Evaluation of Lower Limb Injury Mitigation Techniques for High Velocity Impacts With the Mil-LX

2011 ◽  
Author(s):  
Jennifer L. Serres ◽  
Dan V. Jones ◽  
Rabih E. Tannous ◽  
Nathan Dau ◽  
Cynthia A. Bir
Keyword(s):  
Lower Extremity ◽  
Lower Limb ◽  
Axial Loading ◽  
Critical Factor ◽  
Lower Limbs ◽  
Lower Limb Injury ◽  
Lower Extremity Injuries ◽  
Axial Forces ◽  
Limb Injuries ◽  
Mitigation Techniques

Improvised Explosive Devices (IED) and landmines present a significant threat to mounted troops currently serving in Iraq and Afghanistan. As a result of these threats, a substantial number of lower limb injuries are sustained by service members. Due to this reality, a critical factor in military vehicle design is the mitigation of lower limb trauma. Past studies have shown that the standard Hybrid III and THOR-LX are not biofidelic in military axial loading conditions (up to 12 m/s). Both of these surrogates over predict axial forces compared to Post Mortem Human Specimens (PMHS) [1]. As a result, a new surrogate was developed, Mil-LX (Military Lower Extremity), that matches the PMHS response for axial loading of the lower leg up to 12 m/s [2,3]. While injury mitigation techniques, such as energy absorbing mats, foot rests, and isolation floors, have been effective in reducing lower extremity injuries in live fire test events, there are several variants of each of these methods. Additionally, it has also been suggested that the positioning of the lower limbs may affect the load sustained by these extremities [4].

Ankle–foot orthosis alignment affects running mechanics in individuals with lower limb injuries

2019 ◽  
Vol 43 (3) ◽  
pp. 316-324
Author(s):  
Kelly A Schmidtbauer ◽  
E Russell Esposito ◽  
Jason M Wilken
Keyword(s):  
Lower Extremity ◽  
Lower Limb ◽  
Knee Extensor ◽  
Design Parameters ◽  
Foot Orthoses ◽  
Lower Limb Injury ◽  
Limb Injuries ◽  
Peak Knee ◽  
Ankle Foot Orthoses ◽  
Running Mechanics

Background: Individuals with severe lower extremity injuries often require ankle–foot orthoses to return to normal activities. Ankle–foot orthoses alignment is a key consideration during the clinical fitting process and may be particularly important during dynamic activities such as running. Objective: To investigate how 3° changes in sagittal plane ankle–foot orthoses alignment affect running mechanics. Study design: Controlled laboratory study. Methods: Twelve participants with unilateral lower limb injury ran overground and lower extremity running mechanics were assessed. Participants wore their passive-dynamic ankle–foot orthoses in three alignments: clinically fit neutral, 3° plantarflexed from clinically fit neutral, and 3° dorsiflexed from clinically fit neutral. Results: The 3° changes in sagittal alignment significantly influenced ankle mechanics during running. The plantarflexed alignment significantly decreased the peak ankle plantarflexor moment, peak knee extensor moment, and peak ankle and knee power absorption and generation compared to more dorsiflexed alignments. Alignment also altered footstrike angle, with dorsiflexed alignments associated with a more dorsiflexed footstrike pattern and plantarflexed alignments toward a more plantarflexed footstrike pattern. However, alignment did not influence loading rate. Conclusion: Small changes in ankle–foot orthoses alignment significantly altered running mechanics, including footstrike angle, and knee extensor moments. Understanding how ankle–foot orthoses design parameters affect running mechanics may aid the development of evidence-based prescription guidelines and improve function for ankle–foot orthoses users who perform high-impact activities. Clinical relevance Understanding how ankle–foot orthoses alignment impacts biomechanics should be a consideration when fitting passive-dynamic devices for higher impact activities, such as running. Individual running styles, including footstrike patterns, may be affected by small changes in alignment.

scholarly journals Exergaming and Static Postural Control in Individuals With a History of Lower Limb Injury

2013 ◽  
Vol 48 (3) ◽  
pp. 314-325 ◽  
Author(s):  
Jennifer Sims ◽  
Nicole Cosby ◽  
Ethan N. Saliba ◽  
Jay Hertel ◽  
Susan A. Saliba
Keyword(s):  
Lower Extremity ◽  
Postural Control ◽  
Lower Limb ◽  
Lower Limb Injury ◽  
Wii Fit ◽  
Limb Injury ◽  
Limb Injuries ◽  
Main Effect ◽  
History Of

Context: Therapeutic exercise programs that incorporate real-time feedback have been reported to enhance outcomes in patients with lower extremity joint injuries. The Wii Fit has been purported to improve balance, strength, flexibility, and fitness. Objective: To determine the effects of Wii Fit rehabilitation on postural control and self-reported function in patients with a history of lower limb injury. Design: Single-blinded, randomized controlled trial. Setting: Laboratory. Patients or Other Participants: Twenty-eight physically active participants with a history of lower limb injuries were randomly assigned to 1 of 3 groups (9 Wii Fit, 10 traditional, 9 control). Intervention(s): Intervention groups performed supervised rehabilitation 3 d/wk for a total of 12 sessions. Main Outcome Measure(s): Time to boundary (TTB) and the Star Excursion Balance Test (SEBT) were conducted at baseline, 2 weeks, and 4 weeks. Self-reported function was measured at baseline and 4-week follow-up. Between-groups differences were compared using repeated-measures multivariate analysis of variance. Results: With the eyes open, both intervention groups improved (P < .05) in the mean and the SD of the TTB anterior-posterior minima. In the eyes-closed condition, a time main effect (P < .05) for absolute TTB medial-lateral minima was observed. A time main effect was also noted in the posteromedial and posterolateral reach directions of the SEBT. When the scores for each group were pooled, improvement (P < .05) in self-reported function was demonstrated at 4-week follow-up. Conclusions: Rehabilitation using the Wii Fit and traditional exercises improved static postural control in patients with a history of lower extremity injury.

scholarly journals Military Exercises, Knee and Ankle Joint Position Sense, and Injury in Male Conscripts: A Pilot Study

2013 ◽  
Vol 48 (6) ◽  
pp. 790-796 ◽  
Author(s):  
Farshid Mohammadi ◽  
Kamran Azma ◽  
Iman Naseh ◽  
Reza Emadifard ◽  
Yasaman Etemadi
Keyword(s):  
Lower Extremity ◽  
Lower Limb ◽  
Position Sense ◽  
Joint Position Sense ◽  
Joint Position ◽  
Lower Limb Injuries ◽  
Lower Extremity Injuries ◽  
Military Exercises ◽  
Limb Injuries ◽  
Extremity Injuries

Context: The high incidence of lower limb injuries associated with physical exercises in military conscripts suggests that fatigue may be a risk factor for injuries. Researchers have hypothesized that lower limb injuries may be related to altered ankle and knee joint position sense (JPS) due to fatigue. Objective: To evaluate if military exercises could alter JPS and to examine the possible relation of JPS to future lower extremity injuries in military service. Design: Cohort study. Setting: Laboratory. Patients or Other Participants: A total of 50 male conscripts (age = 21.4 ± 2.3 years, height = 174.5 ± 6.4 cm, mass = 73.1 ± 6.3 kg) from a unique military base were recruited randomly. Main Outcome Measure(s): Participants performed 8 weeks of physical activities at the beginning of a military course. In the first part of the study, we instructed participants to recognize predetermined positions before and after military exercises so we could examine the effects of military exercise on JPS. The averages of the absolute error and the variable error of 3 trials were recorded. We collected data on the frequency of lower extremity injuries over 8 weeks. Next, the participants were divided into 2 groups: injured and uninjured. Separate 2 × 2 × 2 (group-by-time-by-joint) mixed-model analyses of variance were used to determine main effects and interactions of these factors for each JPS measure. In the second part of the study, we examined whether the effects of fatigue on JPS were related to the development of injury during an 8-week training program. We calculated Hedges effect sizes for JPS changes postexercise in each group and compared change scores between groups. Results: We found group-by-time interactions for all JPS variables (F range = 2.86–4.05, P < .01). All participants showed increases in JPS errors postexercise (P < .01), but the injured group had greater changes for all the variables (P < .01). Conclusions: Military conscripts who sustained lower extremity injuries during an 8-week military exercise program had greater loss of JPS acuity than conscripts who did not sustain injuries. The changes in JPS found after 1 bout of exercise may have predictive ability for future musculoskeletal injuries.

scholarly journals Lower Extremity Risk Factors in Iranian Adolescent Taekwondo Players

2020 ◽  
Vol 10 (1) ◽  
pp. 7-14
Author(s):  
Mostafa Zarei ◽  
◽  
Kamran Johari ◽  
Rahim Bagherian ◽  
◽  
...  
Keyword(s):  
Risk Factors ◽  
Lower Extremity ◽  
Incidence Rate ◽  
Significant Relationship ◽  
Lower Limb ◽  
Adolescent Male ◽  
Injury Incidence ◽  
Lower Limb Injury ◽  
Q Angle ◽  
Limb Injuries

Purpose: Taekwondo is a martial art and contact sport in which the athletes’ goal is to strike the opponent with maximal force. This fact exposes taekwondo practitioners to the permanent risk of injuries. Therefore, the current prospective study aimed to investigate the internal risk factors of lower extremity injuries in the adolescent male taekwondo players. Methods: In total, 60 adolescent taekwondo players of Iran Premier League voluntarily participated in this research. Before league commencement, navicular drop, Q angle, knee hyperextension angle, the dorsiflexion/plantarflexion range of motion, hamstring flexibility, and their dynamic balance were measured. Then, the injuries of these taekwondo players were recorded during the study time. Results: The injury incidence rate was 7.9 per 1000 hours of exposure (95% confidence interval, 5.33-10.40). The logistic regression analysis data indicated a significant relationship between the Q angle and injuries incidence rate (odds ratio=1.33, P=0.031). The taekwondo players whose Q angles were >14.5 degrees were 1.33 times more prone to lower limb injury. However, no significant relationship was observed between the other risk factors of the study cases and injuries incidence.  Conclusion: Regarding the research findings, the Q angle could predict lower limb injuries in the studied taekwondo players. Therefore, it is suggested that this index be considered in the preparticipation evaluation process and preventive strategies. 

scholarly journals Effects of active muscle forces on driver’s lower-limb injuries due to emergency brake in various frontal impacts

2019 ◽  
Vol 234 (7) ◽  
pp. 2014-2024
Author(s):  
Fan Li ◽  
Wei Huang ◽  
Xingsheng Wang ◽  
Xiaojiang Lv ◽  
Fuhao Mo
Keyword(s):  
Muscle Contraction ◽  
Lower Limb ◽  
Injury Risk ◽  
Muscle Activation ◽  
Bending Moment ◽  
Lower Limbs ◽  
Lower Limb Injuries ◽  
Lower Limb Injury ◽  
Limb Injuries ◽  
The Impact

Accident data shows that driver’s kinematics response in real accidents can be significantly different from that in dummy or cadaver tests because of driver’s muscle contraction. In this study, a finite element human-body model consisting of an upper body of a dummy model and a lower limb–pelvis biomechanical model with three-dimensional active muscles was developed to investigate in depth the lower-limb injuries. Driver’s emergency reaction during frontal impact was simulated by modelling muscle active contraction based on a series of volunteer experimental tests. Besides, a realistic impact environment with the response of the restraint system and the invasion of the driver’s compartment was established in this study. The results show that muscle contraction can cause extra loads on lower limbs during the impact, which can increase the injury risk of lower limbs. As for the femur injury, muscle contraction caused an additional 1 kN axial load on the femur, and the femur resultant bending moment of active models was also higher by about 10–40 N m. Besides, the tibial index of the model with muscle activation was about 0.1 higher. In addition, the results indicate that the femur injury is strongly related to the combined action of both axial force and bending moment. The variation of the injury tolerance along the tibia shaft should be considered when evaluating the tibia injury. Overall, the current lower-limb injury criteria can be still the lack of robustness.

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.

A modern-day solution to a 100-yearold problem: the use of a bespoke offloading brace in the rehabilitation of ‘Deck-Slap’ and other high-energy lower limb injuries

2014 ◽  
Vol 100 (3) ◽  
pp. 337-343
Author(s):  
MA Osborne ◽  
HL Jarvis ◽  
N Bennett ◽  
RD Phillip
Keyword(s):  
Axial Loading ◽  
Cost Effective ◽  
Armed Forces ◽  
High Energy ◽  
Lower Limbs ◽  
Limb Amputation ◽  
Activity Levels ◽  
Prosthetic Devices ◽  
Functional Benefit ◽  
Limb Injuries

Abstract‘Deck-Slap’ is an injury pattern first described at the Battle of Jutland; it is still relevant today, with anti-vehicle mines a significant threat to Coalition troops. The effect of a device exploding beneath a vehicle produces a wave of high energy that is rapidly transmitted through the steel floor; this causes significant axial loading of lower limbs often resulting in severe fractures (notably of the calcaneum). Recent advancements in orthopaedic surgery have allowed for limbs that were destined for immediate amputation following significant trauma to be salvaged. However, despite intense rehabilitation, many of these salvaged limbs have subsequently gone on to delayed amputation, as functional outcomes are often poor. Technologically advanced prosthetic devices are available that afford good quality of life and allow for increased activity levels; these devices are, however, expensive to procure and maintain. This report describes a United Kingdom (UK) Armed Forces soldier who suffered a typical ‘deck-slap’ injury in Afghanistan with subsequent limb salvage. The use of the Bespoke Off-loading Brace (BOB) is discussed. The results presented here indicate that the biomechanical function of a patient with this type of injury improves when wearing the BOB. Further studies are needed to assess long-term clinical outcomes and the functional benefit of the device as a viable and cost-effective alternative to delayed limb amputation.

scholarly journals Risk factors for lower extremity injuries in young badminton players

2018 ◽  
Vol 28 (2) ◽  
pp. 28939
Author(s):  
Ang Lin Kang ◽  
Vinodhkumar Ramalingam
Keyword(s):  
Risk Factors ◽  
Lower Extremity ◽  
Limb Length Discrepancy ◽  
Ankle Injuries ◽  
Case Group ◽  
Lower Limb Injuries ◽  
Lower Extremity Injuries ◽  
Younger Age ◽  
Limb Injuries ◽  
Extremity Injuries

AIMS: Based on the limited evidence available about the intrinsic factors causing lower extremity injuries among Malaysian badminton players, this study was aimed to determine the relationship of demographic and physical characteristics to lower extremity injuries in young badminton players.METHODS: A cross-sectional study included badminton players between 14 and 24 years of age, categorized into case and control groups. Participants diagnosed with lower limb injuries were designated as cases, and those with no reported injuries were designated as controls. Personal information including demographic data, level of athlete and injury history was collected using a questionnaire. Independent t-test was used to analyze the differences between intrinsic characteristics in cases and controls. Pearson's χ2 was applied to evaluate the association between risk factors and general lower limb injuries, knee injuries and ankle injuries, with 95% confidence interval (CI). A p value of ≤0.05 was considered significant.RESULTS: A total of 106 young badminton players (83 males, 23 females) were recruited, of whom 42 participants were allocated as the case group, and 64 participants were allocated as the control group. A total of 60 lower extremity injuries were reported among the 42 players of the case group. The overall mean age of the sample was 18.7±5 years (minimum 14 years and maximum 24 years). Mean age of the participants in the case group was 16.92±2.99 years. The most common injuries reported were ankle joint injuries, followed by knee and hip injuries. Participants of the younger age group (14-19 years old) were found to have a higher risk for lower extremity injures compared to those of the older age group (20-24 years old) (odds ratio [OR], 3.39; 95%CI, 1.15-10.01; p=0.023). Increased true limb length discrepancy was identified among the participants with lower extremity injuries (OR, 4.57, 95%CI, 1.2-17.24; p=0.016) and this discrepancy was strongly associated with ankle injuries (OR, 7.25; 95%CI, 1.85-28.57; p=0.002). There was no significant relationship between lower extremity injuries and gender, limb dominance or Q-angle.CONCLUSIONS: Lower extremity injuries in young badminton players were predominantly located in ankle and knee joints. Younger age and increase in true limb length discrepancy were identified as risk factors for lower extremity injuries in the study sample.

scholarly journals Isolated Arteritis of Both Lower Limbs

2018 ◽  
Vol 119 (1) ◽  
pp. 70-75
Author(s):  
Miroslav Průcha ◽  
Alena Šnajdrová ◽  
Pavel Zdráhal
Keyword(s):  
Autoimmune Disease ◽  
Lower Extremity ◽  
Lower Limb ◽  
Imaging Techniques ◽  
Rare Condition ◽  
Rapid Diagnosis ◽  
Vascular Imaging ◽  
Lower Limbs ◽  
Systemic Autoimmune Disease ◽  
Successful Therapy

Isolated arteritis of the lower limb vessels is an extremely rare condition. The use of modern vascular imaging techniques substantially facilitates and accelerates the diagnostics. In the isolated lower limb arteritis, it is always necessary to exclude Takayasu’s and giant-cell arteritis. We present the case of a female patient with an isolated lower extremity arteritis without any other symptoms of systemic vascular damage or systemic autoimmune disease. Immunosuppressive therapy is obligatory in this case. Interdisciplinary co-operation is required for rapid diagnosis and successful therapy. Our patient has consented to the publication of this report.

Push recovery control for the underactuated lower extremity exoskeleton based on improved capture point concept

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jiaqi Zhang ◽  
Ming Cong ◽  
Dong Liu ◽  
Yu Du ◽  
Hongjiang Ma
Keyword(s):  
Lower Extremity ◽  
Ankle Joint ◽  
Lower Limb ◽  
Biped Robot ◽  
Lower Limbs ◽  
Simple Method ◽  
Content Type ◽  
Torsion Spring ◽  
Balance Ability ◽  
Capture Point

Purpose The purpose of this paper is to use a simple method to enhance the ability of lower limb exoskeletons to restore balance under large interference conditions and to solve the problem that biped robot stability criterion cannot be fully applied to the underactuated lower limb exoskeletons. Design/methodology/approach The method used in this paper is to construct an underactuated lower extremity exoskeleton ankle joint with a torsion spring. Based on the constructed exoskeleton, the linear inverted torsion spring pendulum model is proposed, and the traditional capture point (CP) concept is optimized. Findings The underactuated exoskeleton ankle joint with torsion springs, combined with the improved CP concept, can effectively reduce the forward stepping distance under the same interference condition, which is equivalent to enhancing the balance ability of the lower extremity exoskeleton. Originality/value The contribution of this paper is to enhance the balance ability of the exoskeleton of the lower limbs under large interference conditions. The torsion spring is used as the exoskeleton ankle joint, and the traditional CP concept is optimized according to the constructed exoskeleton.

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