the wearers’ movement repeatability, with implications for use of foot insole in running.

scholarly journals Lower Limb and Trunk Biomechanics After Fatigue in Competitive Female Irish Dancers

2017 ◽  
Vol 52 (7) ◽  
pp. 643-648 ◽  
Author(s):  
Catherine Y. Wild ◽  
Avril Grealish ◽  
Diana Hopper
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Plantar Flexion ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Limb Injuries ◽  
Before And After ◽  
Joint Reaction Forces ◽  
Reaction Forces ◽  
Trunk Biomechanics

Context:  Because of the increasing popularity of participation in Irish dance, the incidence of lower limb injuries is high among this competitive population. Objective:  To investigate the effects of fatigue on the peak lower limb and trunk angles as well as the peak lower limb joint forces and moments of competitive female Irish dancers during the performance of a dance-specific single-limb landing. Design:  Cross-sectional study. Setting:  Laboratory. Patients or Other Participants:  Fourteen healthy, female, competitive Irish dancers (age = 19.4 ± 3.7 years, height = 165.3 ± 5.9 cm, mass = 57.9 ± 8.2 kg). Intervention(s):  Participants performed an Irish dance–specific leap before and after a dance-specific fatigue protocol. During each landing movement, 3-dimensional lower limb kinematics (250 Hz) and ground reaction forces (1000 Hz) were collected. Paired t tests were performed to determine the differences (P ≤ .05) in lower limb and trunk biomechanics prefatigue and postfatigue. Main Outcome Measure(s):  Peak lower limb and trunk angles as well as peak lower limb joint reaction forces and external moments. Results:  Compared with the prefatigue trials, dancers landed with reduced ankle plantar flexion (P = .003) and hip external rotation (P = .007) and increased hip-adduction alignment (P = .034) postfatigue. Dancers displayed greater anterior shear (P = .003) and compressive (P = .024) forces at the ankle and greater external knee-flexion moments (P = .024) during the postfatigue compared with the prefatigue landing trials. Conclusions:  When fatigued, dancers displayed a decline in landing performance in terms of aesthetics as well as increased ankle- and knee-joint loading, potentially exposing them to a greater risk of injuries.

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.

scholarly journals Reliability of a New Portable Dynamometer for Assessing Hip and Lower Limb Strength

2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Peak Torque ◽  
Knee Extension ◽  
Lower Limb Muscles ◽  
Lower Limb Strength ◽  
Flexion Extension ◽  
Strength Tests ◽  
Hip Abduction ◽  
Maximal Peak

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.

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