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 Plantar Tactile Feedback for Biped Balance and Locomotion on Unknown Terrain

2020 ◽  
Vol 17 (01) ◽  
pp. 1950036 ◽  
Author(s):  
J. Rogelio Guadarrama Olvera ◽  
Emmanuel Dean Leon ◽  
Florian Bergner ◽  
Gordon Cheng
Keyword(s):  
Center Of Pressure ◽  
Tactile Feedback ◽  
Ground Reaction Forces ◽  
Biped Robots ◽  
Sensing System ◽  
Sensing Technology ◽  
Precise Shape ◽  
Reaction Forces ◽  
Resultant Forces ◽  
Robot Skin

This work introduces a new sensing system for biped robots based on plantar robot skin, which provides not only the resultant forces applied on the ankles but a precise shape of the pressure distribution in the sole together with other extra sensing modalities (temperature, pre-touch and acceleration). The information provided by the plantar robot skin can be used to compute the center of pressure and the ground reaction forces. This information also enables the online construction of the supporting polygon and its preemptive shape before foot landing using the proximity sensors in the robot skin. Two experiments were designed to show the advantages of this new sensing technology for improving balance and walking controllers for biped robots over unknown terrain.

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.

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.

Foot-Landing Style Effects on Vertical Ground Reaction Forces and Proximal Anterior Tibial Shear Forces

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S24
Author(s):  
James A. Onate ◽  
Nelson Cortes ◽  
Joao Abrantes ◽  
Linda Gagen ◽  
Bonnie Van Lunen ◽  
...  
Keyword(s):  
Ground Reaction Forces ◽  
Shear Forces ◽  
Anterior Tibial ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces

Peak forelimb ground reaction forces experienced by dogs jumping from a simulated car boot

2018 ◽  
Vol 182 (25) ◽  
pp. 716-716 ◽  
Author(s):  
David Pardey ◽  
Gillian Tabor ◽  
James Andrew Oxley ◽  
Alison P Wills
Keyword(s):  
Injury Risk ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Significant Difference ◽  
Reaction Forces ◽  
Repeated Analysis ◽  
Single Force ◽  
Vertical Ground ◽  
Post Hoc ◽  
The Relationship

Many dog owners allow their pets to jump out of a car boot; however, to date, there has been no study that has investigated whether this places dogs at risk of injury. The aim of this study was to investigate the relationship between height and peak vertical ground reaction force (vGRF) in static start jumps. Fifteen healthy adult dogs performed three jumps from a platform that represented common vehicle boot sill heights (0.55, 0.65, 0.75 m), landing on a single force platform. Kinetic data (mediolateral (Fx), craniocaudal (Fy) and vertical (Fz)) were normalised for body weight and analysed via a one-way repeated analysis of variance (ANOVA) and pairwise post hoc tests with a Bonferroni correction applied. There was a significant difference in peak forelimb vGRF between both the 0.55 m (27.35±4.14 N/kg) and the 0.65 m (30.84±3.66 N/kg) platform (P=0.001) and between the 0.65 and 0.75 m (34.12±3.63 N/kg) platform (P=0.001). There was no significant difference in mediolateral or craniocaudal forces between the heights examined. These results suggest that allowing dogs to jump from bigger cars with a higher boot sill may result in augmented levels of loading on anatomical structures. Further research is required to investigate the kinematic effects of height on static jump-down and how peak forelimb vGRF relates to anatomical loading and subsequent injury risk.

scholarly journals An Endurance-Dominated Exercise Program Improves Maximum Oxygen Consumption, Ground Reaction Forces, and Muscle Activities in Patients With Moderate Diabetic Neuropathy

2021 ◽  
Vol 12 ◽  
Author(s):  
AmirAli Jafarnezhadgero ◽  
Elahe Mamashli ◽  
Urs Granacher
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Exercise Program ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Significant Group ◽  
Heel Contact ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Post Hoc

BackgroundThe prevalence of diabetes worldwide is predicted to increase from 2.8% in 2000 to 4.4% in 2030. Diabetic neuropathy (DN) is associated with damage to nerve glial cells, their axons, and endothelial cells leading to impaired function and mobility.ObjectiveWe aimed to examine the effects of an endurance-dominated exercise program on maximum oxygen consumption (VO2max), ground reaction forces, and muscle activities during walking in patients with moderate DN.MethodsSixty male and female individuals aged 45–65 years with DN were randomly assigned to an intervention (IG, n = 30) or a waiting control (CON, n = 30) group. The research protocol of this study was registered with the Local Clinical Trial Organization (IRCT20200201046326N1). IG conducted an endurance-dominated exercise program including exercises on a bike ergometer and gait therapy. The progressive intervention program lasted 12 weeks with three sessions per week, each 40–55 min. CON received the same treatment as IG after the post-tests. Pre- and post-training, VO2max was tested during a graded exercise test using spiroergometry. In addition, ground reaction forces and lower limbs muscle activities were recorded while walking at a constant speed of ∼1 m/s.ResultsNo statistically significant baseline between group differences was observed for all analyzed variables. Significant group-by-time interactions were found for VO2max (p &lt; 0.001; d = 1.22). The post-hoc test revealed a significant increase in IG (p &lt; 0.001; d = 1.88) but not CON. Significant group-by-time interactions were observed for peak lateral and vertical ground reaction forces during heel contact and peak vertical ground reaction force during push-off (p = 0.001–0.037; d = 0.56–1.53). For IG, post-hoc analyses showed decreases in peak lateral (p &lt; 0.001; d = 1.33) and vertical (p = 0.004; d = 0.55) ground reaction forces during heel contact and increases in peak vertical ground reaction force during push-off (p &lt; 0.001; d = 0.92). In terms of muscle activity, significant group-by-time interactions were found for vastus lateralis and gluteus medius during the loading phase and for vastus medialis during the mid-stance phase, and gastrocnemius medialis during the push-off phase (p = 0.001–0.044; d = 0.54–0.81). Post-hoc tests indicated significant intervention-related increases in vastus lateralis (p = 0.001; d = 1.08) and gluteus medius (p = 0.008; d = 0.67) during the loading phase and vastus medialis activity during mid-stance (p = 0.001; d = 0.86). In addition, post-hoc tests showed decreases in gastrocnemius medialis during the push-off phase in IG only (p &lt; 0.001; d = 1.28).ConclusionsThis study demonstrated that an endurance-dominated exercise program has the potential to improve VO2max and diabetes-related abnormal gait in patients with DN. The observed decreases in peak vertical ground reaction force during the heel contact of walking could be due to increased vastus lateralis and gluteus medius activities during the loading phase. Accordingly, we recommend to implement endurance-dominated exercise programs in type 2 diabetic patients because it is feasible, safe and effective by improving aerobic capacity and gait characteristics.

scholarly journals Lower Extremity Stiffness in Collegiate Distance Runners Pre- and Post-Competition

2020 ◽  
Vol 71 (1) ◽  
pp. 69-77
Author(s):  
Jake P. Tavernite ◽  
Matthew F. Moran
Keyword(s):  
Ground Reaction Forces ◽  
Distance Runners ◽  
Countermovement Jump ◽  
Squat Jump ◽  
Leg Stiffness ◽  
Main Effect ◽  
Before And After ◽  
Reaction Forces ◽  
Cross Country ◽  
Post Hoc

AbstractPrevious evidence has suggested that there is a relationship between leg stiffness and improved running performance. The purpose of this investigation was to determine how leg stiffness of runners was influenced in the 24 and 48 hour period following a cross country race. Twenty-two collegiate cross-country runners (13 males, 9 females, 19.5 ± 1.4 yr) were recruited and participated in the study. Leg stiffness was assessed 24 hours before and after a race as well as 48 hours post-race. Three jumping protocols were conducted: 1) a static jump, 2) a countermovement jump, and 3) a vertical hopping test. Two embedded force plates (1000 Hz) were utilized to measure ground reaction forces for each test and a metronome was utilized to maintain hopping frequency (2.2 Hz). A significant main effect was found for a static jump, a countermovement jump and leg stiffness. Leg stiffness was significantly reduced 24 hours post-race (pre-race 36.84 kN·m-1, 24h post 33.11 kN·m-1, p < 0.05), but not 48 hours post-race (36.30 kN·m-1). No significant differences were found in post-hoc analysis for the squat jump, countermovement jump height and the eccentric utilization ratio. Following a cross-country race, leg stiffness significantly declined in a group of collegiate runners in the immediate 24 hours post-race, but returned to baseline 48 hours post-race. Sport scientists and running coaches may be able to monitor leg stiffness as a metric to properly prescribe training regiments.

Examination of the Feasibility of a 2-Dimensional Portable Assessment of Knee Joint Stability: A Pilot Study

2020 ◽  
Vol 36 (6) ◽  
pp. 381-389
Author(s):  
Ryan Zerega ◽  
Carolyn Killelea ◽  
Justin Losciale ◽  
Mallory Faherty ◽  
Timothy Sell
Keyword(s):  
Knee Joint ◽  
Knee Flexion ◽  
Injury Risk ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Initial Contact ◽  
Ground Reaction Forces ◽  
Joint Stability ◽  
Reaction Forces ◽  
Acl Injury Risk

Rupture of the anterior cruciate ligament (ACL) remains extremely common, with over 250,000 injuries annually. Currently, clinical tests have poor utility to accurately screen for ACL injury risk in athletes. In this study, the position of a knee marker was tracked in 2-dimensional planes to predict biomechanical variables associated with ACL injury risk. Three-dimensional kinematics and ground reaction forces were collected during bilateral, single-leg stop-jump tasks for 44 healthy male military personnel. Knee marker position data were extracted to construct 2-dimensional 95% prediction ellipses in each anatomical plane. Knee marker variables included: ellipse areas, major/minor axes lengths, orientation of ellipse axes, absolute ranges of knee position, and medial knee collapse. These variables were then used as predictor variables in stepwise multiple linear regression analyses for 7 biomechanical variables associated with ACL injury risk. Knee flexion excursion, normalized peak vertical ground reaction forces, and knee flexion angle at initial contact were the response variables that generated the highest adjusted R2 values: .71, .37, and .31, respectively. The results of this study provide initial support for the hypothesis that tracking a single marker during 2-dimensional analysis can accurately reflect the information gathered from 3-dimensional motion analysis during a task assessing knee joint stability.

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