Publications by authors named "Matthew Ruder"

This cross-sectional study aimed to identify and validate cut-points for measuring physical activity using Axivity AX6 accelerometers positioned at the shank in older adults. Free-living physical activity was assessed in 35 adults aged 55 and older, where each participant wore a shank-mounted Axivity and a waist-mounted ActiGraph simultaneously for 72 hours. Optimized cut-points for each participant's Axivity data were determined using an optimization algorithm to align with ActiGraph results.

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Background: The growth in participation in collegiate athletics has been accompanied by increased sport-related injuries. The complex and multifactorial nature of sports injuries highlights the importance of monitoring athletes prospectively using a novel and integrated biopsychosocial approach, as opposed to contemporary practices that silo these facets of health.

Methods: Data collected over two competitive basketball seasons were used in a principal component analysis (PCA) model with the following objectives: (i) investigate whether biomechanical PCs (i.

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Wearable sensors may allow research to move outside of controlled laboratory settings to be able to collect real-world data in clinical populations, such as older adults with osteoarthritis. However, the reliability of these sensors must be established across multiple out-of-lab data collections. Nine older adults with symptomatic knee arthritis wore wearable inertial sensors on their proximal tibias during an outdoor 6-minute walk test outside of a controlled laboratory setting as part of a pilot study.

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Background: Lower limb biomechanics, including asymmetry, are frequently monitored to determine sport performance level and injury risk. However, contributing factors extend beyond biomechanical and asymmetry measures to include psychological, sociological, and environmental factors. Unfortunately, inadequate research has been conducted using holistic biopsychosocial models to characterize sport performance and injury risk.

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Jump-based asymmetry is often used as an indicator of sport performance and may be used to discern injury susceptibility. Due to task specificity, however, countermovement jump asymmetry may not be representative of on-court asymmetry. As such, we assessed the association between countermovement jump asymmetry and on-court impact asymmetry metrics (n=3, and n=4, respectively) using linear regressions (α=0.

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To compare the inter-session placement reliability for researcher-placed and self-placed sensors, and to evaluate the validity and reliability of waveforms and discrete variables from researcher-placed and self-placed sensors following a previously described alignment correction algorithm. Fourteen healthy, pain-free participants underwent gait analysis over two data collection sessions. Participants self-placed an inertial sensor on their left tibia and a researcher placed one on their right tibia, before completing 10 overground walking trials.

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Article Synopsis
  • The study analyzes the effectiveness of rotator cuff repair, noting that a significant percentage of procedures fail, often despite appearing intact on imaging.
  • It aims to measure both static retraction and maximum dynamic elongation of repaired tendons post-surgery in nine patients.
  • Results show a mean static retraction of 10.0 mm after three months and a maximum dynamic elongation of 1.4 mm during movement, indicating that tendon elongation occurs under both static and dynamic conditions.
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Background: Rotator cuff repair provides pain relief for many patients; however, retears are relatively common and affect approximately 20%-70% of patients after repair. Although magnetic resonance imaging (MRI) offers the ability to assess tissue characteristics such as tear size, retraction, and fatty infiltration, it provides little insight into the quality of the musculotendinous tissues the surgeon will encounter during surgery. However, shear wave elastography (SWE) could provide an indirect assessment of quality (ie, stiffness) by measuring the speed of shear waves propagating through tissue.

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Repair tissue healing after rotator cuff repair remains a significant clinical problem, and excessive shoulder activity after surgical repair is believed to contribute to re-tears. In contrast, small animal studies have demonstrated that complete removal of activity impairs tendon healing and have advocated for an "appropriate" level of activity, but in humans the appropriate amount of shoulder activity to enhance healing is not known. As an initial step toward understanding the relationship between postoperative shoulder activity and repair tissue healing, the objectives of this study were to assess the precision, accuracy, and feasibility of a wrist-worn triaxial accelerometer for measuring shoulder activity.

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Background: Approximately 20-60% of rotator cuff repairs fail with higher failure rates in patients with larger or more chronic tears. Although MRI provides an objective estimate of tear size, it can only provide qualitative descriptions of tear chronicity. By contrast, ultrasound shear wave elastography (SWE) may assess tear chronicity by estimating tissue mechanical properties (ie, shear modulus).

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The rotator cuff is theorized to contribute to force couples required to produce glenohumeral kinematics. Impairment in these force couples would theoretically result in impaired ball-and-socket kinematics. Although less frequently used than traditional kinematic descriptors (e.

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Unlabelled: The degree to which standard laboratory gait assessments accurately reflect impact loading in an outdoor running environment is currently unknown.

Purpose: To compare tibial shock between treadmill and road marathon conditions.

Methods: One hundred ninety-two runners (men/women, 105/87; age, 44.

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Purpose: Foot strike patterns (FSP) influence landing mechanics, with rearfoot strike (RFS) runners exhibiting higher impact loading than forefoot strike (FFS) runners. The few studies that included midfoot strike (MFS) runners have typically grouped them together with FFS. In addition, most running studies have been conducted in laboratories.

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Background: As barefoot (BF) running provides important sensory information that influence landing patterns, it may also affect loading symmetry.

Research Question: The purpose of this investigation was to examine whether symmetry of loading in a group of injured runners would be improved in a novice, barefoot condition.

Methods: Cross-sectional design evaluating 67 injured RFS runners.

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