Comparison of lower limb segment forces during running on artificial turf and natural grass

Introduction: Artificial turf, soon after being introduced in the 1980s, became associated with an increased injury incidence in football players. While more recent generations of artificial turf have mitigated the problem, perception of the material is still widely negative. So, the decision to play the 2015 Fe'de'ration Internationale de Football Association Women s World Cup in Canada on artificial turf was met with vocal criticism by many players. One common approach is to assess injury incidence to quantify risk differences in playing surfaces. This, however, does not account for possible confounding variables or chronic injuries. Direct measurement of ground reaction forces is difficult because conventional multicamera-based motion capture and force plate equipment are limited in its use outside of dedicated laboratories. Methods: We describe a method of generating realistic force data by using miniature load cells that are installed directly into the weight-bearing structure of the body. Results: Pilot data show a significant (p<0.01) difference in peak forces on artificial turf (272% of body weight) and natural grass (229% of body weight). Discussion: Invasive surgical procedures were avoided by installing the load cell into the prosthesis of an athlete with lower limb loss. As modern prosthetic devices allow a close approximation of able-bodied kinematics and kinetics, such prosthesis-based data are transferable to a general population.

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Anticipatory weight shift between arms when reaching from a crouched posture

Journal of Neurophysiology ◽

10.1152/jn.00644.2020 ◽

2021 ◽

Author(s):

Rosemary Gallagher ◽

Stephaine Perez ◽

Derek DeLuca ◽

Isaac L. Kurtzer

Keyword(s):

Body Weight ◽

Muscle Activity ◽

Force Plate ◽

Vertical Axis ◽

The Body ◽

Reaching Movements ◽

Reactive Control ◽

Step Initiation ◽

Weight Shift ◽

The Many

Reaching movements performed from a crouched body posture require a shift of body weight from both arms to one arm. This situation has remained unexamined despite the analogous load requirements during step initiation and the many studies of reaching from a seated or standing posture. To determine whether the body weight shift involves anticipatory or exclusively reactive control we obtained force plate records, hand kinematics, and arm muscle activity from 11 healthy right-handed participants. They performed reaching movements with their left and right arm in two speed contexts - 'comfortable' and 'as fast as possible' - and two postural contexts - a less stable knees-together posture and more stable knees-apart posture. Weight-shifts involved anticipatory postural actions (APA) by the reaching and stance arms that were opposing in the vertical axis and aligned in the side-to-side axis similar to APAs by the legs for step initiation. Weight-shift APAs were correlated in time and magnitude, present in both speed contexts, more vigorous with the knees placed together, and similar when reaching with the dominant or non-dominant arm. The initial weight-shift was preceded by bursts of muscle activity in the shoulder and elbow extensors (posterior deltoid and triceps lateral) of the reach arm and shoulder flexor (pectoralis major) of the stance arm which indicates their causal role; leg muscles may have indirectly contributed but were not recorded. The strong functional similarity of weight-shift APAs during crouched reaching to human stepping and cats reaching suggests that they are a core feature of posture-movement coordination.

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A gravity balance mechanism used to eliminate the body-weight influence on people with lower-limb disabilities

Technology and Disability ◽

10.3233/tad-2011-0308 ◽

2011 ◽

Vol 23 (1) ◽

pp. 19-28 ◽

Cited By ~ 1

Author(s):

Pi-Ying Cheng ◽

Kuei-Jen Cheng

Keyword(s):

Body Weight ◽

Lower Limb ◽

The Body ◽

Balance Mechanism

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Lower Limb Human Muscle Enhancer

10.1115/imece2001/dsc-24620 ◽

2001 ◽

Author(s):

Joseph J. Misuraca ◽

Constantinos Mavroidis

Keyword(s):

Lower Limb ◽

Weight Bearing ◽

Kinematic Chain ◽

Human Muscle ◽

The Body ◽

Knee Joints ◽

Lower Body ◽

Loop Control ◽

Test Fixture ◽

Leg Muscles

Abstract This paper describes the design, control, and testing of a Human Muscle Enhancer (HME) system that will augment the muscle capabilities of subjects requiring partial lower-limb weight-bearing gait support. The HME described in this paper is a pneumatically actuated quick connecting exoskeleton system that attaches to the foot and hip area of the body, thus “closing” the lower body kinematic chain. Control of the system is achieved by using encoders at the knee joints and Myo-Pneumatic (MP) Sensors implanted into the shoes and outer garments of the human. To test this design concept, a lower body exoskeleton test fixture has been fabricated. The test fixture mimics the human leg with the top cylinder providing the body weight on the leg. Another cylinder acts as leg muscles to provide the adjustable human reaction of the leg. Preliminary open and closed loop control tests have been performed that demonstate the capability of controlling the HME using the MP sensors.

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Prediction of pathological fracture in patients with metastatic disease of the lower limb

Scientific Reports ◽

10.1038/s41598-019-50636-9 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 7

Author(s):

Emma L. Howard ◽

Paul Cool ◽

Gillian L. Cribb

Keyword(s):

Body Weight ◽

Metastatic Disease ◽

Lower Limb ◽

Prospective Observational Study ◽

Pathological Fracture ◽

Weight Bearing ◽

Total Body Weight ◽

Threshold Level ◽

Total Body ◽

Optimum Threshold

Abstract The aim of this study was to investigate if the risk of pathological fracture can be predicted with the proportion of body weight that can be put through the affected leg in patients with metastatic bone disease of the lower limb. A prospective observational study was conducted in patients with metastatic disease in the lower limb. Receiver Operator Characteristic curves were used to identify the optimum threshold level of single stance weight bearing to predict fracture and compared to the Mirels score. Patients who underwent surgery could weight bear significantly less than those who did not have surgical intervention. The optimum threshold to predict pathological fracture was 85% of total body weight. No patient below the threshold level of 85% single stance body weight sustained a pathological fracture. The use of single stance body weight can be a useful in conjunction with the Mirels score to predict pathological fracture. If less than 85% of total body weight can be put through the affected limb, the risk of fracture increases, and consideration of treatment is suggested.

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Injury Surveillance in Major League Soccer: A 4-Year Comparison of Injury on Natural Grass Versus Artificial Turf Field

The American Journal of Sports Medicine ◽

10.1177/0363546519860522 ◽

2019 ◽

Vol 47 (10) ◽

pp. 2279-2286 ◽

Cited By ~ 2

Author(s):

Sean P. Calloway ◽

David M. Hardin ◽

Matthew D. Crawford ◽

J. Michael Hardin ◽

Lawrence J. Lemak ◽

...

Keyword(s):

Incidence Rate ◽

Ankle Injury ◽

Injury Incidence ◽

Artificial Turf ◽

Natural Grass ◽

Injury Data ◽

Major League Soccer ◽

Foot Injury ◽

Major League ◽

Elite Level

Background: Artificial playing surfaces are becoming more common due to decreased cost of maintenance and increased field usability across different environmental conditions. The Fédération Internationale de Football Association (FIFA) has approved newer generation artificial turf for soccer competition at the elite level, but many elite-level athletes prefer to play on natural grass surfaces due to a perceived increase in injury rate, discomfort, and fatigability on artificial turf. Hypothesis: Injury rates and rates of individually categorized types of injury experienced on artificial turf are noninferior to rates of injury on the standard comparator, natural grass, in elite-level Major League Soccer athletes. Study Design: Cohort study; Level of evidence, 2. Methods: Over the course of 4 Major League Soccer seasons (2013-2016), athlete injury data were recorded electronically. Injury data recorded in matches between 2 Major League Soccer teams were then analyzed. Playing surface was known for each venue, and all artificial turf surfaces were rated as 2-star according to FIFA criteria. Incidence rate ratios (Artificial Turf ÷ Natural Grass) were calculated with a 95% CI (α = .05) for both overall injury incidence and individual injury subgroups. A noninferiority margin (δ) of 0.15 was used to determine noninferiority of injury incidence rates. Results: A total of 2174 in-game injuries were recorded during the study period, with 1.54 injuries per game on artificial turf and 1.49 injuries per game on natural grass (incidence rate ratio, 1.033; 95% CI, 0.937-1.139). Within injury subgroups, overall ankle injury, Achilles injury, and ankle fracture were found to have a statistically higher incidence on artificial turf. Artificial turf was found to be noninferior to natural grass for overall foot injury and forefoot injury. No statistically significant differences were found in knee injuries between the 2 surfaces. Conclusion: The overall rate of injury on artificial turf was noninferior to that on natural grass. Within individual injury categories, a higher rate of ankle injury was found on artificial turf. No other injury subgroup demonstrated statistically significant differences between surfaces. Clinical Relevance: FIFA 2-star rated artificial turf is a viable alternative to natural grass in elite-level soccer competition. Innovative research methods for comparing artificial turf versus natural grass may elucidate relative advantages with respect to player safety.

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The Effect Of Playing Surface On Anterior Cruciate Ligament Injury In NCAA Soccer

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120s00125 ◽

2020 ◽

Vol 8 (3_suppl2) ◽

pp. 2325967120S0012

Author(s):

Mark Howard ◽

Hyunwoo Paco Kang ◽

Samantha Solaru ◽

Alexander E. Weber ◽

Mark F. Rick C

Keyword(s):

Anterior Cruciate Ligament ◽

Cruciate Ligament ◽

Acl Injury ◽

Soccer Players ◽

Injury Incidence ◽

Artificial Turf ◽

Acl Injuries ◽

Natural Grass ◽

Significant Difference ◽

Anterior Cruciate

Objectives: Previous orthopaedic literature has examined the effect of synthetic playing surfaces on the risk of anterior cruciate ligament (ACL) injury in athletes and produced varying and inconclusive results. The objective of this study was to examine the role of playing surface on the incidence and risk of ACL injury in collegiate soccer athletes. Methods: The NCAA Injury Surveillance Program (ISP) database was queried for ACL injuries for male and female soccer players from the 2004-05 through the 2013-14 seasons at all levels of competition. The number of athlete exposures (AEs), defined as 1 athlete participating in 1 practice or competition in which they were exposed to the possibility of athletic injury, were recorded for grass and synthetic playing surfaces. Both the reported injuries and exposures provided were weighted in order to represent the entire NCAA collegiate soccer population. Normalized ACL incidence rates were calculated as well as 95% confidence intervals (95%CI). Rate ratios comparing competition type amongst both competition and practice were calculated. Results: ACL injuries were more common on grass surfaces (1.16 per 10,000 AEs, 95%CI 1.12-1.20) than artificial turf (0.92 per 10,000 AEs, 95%CI 0.84-1.04). This difference was statistically significant (IRR 1.26, p<0.0001), and driven primarily by the difference in injury incidence during practice. The injury incidence during practice on natural grass (1.18 per 10,000 AEs, 95% CI 1.11-1.26) was significantly greater than the injury incidence rate during practice on artificial turf (0.067 per 10,000 AEs, 95%CI 0.043-0.096). Players were 17.7 times more likely (95%CI 10.6678-27.2187, p<0.0001) to sustain an ACL injury during practice on natural grass when compared to practice on artificial turf. However, there was no significant difference in injury incidence during matches (IRR 0.96, p=0.44), with matches on natural grass (3.35 per 10,000 AEs, 95% CI 3.21-3.51) equivalent to matches on artificial surfaces (3.49 per 10,000 AEs, 95%CI 3.18-3.81). When comparing exposure type, the injury rate was significantly greater during matches (3.38 per 10,000 AEs, 95% CI 3.25-3.52) compared to practices (0.82 per 10,000 AEs, 95%CI 0.77-0.88), with a 4.10-fold increase in ACL injury incidence during matches compared to practice (p<0.0001). Conclusion: Between 2004 and 2014, NCAA soccer players experienced a greater number of ACL injuries on natural grass playing surfaces compared with artificial turf playing surfaces. This difference is driven by injuries during practice, where athletes were nearly 18 times more likely to suffer an ACL injury on grass versus artificial turf. While ACL injuries were more likely during matches compared to practices, no difference in incidence was noted between playing surfaces. Additional study is warranted investigating potential causes for this observed increased risk with soccer practice on grass fields.

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Upper and lower limb loading during weight-bearing activity in children: reaction forces and influence of body weight

Journal of Sports Sciences ◽

10.1080/02640414.2017.1407438 ◽

2017 ◽

Vol 36 (14) ◽

pp. 1640-1647 ◽

Cited By ~ 1

Author(s):

M. C. Erlandson ◽

S. Hounjet ◽

T. Treen ◽

J. L. Lanovaz

Keyword(s):

Body Weight ◽

Lower Limb ◽

Weight Bearing ◽

Limb Loading ◽

Reaction Forces

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Body weight homeostat that regulates fat mass independently of leptin in rats and mice

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1715687114 ◽

2017 ◽

Vol 115 (2) ◽

pp. 427-432 ◽

Cited By ~ 36

Author(s):

John-Olov Jansson ◽

Vilborg Palsdottir ◽

Daniel A. Hägg ◽

Erik Schéle ◽

Suzanne L. Dickson ◽

...

Keyword(s):

Body Weight ◽

Fat Mass ◽

Weight Bearing ◽

The Body ◽

Bone Strain ◽

Body Fat Mass ◽

Feedback Systems ◽

Diet Induced Obesity ◽

Increased Risk ◽

Rats And Mice

Subjects spending much time sitting have increased risk of obesity but the mechanism for the antiobesity effect of standing is unknown. We hypothesized that there is a homeostatic regulation of body weight. We demonstrate that increased loading of rodents, achieved using capsules with different weights implanted in the abdomen or s.c. on the back, reversibly decreases the biological body weight via reduced food intake. Importantly, loading relieves diet-induced obesity and improves glucose tolerance. The identified homeostat for body weight regulates body fat mass independently of fat-derived leptin, revealing two independent negative feedback systems for fat mass regulation. It is known that osteocytes can sense changes in bone strain. In this study, the body weight-reducing effect of increased loading was lost in mice depleted of osteocytes. We propose that increased body weight activates a sensor dependent on osteocytes of the weight-bearing bones. This induces an afferent signal, which reduces body weight. These findings demonstrate a leptin-independent body weight homeostat (“gravitostat”) that regulates fat mass.

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Sliding and Lower Limb Mechanics during Sit-Stand-Sit Transitions with a Standing Wheelchair

BioMed Research International ◽

10.1155/2014/236486 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8

Author(s):

Yu-Sheng Yang ◽

Ming-De Chen ◽

Wei-Chien Fang ◽

Jyh-Jong Chang ◽

Chang-Chih Kuo

Keyword(s):

Body Weight ◽

Range Of Motion ◽

Lower Limb ◽

Careful Consideration ◽

The Body ◽

Shear Displacement ◽

Standing Up ◽

Resultant Forces

Purpose.This study aimed to investigate the shear displacement between the body and backrest/seat, range of motion (ROM), and force acting on the lower limb joints during sit-stand-sit transitions by operating an electric-powered standing wheelchair.Methods and Materials.The amounts of sliding along the backrest and the seat plane, ROM of lower limb joints, and force acting on the knee/foot were measured in twenty-four people with paraplegia.Results.Without an antishear mechanism, the shear displacement was approximately 9 cm between the user’s body and the backrest/seat surfaces. During standing up, the user’s back slid down and the thigh was displaced rearward, but they moved in opposite directions when wheelchair sat back down. A minimum of 60 degrees of ROM at the hip and knee was needed during sit-stand-sit transitions. The maximal resultant forces acting on the knee restraints could reach 23.5% of body weight.Conclusion.Sliding between the body and backrest/seat occurred while transitioning from sitting to standing and vice versa. A certain amount of ROM at lower limb joints and force acting on the knee was necessitated during sit-stand-sit transitions. Careful consideration needs to be given to who the user of the electric powered standing wheelchair is.

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