Suchergebnisse

A promising option for preventing ankle sprains during sports training is a series of exercises based on the ankle disc training approach (Parkkari, 2001). The mechanism of action of these exercises (referred to as 'stability training') is poorly understood. A biomechanical analysis on the role of the various components of the lower limb including muscles, tendons and ligaments in stabilizing the ankle may provide insight into the mechanism of action. There is little point in conducting a complex and costly biomechanical analysis, however, if stability training cannot be integrated into established sports training programme. The purpose of this pilot study was to asses the feasibility of integrating stability training in recruit training in the New Zealand Defence Force. Recruit training is ideal because it has a high incidence of ankle injuries and is done in a controlled environment. This is a work in progress; the long term aim is to test the effectiveness of stability training in both military and high-risk sports environments using randomised controlled trials.

We are all grateful to Professor Jerry Barham for his work in assembling this conference. Those of us at UNC value greatly his professional work and appreciate his effort in bringing this international symposium to Colorado. As a young university, this institution is especially gratified to host such a distinguished event. This session of the 3rd International Symposium on Biomechanics in Sport allows me to sketch for you a brief history of the kinesiology program--as it is called at the University of Northern Colorado. As you might expect, the preparation for this presentation gave me the opportunity to learn more about the history of the program. I have my suspicions that there are some internal political purposes behind this invitation--to know and better appreciate the program--but that is all well and good. Too seldom do administrators in a university have the opportunity to learn in detail the history of a program and a field. As you know, on most campuses we central administrators are supposedly confined to some tower from which we send edicts--at least that is the mythology. In fact, we are often trapped by demands placed on us by external constituencies such as legislatures and super boards. We came into academia in order to serve our own intellectual interests and ultimately to serve the intellectual interests of our faculty colleagues. And that remains the case for virtually all of us. However, we are often to be found warring over policies imposed and policies to be developed than we are looking at the intellectual aspects of one of the disciplines in the university. For all those reasons, I am pleased to be here and to join you for a little while.

Pushing and pulling tasks are increasingly prevalent in industrial workplaces. Few studies have investigated low-back biomechanical risk factors associated with pushing, and we are aware of none that has quantified spinal stability during pushing exertions. Data recorded from 11 healthy participants performing isometric pushing exertions demonstrated that trunk posture, vector force direction of the applied load, and trunk moment were influenced (p < .01) by exertion level, elevation of the handle for the pushing task, and foot position. A biomechanical model was used to analyze the posture and hand force data gathered from the pushing exertions. Model results indicate that pushing exertions provide significantly (p < .01) less stability than lifting when antagonistic cocontraction is ignored. However, stability can be augmented by recruitment of muscle cocontraction. Results suggest that cocontraction may be recruited to compensate for the fact that equilibrium mechanics provide little intrinsic trunk stiffness and stability during pushing exertions. If one maintains stability by means of cocontraction, additional spinal load is thereby created, increasing the risk of overload injury. Thus it is important to consider muscle cocontraction when evaluating the biomechanics of pushing exertions. Potential applications of this research include improved assessment of biomechanical risk factors for the design of industrial pushing tasks.

Yi Wang, Muguo Song, Yongqing Xu, Xiaoqing He, YueLiang Zhu Department of Orthopedic Surgery, Kunming General Hospital, Chengdu Military Command, People's Liberation Army, Kunming, Yunnan, People's Republic of China Background: The scaphoid is critical for maintaining the stability and movement of the wrist joints. This study aimed to develop a new internal fixator absorbable scaphoid screw (ASS) for fixation of the scaphoid waist after fracture and to test the biomechanical characteristics of ASS.Materials and methods: An ASS was prepared using polylactic acids and designed based on scaphoid measurements and anatomic features. Twenty fractured scaphoid waist specimens were randomly divided into experimental and control groups (n=10/group). Reduction and internal fixation of the scaphoid were achieved with either Kirschner wires (K-wires) or ASS. A moving target simulator was used to test palmar flexion and dorsal extension, with the range of testing (waist movement) set from 5° of palmar flexion to 25° of dorsal extension. Flexion and extension were repeated 2,000 times for each specimen. Fracture gap displacements were measured with a computerized tomography scanning. Scaphoid tensile and bending strengths were measured by using a hydraulic pressure biomechanical system.Results: Prior to biomechanical fatigue testing, fracture gap displacements were 0.16±0.02 mm and 0.22±0.02 mm in the ASS and K-wire groups, respectively. After fatigue testing, fracture gap displacements in the ASS and the K-wire groups were 0.21±0.03 mm and 1.52±0.07 mm, respectively. The tensile strengths for the ASS and K-wire groups were 0.95±0.02 MPa and 0.63±0.02 MPa, respectively.Conclusion: Fixation using an ASS provided sufficient mechanical support for the scaphoid after fracture. Keywords: absorbable scaphoid screw, biomechanics, internal fixator, Kirschner wires

Phenomenon This study aimed to investigate how students can develop their understanding of trauma biomechanics by means of technology-enhanced learning-an interactive visualization tool developed to enhance understanding of the biomechanics underlying an injury via dynamic imaging sequences. Approach: Students were invited to explore the content as a learning resource during an interprofessional clinical placement on an orthopedic ward. Thirty volunteer medical, nursing, and physiotherapy/occupational therapy students participated in 10 interprofessional groups of three participants. They were video recorded while interacting with learning software that was divided into five sections: Work Up, General Information, Biomechanical Case Study, Biomechanical Risk Assessment, and Treatment. Investigators probed students learning experiences via four focus group discussions. A sociomaterial perspective was adopted, directing the analytical focus to how students made use of talk, gestures, bodies, and material objects to understand the visualized phenomena. Findings: When connecting the visualization to a patient case, certain features of the technology stood out as important for promoting engagement and understanding trauma mechanisms. Decreased tempo, showing the directions and dynamics of trauma biomechanics in slow-motion, and color coding of the strain on the affected structures were especially important for evoking the emotional responses. The visualization tool also supported students explorations of causal relationships between external forces and their biomedical effects. These features emphasize the sociomaterial relation between the design of the technology and the student activities. Insights: Dynamic visualization of biomechanical events has the potential to improve the understanding of injury mechanisms and specifically to identify anatomical structures at high risk of injury. Dynamic visualizations for educational purposes seem to promote possibilities for learners to contextualize visual representations relative to ones own body. Educational methods and practice need explicit attention and development in order to use the full potential of the visualization technology for learning for the health care professions. ; Funding Agencies|Marcus and Amalia Wallenberg Foundation, Sweden [MAW2014-0103]; Stockholm County CouncilStockholm County Council [20150760]

The Virginia Tech-Wake Forest University Center for Injury Biomechanics (CIB) has completed 10 years of research in the fields of automobile safety, military restraints, and sports biomechanics. The CIB has grown to include 74 researchers lead by 10 faculty and 48 staff and student researchers. These researchers examine human tolerance across a range of dynamic loading environments for all body regions. The CIB is the largest university based injury biomechanics research group in the world. It includes five separate laboratory facilities with over 40,000 sq. ft. of dedicated research space. The faculty and staff have published nearly 300 journal and refereed conference papers in 10 general research areas. The objective of this paper is to summarize briefly the CIB research capabilities and accomplishments.

Numerous studies have been conducted to investigate golf swing performance in both preventing injury and injury occurrence. The objective of this review was to describe state-of-the-art golf swing biomechanics, with a specific emphasis on movement kinematics, and when possible, to suggest recommendations for research methodologies. Keywords related to biomechanics and golf swings were used in scientific databases. Only articles that focused on golf-swing kinematics were considered. In this review, 92 articles were considered and categorized into the following domains: X-factor, crunch factor, swing plane and clubhead trajectory, kinematic sequence, and joint angular kinematics. The main subjects of focus were male golfers. Performance parameters were searched for, but the lack of methodological consensus prevented generalization of the results and led to contradictory results. Currently, three-dimensional approaches are commonly used for joint angular kinematic investigations. However, recommendations by the International Society of Biomechanics are rarely considered.

Although much has been learned in recent decades about the deterioration of muscular strength, gait adaptations, and sensory degradation among older adults, little is known about how these intrinsic changes affect biomechanical parameters associated with slip-induced fall accidents. In general, the objective of this laboratory study was to investigate the process of initiation, detection, and recovery of inadvertent slips and falls. We examined the initiation of and recovery from foot slips among three age groups utilizing biomechanical parameters, muscle strength, and sensory measurements. Forty-two young, middle-age, and older participants walked around a walking track at a comfortable pace. Slippery floor surfaces were placed on the track over force platforms at random intervals without the participants' awareness. Results indicated that younger participants slipped as often as the older participants, suggesting that the likelihood of slip initiation is similar across all age groups; however, older individuals? recovery process was much slower and less effective. The ability to successfully recover from a slip (thus preventing a fall) is believed to be affected by lower extremity muscle strength and sensory degradation among older individuals. Results from this research can help pinpoint possible intervention strategies for improving dynamic equilibrium among older adults.

Background: This study determined whether prolonged load carriage increased the magnitude and velocity of knee adduction biomechanics and whether increases were related to knee varus thrust or alignment. Methods: Seventeen participants (eight varus thrust and nine control) had knee adduction quantified during 60-min of walking (1.3 m/s) with three body-borne loads (0 kg, 15 kg, and 30 kg). Magnitude, average and maximum velocity, and time to peak of knee adduction biomechanics were submitted to a mixed model ANOVA. Results: With the 0 and 15 kg loads, varus thrust participants exhibited greater magnitude (p ≤ 0.037, 1.9–2.3°), and average (p ≤ 0.027, up to 60%) and maximum velocity (p ≤ 0.030, up to 44%) of varus thrust than control, but differences were not observed with the 30 kg load. The 15 and 30 kg loads led to significant increases in magnitude (p ≤ 0.017, 15–25%) and maximum velocity (p ≤ 0.017, 11–20%) of knee adduction moment, while participants increased magnitude (p ≤ 0.043, up to 0.3°) and maximum velocity (p ≤ 0.022, up to 5.9°/s and 6.7°/s) for knee adduction angle and varus thrust at minutes 30 and 60. Static alignment did not differ between groups (p = 0.412). Conclusion: During prolonged load carriage, all participants increased the magnitude and velocity of knee adduction biomechanics and the potential risk of knee OA.

AbstractThe form–function conceptual framework, which assumes a strong relationship between the structure of a particular trait and its function, has been crucial for understanding morphological variation and locomotion among extant and fossil species across many disciplines. In biological anthropology, it is the lens through which many important questions and hypotheses have been tackled with respect to relationships between morphology and locomotor kinematics, energetics and performance. However, it is becoming increasingly evident that the morphologies of fossil hominins, apes and humans can confer considerable locomotor diversity and flexibility, and can do so with a range of kinematics depending on soft tissue plasticity and environmental and cultural factors. This complexity is not built into traditional biomechanical or mathematical models of relationships between structure and kinematics or energetics, limiting our interpretation of what bone structure is telling us about behaviour in the past. The nine papers presented in this Special Collection together address some of the challenges thatvariationin the relationship between form and function pose in evolutionary biomechanics, to better characterise the complexity linking structure and function and to provide tools through which we may begin to incorporate some of this complexity into our functional interpretations.

Limited research exists in the literature regarding the biomechanics of the jump-landing sequence in individuals that experience symptoms of muscle damage. The present study investigated the effects of knee localized muscle damage on sagittal plane landing biomechanics during drop vertical jump (DVJ). Thirteen regional level athletes performed five sets of 15 maximal eccentric voluntary contractions of the knee extensors of both legs at 60°/s. Pelvic and lower body kinematics and kinetics were measured pre- and 48 h post-eccentric exercise. The examination of muscle damage indicators included isometric torque, muscle soreness, and serum creatine kinase (CK) activity. The results revealed that all indicators changed significantly following eccentric exercise (p < 0.05). Peak knee and hip joint flexion as well as peak anterior pelvic tilt significantly increased, whereas vertical ground reaction force (GRF), internal knee extension moment, and knee joint stiffness significantly decreased during landing (p < 0.05). Therefore, the participants displayed a softer landing pattern following knee-localized eccentric exercise while being in a muscle-damaged state. This observation provides new insights on how the DVJ landing kinematics and kinetics alter to compensate the impaired function of the knee extensors following exercise-induced muscle damage (EIMD) and residual muscle soreness 48 h post-exercise.

The SB Charité I artificial disc was developed in 1982 by Schellnack and Büttner-Janz and modified as the Mark II version in 1984. Both types were manufactured in the former German Democratic Republic (GDR). Today's design, the SB Charité III, was first produced by LINK in 1987. Five sizes of the artificial disc in various angulations are available today, with a double coating of titanium/calciumphosphate. Designed with a three-component set-up, the SB Charité mimics the physiological segmental motion. The possibility of translation in the SB Charité provides proper biomechanical function and protects the zygapophysial joints. Results of biomechanical testing showed a sufficient cold-flow resistance of the UHMWPE (Ultra High Molecular Weight Polyethylene) sliding core and confirmed the negligible abrasion rate. The LINK SB Charité disc is a safe and effective operative treatment for discogenic low back pain. Long-term results (10 years and more) have been published.