The Dunkin Hartley Guinea Pig Is a Model of Primary Osteoarthritis That Also Exhibits Early Onset Myofiber Remodeling That Resembles Human Musculoskeletal Aging.

Skeletal muscle dysfunction, articular cartilage degeneration, and bone loss occur essentially in parallel during aging. Mechanisms contributing to this systemic musculoskeletal decline remain incompletely understood, limiting progress toward developing effective therapeutics. Because the progression of human musculoskeletal aging is slow, researchers rely on rodent models to identify mechanisms and test interventions.

Gait and electromyographic alterations due to early onset of injury and eventual rupture of the cranial cruciate ligament in dogs: A pilot study.

Objective: Identify relevant electromyography (EMG), kinematic, and kinetic changes resulting from monopolar radiofrequency energy (MRFE)-induced cranial cruciate ligament (CCL) injury and eventual rupture in dogs.

Study Design: Experimental, repeated measures.

Animals: Five purpose-bred female dogs free of orthopedic and neurologic disease.

Effect of Rear Wheel Suspension on Tilt-in-Space Wheelchair Shock and Vibration Attenuation.

Background: Suspension systems are designed to reduce shock and vibration exposure. An aftermarket rear-wheel suspension system is now available for manual tilt-in-space wheelchairs.

Objective: To compare quantifiable shock and vibration on a rigid manual tilt-in-space wheelchair to published data on manual wheelchairs and to determine whether aftermarket rear suspension system will significantly decrease shock exposure when traversing common obstacles.

Longitudinal Assessment of Bone Mineral Density and Body Composition in Competitive Cyclists.

Baker, BS and Reiser II, RF. A longitudinal assessment of bone mineral density and body composition in competitive cyclists. J Strength Cond Res 31(11): 2969-2976, 2017-Competitive cycling has been associated with low bone mineral density (BMD); however, BMD is a multifaceted issue.

Biomechanical and histologic evaluation of the effects of underwater treadmill exercise on horses with experimentally induced osteoarthritis of the middle carpal joint.

OBJECTIVE To evaluate the effects of exercise in an underwater treadmill (UWT) on forelimb biomechanics and articular histologic outcomes in horses with experimentally induced osteoarthritis of the middle carpal joint. ANIMALS 16 horses. PROCEDURES An osteochondral fragment was induced arthroscopically (day 0) in 1 middle carpal joint of each horse.

Postural Steadiness and Ankle Force Variability in Peripheral Neuropathy.

Introduction: The purpose was to determine the effect of peripheral neuropathy (PN) on motor output variability for ankle muscles of older adults, and the relation between ankle motor variability and postural stability in PN patients.

Methods: Older adults with (O-PN) and without PN (O), and young adults (Y) underwent assessment of standing postural stability and ankle muscle force steadiness.

Results: O-PN displayed impaired ankle muscle force control and postural stability compared with O and Y groups.

Relationships between lower-extremity flexibility, asymmetries, and the Y balance test.

Joint flexibility, bilateral asymmetries in flexibility, and bilateral asymmetries in performance of the Y Balance Test have been associated with injuries. However, relationships among these attributes are unclear. The goal of this investigation was to examine how flexibility and flexibility asymmetries relate to the Y Balance Test.

Use of an inertial measurement unit to assess the effect of forelimb lameness on three-dimensional hoof orientation in horses at a walk and trot.

Objective: To determine intralimb orientation changes with an inertial measurement unit (IMU) in hooves of horses at a walk and trot after induction of weight-bearing single forelimb lameness and to determine whether hoof orientations are similar to baseline values following perineural anesthesia.

Animals: 6 clinically normal horses.

Procedures: 3-D hoof orientations were determined with an IMU mounted on the right forelimb hoof during baseline conditions, during 3 grades of lameness (induced by application of pressure to the sole), and after perineural anesthesia.

The role of muscle activation in cruciate disease.

Traditional investigations into the etiopathogenesis of canine cranial cruciate ligament (CCL) disease have focused primarily on the biological and mechanical insults to the CCL as a passive stabilizing structure of the stifle. However, with recent collaboration between veterinarians and physical therapists, an increased focus on the role of muscle activity and aberrant motor control mechanisms associated with anterior cruciate ligament (ACL) injuries and rehabilitation in people has been transferred and applied to dogs with CCL disease. Motor control mechanisms in both intact and cruciate-deficient human knees may have direct translation to canine patients, because the sensory and motor components are similar, despite moderate anatomic and biomechanical differences.

Effect of forelimb lameness on hoof kinematics of horses at a walk.

Objective: To determine kinematic changes to the hoof of horses at a walk after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness (baseline) values after perineural anesthesia.

Animals: 6 clinically normal Quarter Horses.

Procedures: For each horse, a sole-pressure model was used to induce 3 grades of lameness in the right forelimb, after which perineural anesthesia was administered to eliminate lameness.

Effect of forelimb lameness on hoof kinematics of horses at a trot.

Objective: To determine kinematic changes to the hoof of horses at a trot after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness values after perineural anesthesia.

Animals: 6 clinically normal Quarter Horses.

Procedures: For each horse, a sole-pressure model was used to induce 3 grades (grades 1, 2, and 3) of lameness in the right forelimb, after which perineural anesthesia was administered to alleviate lameness.

Kinematic and kinetic analysis of dogs during trotting after amputation of a pelvic limb.

Objective: To evaluate biomechanical gait adaptations in dogs after amputation of a pelvic limb.

Animals: Client-owned dogs (12 pelvic limb-amputee and 24 quadruped [control] dogs).

Procedures: Dogs were trotted across 3 in-series force platforms.

Kinematic and kinetic analysis of dogs during trotting after amputation of a thoracic limb.

Objective: To characterize biomechanical differences in gait between dogs with and without an amputated thoracic limb.

Animals: Client-owned dogs (16 thoracic-limb amputee and 24 quadruped [control] dogs).

Procedures: Dogs were trotted across 3 in-series force platforms.

Evaluation of aerodynamic and rolling resistances in mountain-bike field conditions.

Aerodynamic and rolling resistances are the two major resistances that affect road cyclists on level ground. Because of reduced speeds and markedly different tyre-ground interactions, rolling resistance could be more influential in mountain biking than road cycling. The aims of this study were to quantify 1) aerodynamic resistance of mountain-bike cyclists in the seated position and 2) rolling resistances of two types of mountain-bike tyre (smooth and knobby) in three field surfaces (road, sand and grass) with two pressure inflations (200 and 400 kPa).

Obesity does not impair walking economy across a range of speeds and grades.

Despite the popularity of walking as a form of physical activity for obese individuals, relatively little is known about how obesity affects the metabolic rate, economy, and underlying mechanical energetics of walking across a range of speeds and grades. The purpose of this study was to quantify metabolic rate, stride kinematics, and external mechanical work during level and gradient walking in obese and nonobese adults. Thirty-two obese [18 women, mass = 102.

Relationships between asymmetries in functional movements and the star excursion balance test.

Lower-extremity functional asymmetries (LEFAs) have been shown to be related to performance and injury risk. However, consistency of expression between tasks is not well understood. The goal of this investigation was to examine relationships in vertical ground reaction force LEFA during standing, bodyweight squats, countermovement jumps (CMJs), and single-leg drop landings along with those produced in the Star Excursion Balance Test (SEBT).

Validation of an equine inertial measurement unit system in clinically normal horses during walking and trotting.

Objective: To validate an equine inertial measurement unit (IMU) system rigidly attached to a hoof against a 3-D optical kinematics system in horses during walking and trotting.

Animals: 5 clinically normal horses.

Procedures: 5 swing phases of the hooves of the right forelimb and hind limb were collected via both 3-D optical and IMU systems from 5 horses during walking and trotting.

Aging-related cocontraction effects during ankle strategy balance recovery following tether release in women.

Increased antagonistic muscle activation during balance recovery has been documented during proprioceptive reliant responses in older adults. The authors examined ankle muscle cocontraction levels in young and older adults during balance recovery from a tether-release-induced, vestibular-input-reliant perturbation. Nine healthy young adult and 9 older women without history of falls performed maximum isometric plantar flexion and dorsiflexion trials followed by balance recovery trials using the ankle strategy.

Effects of fatigue on bilateral ground reaction force asymmetries during the squat exercise.

Physical performance and injury risk have been related to functional asymmetries of the lower extremity. The effect of fatigue on asymmetries is not well understood. The goal of this investigation was to examine asymmetries during fatiguing repetitions and sets of the free-weight barbell back squat exercise.

Energetics and biomechanics of inclined treadmill walking in obese adults.

Unlabelled: Brisk walking is a recommended form of exercise for obese individuals. However, lower-extremity joint loads and the associated risk of musculoskeletal injury or pathological disease increase with walking speed. Walking uphill at a slower speed is an alternative form of moderate intensity exercise that may reduce joint loading.

The effect of floor slope on sub-maximal lifting capacity and technique.

Inclined surfaces, where both the lifter and load are on the slope, may be encountered in a jobsite situation. The purpose of this study was to determine if facing up or down a sloped surface (10 degrees and 20 degrees ) would affect maximal acceptable weights of lift (MAWL) using a 10 min psychophysical approach with symmetric freestyle technique at 4 lifts/min. Seventeen healthy men and 18 women determined floor to knuckle height MAWL while facing uphill, downhill, and on a level surface.

Gender and bilateral differences in single-leg countermovement jump performance with comparison to a double-leg jump.

Expectations may be for both legs to function identically during single- and double-leg vertical jumps. However, several reasons might prevent this from occurring. The goals of this investigation were twofold: assess the presence of side-to-side jump height differences during single-leg jumps in a homogenous group of healthy subjects and determine if those with a jump height asymmetry possessed consistent biomechanical differences during single-and double-leg jumps.

Peak lifting velocities of men and women for the reduced inertia squat exercise using force control.

The purpose of the research was to determine peak velocities for the reduced inertia squat exercise at various resistance levels based on an isometric strength assessment for both men and women. On a Smith machine modified for pneumatic resistance, 12 males and 12 females previously trained college-age participants performed a maximal isometric strength assessment with knee angles of 90 degrees , 110 degrees , 130 degrees , 150 degrees and 170 degrees (180 degrees = full extension) followed by dynamic maximal effort squats with resistance maintained at 40, 50, 60, 70, and 80% of their lowest maximum isometric strength. No interaction existed between the men and women during isometric strength tests with the men stronger in every joint position (P < 0.

High resistance/low repetition vs. low resistance/high repetition training: effects on performance of trained cyclists.

In order to investigate the effects of a resistance training modality on cycling performance, 23 trained club-level cyclists were placed into high resistance/low repetition (H-Res), low resistance/high repetition (H-Rep), or cycling-only groups for a 10-week program. All 3 groups followed the same cycling plan, but the H-Res and H-Rep groups added resistance training. Testing pre and post consisted of a graded incremental lactate profile test on an ergometer, with blood lactate being sampled.