scholarly journals Role of sex and stature on the biomechanics of normal and loaded walking: implications for injury risk in the military

2021 ◽  
pp. bmjmilitary-2020-001645
Author(s):  
Niamh Gill ◽  
A Roberts ◽  
T J O'Leary ◽  
A Liu ◽  
K Hollands ◽  
...  
Keyword(s):  
Injury Prevention ◽  
Injury Risk ◽  
Load Carriage ◽  
Ground Reaction Forces ◽  
Prevention Measures ◽  
Lower Limb Injury ◽  
Walking Gait ◽  
Transition Speed ◽  
Reaction Forces ◽  
The Military

Load carriage and marching ‘in-step’ are routine military activities associated with lower limb injury risk in service personnel. The fixed pace and stride length of marching typically vary from the preferred walking gait and may result in overstriding. Overstriding increases ground reaction forces and muscle forces. Women are more likely to overstride than men due to their shorter stature. These biomechanical responses to overstriding may be most pronounced when marching close to the preferred walk-to-run transition speed. Load carriage also affects walking gait and increases ground reaction forces, joint moments and the demands on the muscles. Few studies have examined the effects of sex and stature on the biomechanics of marching and load carriage; this evidence is required to inform injury prevention strategies, particularly with the full integration of women in some defence forces. This narrative review explores the effects of sex and stature on the biomechanics of unloaded and loaded marching at a fixed pace and evaluates the implications for injury risk. The knowledge gaps in the literature, and distinct lack of studies on women, are highlighted, and areas that need more research to support evidence-based injury prevention measures, especially for women in arduous military roles, are identified.

Center of Pressure, Vertical Ground Reaction Forces, and Neuromuscular Responses of Special-Forces Soldiers to 43-km Load Carriage in the Field

2020 ◽  
Vol 36 (5) ◽  
pp. 307-312
Author(s):  
James Scales ◽  
Jamie M. O’Driscoll ◽  
Damian Coleman ◽  
Dimitrios Giannoglou ◽  
Ioannis Gkougkoulis ◽  
...  
Keyword(s):  
Body Weight ◽  
Injury Risk ◽  
Center Of Pressure ◽  
Vertical Jump ◽  
Load Carriage ◽  
Ground Reaction Forces ◽  
Increased Risk ◽  
Heel Contact ◽  
Before And After ◽  
Reaction Forces

The primary purpose of this study was to examine lateral deviations in center of pressure as a result of an extreme-duration load carriage task, with particular focus on heel contact. A total of 20 (n = 17 males and n = 3 females) soldiers from a special operation forces unit (body mass 80.72 [21.49] kg, stature 178.25 [8.75] cm, age 26 [9] y) underwent gait plantar pressure assessment and vertical jump testing before and after a 43-km load carriage event (duration 817.02 [32.66] min) carrying a total external load of 29.80 (1.05) kg. Vertical jump height decreased by 18.62% (16.85%) from 0.30 (0.08) to 0.24 (0.07) m, P < .001. Loading peak and midstance force minimum were significantly increased after load carriage (2.59 [0.51] vs 2.81 [0.61] body weight, P = .035, Glass delta = 0.44 and 1.28 [0.40] vs 1.46 [0.41] body weight, P = .015, Glass delta = 0.45, respectively) and increases in lateral center of pressure displacement were observed as a result of the load carriage task 14.64 (3.62) to 16.97 (3.94) mm, P < .029. In conclusion, load carriage instigated a decrease in neuromuscular function alongside increases in ground reaction forces associated with injury risk and center of pressure changes associated with ankle sprain risk. Practitioners should consider that possible reductions in ankle stability remain once load carriage has been completed, suggesting soldiers are still at increased risk of injury even once the load has been removed.

The Effects of Posture and Technique on Forces Experienced When Hanging Continuous Miner Cable

1993 ◽  
Vol 37 (10) ◽  
pp. 779-783 ◽  
Author(s):  
Sean Gallagher ◽  
Christopher A. Hamrick ◽  
Mark S. Redfern
Keyword(s):  
Injury Risk ◽  
Underground Mines ◽  
Ground Reaction Forces ◽  
Shear Forces ◽  
Lateral Shear ◽  
Continuous Miner ◽  
Underground Coal Mines ◽  
Reaction Forces ◽  
Post Hoc ◽  
Resultant Forces

Analysis of lost-time back injuries in underground coal mines indicates that handling continuous miner cable places workers at high risk of injury. Manual hanging of this type of cable is a common lifting task in underground mines. This study was performed to assess the ground reaction forces associated with hanging cable in various postures and employing different methods of securing the cable. Seven experienced coal miners (mean age: 41.4 years ± 2.1) performed a series of 12 cable hanging tasks. Independent variables included a set of six posture/vertical space constraint conditions (LIFTCOND), and two techniques of securing the cable to the ceiling (METHOD). The dependent variables consisted of ground reaction forces measured using two force plates. LIFTCOND ( F5.66 = 21.31, p < 0.0001) and METHOD ( F1,66 = 10.89, p < 0.005) both significantly affected the magnitude of the peak resultant forces generated during the tasks. Post hoc analysis indicated that kneeling postures resulted in significantly lower forces than stooping for the same ceiling heights. Greater forces were associated with higher lifting conditions, attributable in part to the fact that higher lifts require more cable to be hoisted. Forces were also increased when subjects twisted baling wire to secure the cable, as compared to hanging it on a hook. An interaction between LIFTCOND and METHOD was identified with lateral shear forces - stooping conditions where the subjects twisted the cable with wire resulted in higher lateral shear forces. Results of this study will be used to develop recommendations to reduce back injury risk when handling cable.

scholarly journals An algorithm to decompose ground reaction forces and moments from a single force platform in walking gait

2014 ◽  
Vol 36 (11) ◽  
pp. 1530-1535 ◽  
Author(s):  
David Villeger ◽  
Antony Costes ◽  
Bruno Watier ◽  
Pierre Moretto
Keyword(s):  
Force Platform ◽  
Ground Reaction Forces ◽  
Walking Gait ◽  
Reaction Forces ◽  
Single Force

An Integrated Musculoskeletal-Finite-Element Model to Evaluate Effects of Load Carriage on the Tibia During Walking

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Chun Xu ◽  
Amy Silder ◽  
Ju Zhang ◽  
Julie Hughes ◽  
Ginu Unnikrishnan ◽  
...  
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Injury Risk ◽  
Load Carriage ◽  
Body Motion ◽  
Bone Biomechanics ◽  
External Loading ◽  
Fe Model ◽  
Loading Conditions ◽  
Reaction Forces

Prior studies have assessed the effects of load carriage on the tibia. Here, we expand on these studies and investigate the effects of load carriage on joint reaction forces (JRFs) and the resulting spatiotemporal stress/strain distributions in the tibia. Using full-body motion and ground reaction forces from a female subject, we computed joint and muscle forces during walking for four load carriage conditions. We applied these forces as physiological loading conditions in a finite-element (FE) analysis to compute strain and stress. We derived material properties from computed tomography (CT) images of a sex-, age-, and body mass index-matched subject using a mesh morphing and mapping algorithm, and used them within the FE model. Compared to walking with no load, the knee JRFs were the most sensitive to load carriage, increasing by as much as 26.2% when carrying a 30% of body weight (BW) load (ankle: 16.4% and hip: 19.0%). Moreover, our model revealed disproportionate increases in internal JRFs with increases in load carriage, suggesting a coordinated adjustment in the musculature functions in the lower extremity. FE results reflected the complex effects of spatially varying material properties distribution and muscular engagement on tibial biomechanics during walking. We observed high stresses on the anterior crest and the medial surface of the tibia at pushoff, whereas high cumulative stress during one walking cycle was more prominent in the medioposterior aspect of the tibia. Our findings reinforce the need to include: (1) physiologically accurate loading conditions when modeling healthy subjects undergoing short-term exercise training and (2) the duration of stress exposure when evaluating stress-fracture injury risk. As a fundamental step toward understanding the instantaneous effect of external loading, our study presents a means to assess the relationship between load carriage and bone biomechanics.

scholarly journals Utility of Kinetic and Kinematic Jumping and Landing Variables as Predictors of Injury Risk: A Systematic Review

2020 ◽  
Vol 2 (4) ◽  
pp. 287-304 ◽  
Author(s):  
Jason S. Pedley ◽  
Rhodri S. Lloyd ◽  
Paul J. Read ◽  
Isabel S. Moore ◽  
Mark De Ste Croix ◽  
...  
Keyword(s):  
Performance Measures ◽  
Injury Risk ◽  
Reaction Force ◽  
Separation Distance ◽  
Lower Extremity Injury ◽  
Ground Reaction Forces ◽  
Drop Jump ◽  
Jump Landing ◽  
Risk Of Injury ◽  
Reaction Forces

Abstract Purpose Jump-landing assessments provide a means to quantify an individual’s ability to attenuate ground reaction forces, generate lower limb explosive power and maintain joint alignment. In order to identify risk factors that can be targeted through appropriate training interventions, it is necessary to establish which (scalar) objective kinetic, kinematic, and performance measures are most associated with lower-extremity injury. Methods Online searches of MEDLINE, SCOPUS, EBSCOHost, SPORTDiscus and PubMed databases were completed for all articles published before March 2020 in accordance with PRISMA guidelines. Results 40 articles investigating nine jump-landing assessments were included in this review. The 79% of studies using drop jump (n = 14) observed an association with future injury, while only 8% of countermovement jump studies (n = 13) observed an association with injury risk. The 57% of studies using unilateral assessments found associations with risk of injury (n = 14). Studies using performance measures (jump height/distance) as outcome measure were only associated with injury risk in 30% of cases. However, those using kinetic and/or kinematic analyses (knee abduction moment, knee valgus angle, knee separation distance, peak ground reaction force) found associations with injury in 89% of studies. Conclusion The landing element of jump-landing assessments appears to be superior for identifying individuals at greater risk of injury; likely due to a closer representation of the injury mechanism. Consequently, jump-landing assessments that involve attenuation of impact forces such as the drop jump appear most suited for this purpose but should involve assessment of frontal plane knee motion and ground reaction forces.

scholarly journals Race Walking Ground Reaction Forces at Increasing Speeds: A Comparison with Walking and Running

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 873
Author(s):  
Gaspare Pavei ◽  
Dario Cazzola ◽  
Antonio La Torre ◽  
Alberto E. Minetti
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
The Body ◽  
Ground Reaction Forces ◽  
Centre Of Mass ◽  
Walking Gait ◽  
Wide Range ◽  
Reaction Forces ◽  
Race Walking ◽  
Walking Speeds

Race walking has been theoretically described as a walking gait in which no flight time is allowed and high travelling speed, comparable to running (3.6–4.2 m s−1), is achieved. The aim of this study was to mechanically understand such a “hybrid gait” by analysing the ground reaction forces (GRFs) generated in a wide range of race walking speeds, while comparing them to running and walking. Fifteen athletes race-walked on an instrumented walkway (4 m) and three-dimensional GRFs were recorded at 1000 Hz. Subjects were asked to performed three self-selected speeds corresponding to a low, medium and high speed. Peak forces increased with speeds and medio-lateral and braking peaks were higher than in walking and running, whereas the vertical peaks were higher than walking but lower than running. Vertical GRF traces showed two characteristic patterns: one resembling the “M-shape” of walking and the second characterised by a first peak and a subsequent plateau. These different patterns were not related to the athletes’ performance level. The analysis of the body centre of mass trajectory, which reaches its vertical minimum at mid-stance, showed that race walking should be considered a bouncing gait regardless of the presence or absence of a flight phase.

scholarly journals Prevention of sports injuries in children at school: a systematic review of policies

2018 ◽  
Vol 4 (1) ◽  
pp. e000346 ◽  
Author(s):  
Anya Göpfert ◽  
Maria Van Hove ◽  
Alan Emond ◽  
Julie Mytton
Keyword(s):  
Injury Prevention ◽  
Psychological Health ◽  
Injury Risk ◽  
Grey Literature ◽  
National Level ◽  
Evidence Base ◽  
Evidence Based ◽  
Prevention Measures ◽  
Framework Analysis ◽  
School Sports

BackgroundParticipation in sports as a child improves physical and psychological health. Schools need to promote sport while protecting against injury. It is not clear whether increasing evidence on injury prevention generated from professional sport is influencing school sports practices. This study reviewed policies promoting sport safety in schools to determine whether exposure to injury risk is recognised and whether evidence based prevention and management are included.MethodsA search strategy to identify policies for children aged 4–18 years was applied to electronic databases and grey literature sources. Safeguarding policies were excluded. Included policies were critically appraised and synthesised using modified framework analysis.ResultsTwenty-six policies were analysed. Most (57.7%) were from the USA. Ten (38.5%) focused solely on concussion. Synthesis identified primary, secondary and tertiary injury prevention measures relating to people (staff, students and parents), systems, school physical environment and national-level factors.ConclusionsRobust, evidence-based policies for reducing injury risk in school sports are limited. Guidelines with the largest evidence base were focused on concussion, with other school sport guidelines showing limited inclusion of evidence. Where included, evidence focused on injury management rather than prevention and frequently applied evidence from adult to children. Guidance was not specific to the child’s age, gender or developmental stage.

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