Characterization of Running Intensity in Canadian Football Based on Tactical Position.

This study aimed to use a data-driven approach to identify individualized speed thresholds to characterize running demands and athlete workload during games and practices in skill and linemen football players. Data were recorded from wearable sensors over 28 sessions from 30 male Canadian varsity football athletes, resulting in a total of 287 performances analyzed, including 137 games and 150 practices, using a global positioning system. Speed zones were identified for each performance by fitting a 5-dimensional Gaussian mixture model (GMM) corresponding to 5 running intensity zones from minimal (zone 1) to maximal (zone 5).

Concentrating to avoid falling: interaction between peripheral sensory and central attentional demands during a postural stability limit task in sedentary seniors.

Evidence suggests falls and postural instabilities among seniors are attributed to a decline in both the processing of afferent signals (e.g., proprioceptive, vestibular) and attentional resources.

Mediolateral Postural Control Mechanisms and Proprioception Improve With Kicking Sports Training During Adolescence.

Sensorimotor stimulation during the sensitive period is crucial for proper brain development. Kicking sports (KS) training stimulates these sensorimotor functions. The purpose of this study was to investigate if incorporating specific sensorimotor stimulation in mediolateral axis and proprioceptive inputs during KS training will improve the specific sensorimotor performance in adolescents.

A New Approach to Quantifying Muscular Fatigue Using Wearable EMG Sensors during Surgery: An Ergonomic Case Study.

(1) Background: Surgeons are exposed to musculoskeletal loads that are comparable to those of industrial workers. These stresses are harmful for the joints and muscles and can lead to musculoskeletal disorders (MSD) and working incapacity for surgeons. In this paper, we propose a novel ergonomic and visualization approach to assess muscular fatigue during surgical procedures.

A kinematic analysis of jumping technique in elite Korean teeterboard athletes: a case-study.

Korean teeterboard is a circus discipline that consists of a board pivoted at its centre upon which two acrobats are catapulted in turn performing acrobatic jumps. This paper presents one of the first studies that focuses on investigating the factors that contribute to jump height in Korean teeterboard. A total of 120 jumps were recorded from two acrobats using motion capture.

How Can Biomechanics Improve Physical Preparation and Performance in Paralympic Athletes? A Narrative Review.

Recent research in Paralympic biomechanics has offered opportunities for coaches, athletes, and sports practitioners to optimize training and performance, and recent systematic reviews have served to summarize the state of the evidence connecting biomechanics to Paralympic performance. This narrative review serves to provide a comprehensive and critical evaluation of the evidence related to biomechanics and Paralympic performance published since 2016. The main themes within this review focus on sport-specific body posture: the standing, sitting, and horizontal positions of current summer Paralympic sports.

Learned Overweight Internal Model Can Be Activated to Maintain Equilibrium When Tactile Cues Are Uncertain: Evidence From Cortical and Behavioral Approaches.

Human adaptive behavior in sensorimotor control is aimed to increase the confidence in feedforward mechanisms when sensory afferents are uncertain. It is thought that these feedforward mechanisms rely on predictions from internal models. We investigate whether the brain uses an internal model of physical laws (gravitational and inertial forces) to help estimate body equilibrium when tactile inputs from the foot sole are depressed by carrying extra weight.

Development of postural stability limits: Anteroposterior and mediolateral postural adjustment mechanisms do not follow the same maturation process.

There is increasing evidence that indicates a critical transition period for the maturation of postural control from the ages of 6-7 years. Some studies suggest that this transitional period may be explained by a change from a ballistic toward a sensory strategy, but the cause remains unknown. The purpose of this study was to investigate the influence of the transition period on dynamic postural control in a natural self-initiated leaning task under different sensory conditions.

Work-related musculoskeletal symptoms amongst Otolaryngologists and Head and Neck surgeons in Canada.

The first objective of this study was to identify work-related musculoskeletal symptoms and determine their prevalence in the practice of Otolaryngology and Head and Neck surgery in Canada. The second objective was to establish potential associations between those musculoskeletal symptoms and variables related to demographic status of the surgeons, their workload and work ergonomics. This study was designed as a Canadian census on work-related musculoskeletal symptoms amongst Otolaryngologist and Head and Neck surgeons.

Double-Blind, Placebo-Controlled, Randomized Phase I/IIa Study (Safety and Efficacy) with Buspirone/Levodopa/Carbidopa (SpinalonTM) in Subjects with Complete AIS A or Motor-Complete AIS B Spinal Cord Injury.

Background: No drug treatment capable of restoring locomotor capabilities in patients suffering a motor-complete spinal cord injury (SCI) has ever been developed. We assessed the safety and efficacy of an activator of spinal locomotor neurons in humans, which were shown in paraplegic animals to elicit temporary episodes of involuntary walking.

Methods: Single administration of buspirone/levodopa/carbidopa (SpinalonTM), levodopa/carbidopa (ratio 4: 1), and buspirone or placebo was performed using a dose-escalation design in 45 subjects placed in supine position who had had an SCI classified as complete (AIS A) or motor-complete/sensory incomplete (AIS B) for at least 3 months.

Impaired visually guided weight-shifting ability in children with cerebral palsy.

The ability to control voluntary weight shifting is crucial in many functional tasks. To our knowledge, weight shifting ability in response to a visual stimulus has never been evaluated in children with cerebral palsy (CP). The aim of the study was (1) to propose a new method to assess visually guided medio-lateral (M/L) weight shifting ability and (2) to compare weight-shifting ability in children with CP and typically developing (TD) children.

Balance, Falls-Related Self-Efficacy, and Psychological Factors amongst Older Women with Chronic Low Back Pain: A Preliminary Case-Control Study.

Objective. To investigate balance functions in older women and evaluate the association of the fear-avoidance beliefs model (FABM) factors with balance and mobility performance. Participants.

Hip joint center localisation: A biomechanical application to hip arthroplasty population.

Aim: To determine hip joint center (HJC) location on hip arthroplasty population comparing predictive and functional approaches with radiographic measurements.

Methods: The distance between the HJC and the mid-pelvis was calculated and compared between the three approaches. The localisation error between the predictive and functional approach was compared using the radiographic measurements as the reference.

Can one angle be simply subtracted from another to determine range of motion in three-dimensional motion analysis?

To determine the range of motion of a joint between an initial orientation and a final orientation, it is convenient to subtract initial joint angles from final joint angles, a method referred to as the vectorial approach. However, for three-dimensional movements, the vectorial approach is not mathematically correct. To determine the joint range of motion, the rotation matrix between the two orientations should be calculated, and angles describing the range of motion should be extracted from this matrix, a method referred to as the matrical approach.

Aging worsens the effects of sleep deprivation on postural control.

Falls increase with age and cause significant injuries in the elderly. This study aimed to determine whether age modulates the interactions between sleep deprivation and postural control and to evaluate how attention influences these interactions in the elderly. Fifteen young (24±2.

Center of Mass Compensation during Gait in Hip Arthroplasty Patients: Comparison between Large Diameter Head Total Hip Arthroplasty and Hip Resurfacing.

Objective. To compare center of mass (COM) compensation in the frontal and sagittal plane during gait in patients with large diameter head total hip arthroplasty (LDH-THA) and hip resurfacing (HR). Design.

Clinical validation of computer-assisted navigation in total hip arthroplasty.

A CT-based navigation system is helpful to evaluate the reamer shaft and the impactor position/orientation during unilateral total hip arthroplasty (THA). The main objective of this study is to determine the accuracy of the Navitrack system by measuring the implant's true anteversion and inclination, based on pre- and postoperative CT scans (n = 9 patients). The secondary objective is to evaluate the clinical validity of measurements based on postop anteroposterior (AP) radiographs for determining the cup orientation.

Effects of increased homeostatic sleep pressure on postural control and their modulation by attentional resources.

Objective: This study aimed to determine how increased sleep pressure interferes with postural control according to the availability of attentional resources and visual input.

Methods: Thirteen healthy young adults performed a psychomotor vigilance task and postural tasks after a night of sleep and after 25 h of sleep deprivation. Primary outcome variables were calculated from the center of pressure (CoP) displacement measured by two force plates in various cognitive load and visual state conditions.

Sleep deprivation increases blood pressure in healthy normotensive elderly and attenuates the blood pressure response to orthostatic challenge.

Study Objectives: To determine how aging affects the impact of sleep deprivation on blood pressure at rest and under orthostatic challenge.

Design: Subjects underwent a night of sleep and 24.5 h of sleep deprivation in a crossover counterbalanced design.

Physical activity and obesity: biomechanical and physiological key concepts.

Overweight (OW) and obesity (OB) are often associated with low levels of physical activity. Physical activity is recommended to reduce excess body weight, prevent body weight regain, and decrease the subsequent risks of developing metabolic and orthopedic conditions. However, the impact of OW and OB on motor function and daily living activities must be taken into account.

Postural balance during quiet standing in patients with total hip arthroplasty with large diameter femoral head and surface replacement arthroplasty.

Objective: To compare postural balance between patients who have had either a large diameter head total hip arthroplasty or surface replacement arthroplasty.

Design: Observational study.

Setting: Outpatient biomechanical laboratory.

The John Charnley Award: The functional outcome of hip resurfacing and large-head THA is the same: a randomized, double-blind study.

Unlabelled: Better functional outcome is believed by some to occur after hip resurfacing (HR) than conventional 28-mm total hip arthroplasty (THA) in young and active patients with hip osteoarthritis. However, the postulated superior outcome of HR over THA may simply be the result of a bias in patient selection or the use of a larger femoral head. We therefore asked whether HR would demonstrate superior functional outcome when compared with a THA with a large-diameter femoral head in a randomized, double-blind study.