The effect of horseshoes and surfaces on horse and jockey centre of mass displacements at gallop

Horseshoes influence how horses’ hooves interact with different ground surfaces, during the impact, loading and push-off phases of a stride cycle. Consequently, they impact on the biomechanics of horses’ proximal limb segments and upper body. By implication, different shoe and surface combinations could drive changes in the magnitude and stability of movement patterns in horse-jockey dyads. This study aimed to quantify centre of mass (COM) displacements in horse-jockey dyads galloping on turf and artificial tracks in four shoeing conditions: 1) aluminium; 2) barefoot; 3) GluShu; and 4) steel. Thirteen retired racehorses and two jockeys at the British Racing School were recruited for this intervention study. Tri-axial acceleration data were collected close to the COM for the horse (girth) and jockey (kidney-belt), using iPhones (Apple Inc.) equipped with an iOS app (SensorLog, sample rate = 50 Hz). Shoe-surface combinations were tested in a randomized order and horse-jockey pairings remained constant. Tri-axial acceleration data from gallop runs were filtered using bandpass Butterworth filters with cut-off frequencies of 15 Hz and 1 Hz, then integrated for displacement using Matlab. Peak displacement was assessed in both directions (positive ‘maxima’, negative ‘minima’) along the cranio-caudal (CC, positive = forwards), medio-lateral (ML, positive = right) and dorso-ventral (DV, positive = up) axes for all strides with frequency ≥2 Hz (mean = 2.06 Hz). Linear mixed-models determined whether surfaces, shoes or shoe-surface interactions (fixed factors) significantly affected the displacement patterns observed, with day, run and horse-jockey pairs included as random factors; significance was set at p<0.05. Data indicated that surface-type significantly affected peak COM displacements in all directions for the horse (p<0.0005) and for all directions (p≤0.008) but forwards in the jockey. The largest differences were observed in the DV-axis, with an additional 5.7 mm and 2.5 mm of downwards displacement for the horse and jockey, respectively, on the artificial surface. Shoeing condition significantly affected all displacement parameters except ML-axis minima for the horse (p≤0.007), and all displacement parameters for the jockey (p<0.0005). Absolute differences were again largest vertically, with notable similarities amongst displacements from barefoot and aluminium trials compared to GluShu and steel. Shoe-surface interactions affected all but CC-axis minima for the jockey (p≤0.002), but only the ML-axis minima and maxima and DV-axis maxima for the horse (p≤0.008). The results support the idea that hoof-surface interface interventions can significantly affect horse and jockey upper-body displacements. Greater sink of hooves on impact, combined with increased push-off during the propulsive phase, could explain the higher vertical displacements on the artificial track. Variations in distal limb mass associated with shoe-type may drive compensatory COM displacements to minimize the energetic cost of movement. The artificial surface and steel shoes provoked the least CC-axis movement of the jockey, so may promote greatest stability. However, differences between horse and jockey mean displacements indicated DV-axis and CC-axis offsets with compensatory increases and decreases, suggesting the dyad might operate within displacement limits to maintain stability. Further work is needed to relate COM displacements to hoof kinematics and to determine whether there is an optimum configuration of COM displacement to optimise performance and minimise injury.

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Low-velocity impacts into granular material: application to small-body landing

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab624 ◽

2021 ◽

Vol 503 (3) ◽

pp. 3460-3471

Author(s):

Naomi Murdoch ◽

Melanie Drilleau ◽

Cecily Sunday ◽

Florian Thuillet ◽

Arnaud Wilhelm ◽

...

Keyword(s):

Granular Material ◽

Small Body ◽

Surface Interactions ◽

Resistance Force ◽

Hydrodynamic Drag ◽

Reduced Gravity ◽

Low Velocity ◽

Low Gravity ◽

Terrestrial Gravity ◽

The Impact

ABSTRACT With the flourishing number of small body missions that involve surface interactions, understanding the mechanics of spacecraft – surface interactions is crucial for improving our knowledge about the landing phases of space missions, for preparing spacecraft operations, and for interpreting the results of measurements made during the surface interactions. Given their regolith-covered surfaces, the process of landing on a small body can be considered as an impact at low-velocity on to a granular material in reduced-gravity. In order to study the influence of the surface material, projectile shape, and gravity on the collision dynamics, we used two experimental configurations (one for terrestrial gravity experiments and one for reduced-gravity experiments) to perform low-velocity collisions into different types of granular materials: quartz sand, and two different sizes of glass beads (1.5 and 5 mm diameter). Both a spherical and a cubic projectile (with varying impact orientation) were used. The experimental data support a drag model for the impact dynamics composed of both a hydrodynamic drag force and quasi-static resistance force. The hydrodynamic and quasi-static contributions are related to the material frictional properties, the projectile geometry, and the gravity. The transition from a quasi-static to a hydrodynamical regime is shown to occur at lower impact velocities in reduced-gravity trials than in terrestrial gravity trials, indicating that regolith has a more fluid-like behaviour in low-gravity. The reduced quasi-static regime of a granular material under low-gravity conditions leads to a reduction in the strength, resulting in a decreased resistance to penetration and larger penetration depths.

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Magnetic Resonance-Compatible Arm-Crank Ergometry: A New Platform Linking Whole-Body Calorimetry to Upper-Extremity Biomechanics and Arm Muscle Metabolism

10.21203/rs.3.rs-37885/v1 ◽

2020 ◽

Author(s):

Riemer JK Vegter ◽

Sebastiaan van den Brink ◽

Leonora J Mouton ◽

Anita Sibeijn-Kuiper ◽

Lucas H.V. van der Woude ◽

...

Keyword(s):

Magnetic Resonance ◽

Surface Electromyography ◽

Motor Units ◽

Daily Practice ◽

Muscle Disease ◽

Upper Body ◽

Whole Body ◽

Energetic Efficiency ◽

The Impact

Abstract Background: Evaluation of the effect of human upper body training regimens may benefit from knowledge of local energy expenditure in arm muscles. To that end, we developed a novel asynchronous arm-crank ergometry platform for use in a clinical magnetic resonance (MR) scanner with 31P spectroscopy capability to study arm muscle energetics. The utility of the platform was tested in an investigation of the impact of daily practice on the energetic efficiency of execution of an arm-cranking task (ACT) in healthy subjects. Results: We recorded the first ever in vivo 31P MR spectra from the human biceps bracii muscle during ACT execution pre- and post-three weeks of daily practice bouts, respectively. Complementary datasets on whole body oxygen consumption, arm muscle electrical activity, arm-force and power output, respectively, were obtained in the mock-up scanner. The mean gross mechanical efficiency of execution of the ACT significantly increased 1.5-fold from 5.7 ± 1.2% to 8.6 ± 1.7% (P<0.05) after training, respectively. However, in only one subject this improvement was associated with recruitment of strictly oxidative motor units in the working biceps muscle. In all other subjects, biceps pH fell below 6.8 during exercise indicating recruitment of anaerobic motor units, the magnitude of which was either unaffected (two subjects) or even increased (two subjects) post-training. Surface electromyography and mechanical force recordings revealed that individuals employed various arm muscle recruitment strategies, using either predominantly elbow flexor muscles (two subjects), elbow extensor muscles (one subject,) or a combination of the two (two subjects), respectively. Three weeks of training improved muscle coordination but did not alter individual strategies. Conclusions: The new platform has produced the first ever in vivo dynamic data on human biceps energy and pH balance during upper body exercise. It allows evaluation of cyclic motor performance and outcomes of upper-body training regimens in healthy novices by integrating these new measurements with whole body calorimetry, surface electromyography and biomechanical measurements. This methodology may be equally valid for lower-limb impaired athletes, wheelchair users and patients with debilitating muscle disease.

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Effect of acute antagonist static stretching on upper-body agonist power

International Journal of Sports Science & Coaching ◽

10.1177/1747954119884441 ◽

2019 ◽

Vol 15 (1) ◽

pp. 53-59

Author(s):

Dave Elliott ◽

Dayne Massey

Keyword(s):

Repeated Measures ◽

Effective Means ◽

Upper Body ◽

Static Stretching ◽

Repeated Measures Design ◽

Significant Difference ◽

Potential Benefits ◽

Upper Body Power ◽

The Impact ◽

Practical Implications

There are many studies showing acute static stretching to be detrimental to power generation. However, the majority have focused upon the impact of stretching the agonist musculature. To date, few have examined the potential benefits of acute antagonist static stretching; none have focused on upper-body power. Utilising a repeated-measures design, 30 male participants were randomly assigned to one of two groups whereupon they performed four bench-throw tests; two control (NO-STRETCH) and two experimental (STRETCH), in a counter-balanced manner. Prior to the experimental measures, participants undertook a series of static antagonist stretches. Mean Pmax (SD) in the NO-STRETCH trials was 862.76 (146)W and 898.50 (144)W, respectively. For STRETCH trial 1, Pmax = 930.10 (146)W and trial 2, Pmax = 953.36 (136)W. When compared to the respective NO-STRETCH trials, antagonist static stretching did have a significant effect on Pmax for both the initial ( P < 0.01, d = 1.33) and the re-stretching procedures ( P < 0.01, d = 1.35). A significant difference was also found between the STRETCH trials ( P < 0.01, d = 0.46). The results have practical implications for those involved in upper-body power activities. Specifically, incorporating upper-body antagonist static stretching into pre-performance routines might offer a simple and effective means of enhancing agonist power.

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THE IMPACT OF 3 MONTHS OF SUPERVISED EXERCISE ON CHANGE IN FUNCTION: COMPARISONS BY ARTHRITIS STATUS

Innovation in Aging ◽

10.1093/geroni/igz038.136 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

pp. S34-S35

Author(s):

Lauren M Abbate ◽

Katherine Hall ◽

Megan Pearson ◽

Richard Sloane ◽

Kelli D Allen ◽

...

Keyword(s):

Physical Function ◽

Upper Body ◽

Lower Body ◽

Time Points ◽

Supervised Exercise ◽

Mean Differences ◽

The Impact ◽

Usual Gait Speed ◽

Minute Walk

Abstract Physical activity is an established intervention for the management of arthritis. This study evaluated the effect of 3 months of participation in Gerofit on physical function by arthritis status. Participants, 519 Veterans aged ≥ 65 years self-reported either no arthritis (NA) (49%), upper body arthritis (UB) (8.2%), lower body arthritis (LB) (12.7%), or both upper and lower body arthritis (UB&LB) (30.4%) upon enrollment. Physical function measures [10-meter usual gait speed (m/s) (GS), arm curls (AC), chair stands (CS), and 6-minute walk (yards) (SMW)] were assessed at baseline and follow-up. Mean differences between time points were calculated. At baseline, compared to NA, LB and UB&LB had slower GS (1.10 and 1.06 vs 1.13) and shorter SMW distance (468.8 and 448.8 vs 490.7). All groups tended to increase physical function, with greatest improvement among LB (GS=0.27, AC=2.06, CS=2.52, SMW=42.53). Participation in Gerofit is associated with functional gains, regardless of burden of disease.

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The Effect of Handcycle Ergometer Exercise on Glucose Tolerance in Ambulatory and Non-Ambulatory Adolescents

Pediatric Exercise Science ◽

10.1123/pes.2016-0047 ◽

2017 ◽

Vol 29 (1) ◽

pp. 63-72 ◽

Cited By ~ 1

Author(s):

Kevin R. Short ◽

April M. Teague ◽

Jake C. Klein ◽

Elizabeth Malm-Buatsi ◽

Dominic Frimberger

Keyword(s):

Insulin Sensitivity ◽

Glucose Tolerance ◽

Upper Body ◽

Whole Body ◽

Control Group ◽

Mobility Limitations ◽

Upper Body Exercise ◽

Significant Group ◽

Ergometer Exercise ◽

The Impact

Purpose:Whole body or leg exercise before a meal can increase insulin sensitivity, but it is unclear whether the same can occur with upper body exercise since a smaller muscle mass is activated. We measured the impact of a single session of handcycle exercise on glucose tolerance and insulin sensitivity.Methods:Nonambulatory (Non-Amb) adolescents with spina bifida or cerebral palsy (4F/3M), or ambulatory peers (Control, 4F/7M) completed 2 glucose tolerance tests on separate days, preceded by either rest or a 35-min bout of moderate-to-vigorous intermittent handcycle exercise.Results:The Non-Amb group had higher body fat (mean ± SD: 38 ± 12%, Control: 24 ± 9, p = .041) but similar VO2peak (17.7 ± 6.1 ml/kg/min, Control: 21.1 ± 7.9). Fasting glucose and insulin were normal for all participants. Compared with the rest trial, exercise resulted in a reduction in glucose area under the curve (11%, p = .008) without a significant group x trial interaction and no difference in the magnitude of change between groups. Insulin sensitivity was increased 16% (p = .028) by exercise in the Control group but was not significantly changed in the Non-Amb group.Conclusion:A single bout of handcycle exercise improves glucose tolerance in adolescents with and without mobility limitations and could therefore help maintain or improve metabolic health.

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Kinematic Analysis of a Five-Legged Mobile Robot

Volume 2: 34th Annual Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2010-28993 ◽

2010 ◽

Cited By ~ 1

Author(s):

Muhammed R. Pac ◽

Dan O. Popa

Keyword(s):

Kinematic Analysis ◽

Degrees Of Freedom ◽

Parallel Robot ◽

Parallel Robots ◽

The Body ◽

Legged Robots ◽

Upper Body ◽

Design Changes ◽

Robot Performance ◽

The Impact

Legged robots are more maneuverable, and can negotiate rough terrain much better than conventional locomotion using wheels. However, since the kinematic or dynamic analysis of such robots involves closed chains, it is typically more difficult to investigate the impact of design changes, such as the number, or the design of its legs, to robot performance. Most legged robots consist of 4 legs (quadrupeds) or 6 legs (hexapods). This paper discusses the kinematic analysis of an unconventional, symmetrical 5-legged robot with 2-DOF (Degrees Of Freedom) universal joints in each leg. The analysis was carried out in order to predict the mobility of the upper body platform, and investigate the number of robot actuators needed for mobility. The product of exponentials formulation with respect to the local coordinate frames is used to describe the twists of the joints. The analysis is based on the idea that the robot body platform along with the legs can be considered instantaneously as a parallel robot manipulating the ground. Hence, the analysis can be done using the Jacobian formulation of parallel robots. Simulation results confirm the mobility analysis that the robot can have at most 3-DOF for the body and that these freedoms are coupled rotations and translations in 3D space also with a dependence on the configuration of the robot.

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Carbohydrates Alone or Mixing With Beef or Whey Protein Promote Similar Training Outcomes in Resistance Training Males: A Double-Blind, Randomized Controlled Clinical Trial

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2017-0003 ◽

2017 ◽

Vol 27 (5) ◽

pp. 408-420 ◽

Cited By ~ 9

Author(s):

Fernando Naclerio ◽

Marcos Seijo ◽

Eneko Larumbe-Zabala ◽

Conrad P. Earnest

Keyword(s):

Resistance Training ◽

Whey Protein ◽

Performance Outcomes ◽

Fat Free Mass ◽

Upper Body ◽

Controlled Clinical Trial ◽

Post Intervention ◽

Double Blind ◽

Resistance Training Program ◽

The Impact

Beef powder is a new high-quality protein source scarcely researched relative to exercise performance. The present study examined the impact of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on strength performance (1RM), body composition (via plethysmography), limb circumferences and muscular thickness (via ultrasonography), following an 8-week resistance-training program. After being randomly assigned to one of the following groups: Beef, Whey, or Carbohydrate, twenty four recreationally physically active males (n = 8 per treatment) ingested 20 g of supplement, mixed with orange juice, once a day (immediately after workout or before breakfast). Post intervention changes were examined as percent change and 95% CIs. Beef (2.0%, CI, 0.2–2.38%) and Whey (1.4%, CI, 0.2–2.6%) but not Carbohydrate (0.0%, CI, -1.2–1.2%) increased fat-free mass. All groups increased vastus medialis thickness: Beef (11.1%, CI, 6.3–15.9%), Whey (12.1%, CI, 4.0, -20.2%), Carbohydrate (6.3%, CI, 1.9–10.6%). Beef (11.2%, CI, 5.9–16.5%) and Carbohydrate (4.5%, CI, 1.6–7.4%), but not Whey (1.1%, CI, -1.7–4.0%), increased biceps brachialis thickness, while only Beef increased arm (4.8%, CI, 2.3–7.3%) and thigh (11.2%, 95%CI 0.4–5.9%) circumferences. Although the three groups significantly improved 1RM Squat (Beef 21.6%, CI 5.5–37.7%; Whey 14.6%, CI, 5.9–23.3%; Carbohydrate 19.6%, CI, 2.2–37.1%), for the 1RM bench press the improvements were significant for Beef (15.8% CI 7.0–24.7%) and Whey (5.8%, CI, 1.7–9.8%) but not for carbohydrate (11.4%, CI, -0.9-23.6%). Protein-carbohydrate supplementation supports fat-free mass accretion and lower body hypertrophy. Hydrolyzed beef promotes upper body hypertrophy along with similar performance outcomes as observed when supplementing with whey isolate or maltodextrin.

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Yoga to Reduce Leisure Constraints for Residents of Assisted Living Facilities

10.21926/obm.geriatr.2004135 ◽

2020 ◽

Vol 4 (4) ◽

Author(s):

Em V. Adams ◽

Marieke Van Puymbroeck ◽

Brandi M. Crowe ◽

Cynthia L. S. Pury ◽

Arlene A. Schmid ◽

...

Keyword(s):

Assisted Living ◽

Past Research ◽

Community Dwelling ◽

Pain Interference ◽

Upper Body ◽

Assisted Living Facilities ◽

Functional Fitness ◽

Leisure Constraints ◽

Yoga Intervention ◽

The Impact

Residents of assisted living facilities face leisure constraints (barriers to leisure activities) at higher rates than their community-dwelling peers. Past research suggests yoga may be an effective intervention to decrease leisure constraints to physical activity. Therefore, the purpose of this study was to evaluate the impact of an eight-week yoga intervention on the leisure constraints of residents of assisted living facilities. The study employed a convergent mixed methods design to assess the impact of a 50-minute group yoga intervention, offered twice a week for eight weeks by a Certified Yoga Therapist. The intervention was implemented at four different assisted living facilities in the Southeastern United States. Pre- and post-quantitative measures were collected to assess overall leisure constraints, limitations in functional fitness, and pain interference. Qualitative data were collected via focus groups post-yoga intervention to determine participants’ perspectives on changes in leisure constraints. A total of 15 participants completed the study. Data analysis revealed significant improvements in two of the four functional fitness measures: upper body endurance (measured by the Arm Curl Test), and trunk stability (measured by the Function in Sitting Test). No significant improvements were observed in pain interference, or overall leisure constraints. Qualitative results indicated participants used yoga to help engage in daily activities such as housework, sleeping, and walking. Additionally, participants reported using yoga to help manage pain. In this sample, yoga appears to be a promising intervention to help reduce specific leisure constraints such as a reduction in functional fitness. Additionally, yoga shows some promise as a pain management strategy, warranting further research.

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Local Dynamic Stability of Self-Paced Treadmill Walking Versus Fixed-Speed Treadmill Walking

Journal of Biomechanical Engineering ◽

10.1115/1.4045595 ◽

2020 ◽

Vol 142 (4) ◽

Author(s):

Yuyang Qian ◽

Kaiming Yang ◽

Yu Zhu ◽

Wei Wang ◽

Chenhui Wan

Keyword(s):

Dynamic Stability ◽

Control Strategies ◽

Three Dimensional ◽

Treadmill Walking ◽

Upper Body ◽

Local Dynamic ◽

Gait Stability ◽

Treadmill Speed ◽

Local Dynamic Stability ◽

The Impact

Abstract The purpose of this study was to assess the influence of gait stability induced by treadmill accelerations during self-paced treadmill walking (SPW). Local dynamic stability of three-dimensional (3D) upper body accelerations and hip angles were quantified. The results demonstrated that SPW was more unstable and had higher risk of falling than fixed-speed treadmill walking (FSW) under the impact of treadmill accelerations. The frequency domain analysis of treadmill speed indicated that intrastride treadmill speed variation was the dominating cause of the instability, and self-paced control strategies which can reduce the intrastride variation may achieve higher gait stability during SPW.

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