Kinematics and kinetics of dogs completing jump and A-frame exercises

2021 ◽  
pp. 1-16
Author(s):  
S. Blake ◽  
R. Ferro de Godoy

Many police dogs do not reach their expected retirement age as they are no longer able to cope with the physical demands of the job. Annual licensing requires police dogs to complete a series of agility tasks, including jumping and negotiating an A-frame obstacle, both of which are associated with higher injury rates in canine agility competitors. This study sought to measure conformational, kinematic, and kinetic parameters of actively employed police German Shepherd Dogs (GSDs), whilst completing a 55 cm jump hurdle, and a standard A-frame. Each dog completed three repetitions of each obstacle and was also recorded at both walk and trot. Contact pressures and forces were measured, whilst joint kinematics were recorded using reflective markers and a high-speed camera. Results found that static hip angle was significantly correlated with hip flexion at trot, during jump suspension and at the apex of the A-frame. Stifle and hock flexion were greatest during the suspension phase of jump (56.98±11.710° and 54.51±17.430°). Shoulder and elbow flexion were greatest at the apex of A-frame (104.34±16.744° and 75.72±20.804°), whilst carpal extension was highest upon landing from the jump (125.77±7.071°). Peak vertical force (PFz) when normalised for body mass (BM) increased when landing from A-frame (14.28 N/kg BM) as opposed to landing from the jump obstacle (12.055 N/kg·BM). Our results show that increased range of motion (ROM) is required during both jumping and negotiation of A-frame compared to walk and trot, but more significantly, greater forces are incurred upon landing from the A-frame than compared to jumping. It was also observed that dogs were subject to high degrees of torsion in the distal limbs upon landing from the A-frame due to trained behaviours. We conclude that use of agility equipment generates greater forces through the musculoskeletal system and requires a greater ROM than what is experienced at walk and trot, which may contribute to early retirement ages in police dogs.

2016 ◽  
Vol 31 (4) ◽  
pp. 211-217 ◽  
Author(s):  
Danielle N Jarvis ◽  
Kornelia Kulig

In dance, high demands are placed on the lower extremity joints during jumping tasks. The purpose of this study was to compare biomechanical demands placed on the lower extremity joints during the takeoff and landing phases of saut de chat leaps. METHODS: Thirty healthy, experienced dancers with 20.8±4.9 yrs of dance training performed 5 saut de chat leaps. A three-dimensional motion analysis system and force plates were used to collect kinematic and kinetic data. Ground reaction force (GRF) peaks and impulse and sagittal plane kinematics and kinetics of the hip, knee, ankle, and metatarsophalangeal (MTP) joints were calculated for the takeoff and landing phases of each leap. RESULTS: Saut de chat takeoffs demonstrated greater braking GRF impulse (p<0.001), while landings demonstrated greater peak vertical GRF (p<0.001). During takeoff, greater kinetic demands were placed on the MTP (p<0.001) and ankle (p<0.001) joints, while during landing greater kinetic demands were placed on the hip (p=0.037) joint. CONCLUSIONS: Both the takeoff and landing phases of saut de chat leaps place significant demands on a dancer’s body. Takeoff involves greater demands on the more distal joints and requires more braking forces, while the landing phase involves greater demands on the more proximal joints of the lower extremity and requires the dancer to absorb more vertical force. These demands, combined with extensive repetition of movements during training, may contribute to the high number of chronic injuries seen in dance.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 874
Author(s):  
Heli K. Hyytiäinen ◽  
Laura Blomvall ◽  
Mikko Hautala ◽  
Anu K. Lappalainen

Information on the biomechanics of police dogs’ tasks is important in understanding their work-related injuries and dysfunctions. This study aimed to develop and test a measurement tool for dogs’ functional bite force and to report modified long attack-related kinetic and kinematic values. Twenty Finnish male police dogs, 7 German Shepherd Dogs (GSDs) and 13 Belgian Shepherd Dogs, Malinois (BSDMs), were included. Dogs accelerated 25 m and bit the helper’s sleeve, fitted with three force sensors. Dogs were wearing a 3D accelerometer and were videotaped with a high-speed camera. The sleeve’s reliability for measuring the dog’s bite force was evaluated via intraclass correlation and Cronbach’s alpha. Otherwise, a Mann–Whitney U-test was used, with significance set at p = 0.05. The sleeve’s test-retest reliability was moderate to good (intraclass correlation of 0.75), and internal consistency was high (Cronbach’s alpha 0.75). The GSDs’ median bite force was 360.4 N (interquartile range (IQR) 628.6 N) and BSDMs’ 247.0 N (IQR 289.8 N). Median acceleration maximum was 7.1 gravitational force equivalent (g) and median deceleration maximum was 11.6 g, with highest recorded forces being 9.2 g and 13.1 g, respectively. The measurement sleeve was a reliable tool for measuring functional bite force in GSDs and BSDMs. Forces related to bite, approach and impact in the two breeds were reported.


1996 ◽  
Vol 12 (2) ◽  
pp. 207-224 ◽  
Author(s):  
Glenn S. Fleisig ◽  
Rafael F. Escamilla ◽  
James R. Andrews ◽  
Tomoyuki Matsuo ◽  
Yvonne Satterwhite ◽  
...  

Kinematic and kinetic aspects of baseball pitching and football passing were compared. Twenty-six high school and collegiate pitchers and 26 high school and collegiate quarterbacks were analyzed using three-dimensional high-speed motion analysis. Although maximum shoulder external rotation occurred earlier for quarterbacks, maximum angular velocity of pelvis rotation, upper torso rotation, elbow extension, and shoulder internal rotation occurred earlier and achieved greater magnitude for pitchers. Quarterbacks had shorter strides and stood more erect at ball release. During arm cocking, quarterbacks demonstrated greater elbow flexion and shoulder horizontal adduction. To decelerate the arm, pitchers generated greater compressive force at the elbow and greater compressive force and adduction torque at the shoulder. These results may help explain differences in performance and injury rates between the two sports.


2009 ◽  
Vol 8 (3) ◽  
pp. 245-254 ◽  
Author(s):  
Simon N. Pearson ◽  
John B. Cronin ◽  
Patria A. Hume ◽  
David Slyfield

2014 ◽  
Vol 809-810 ◽  
pp. 907-911
Author(s):  
Jun Long Wang ◽  
Jie Hou ◽  
Ting Jiang ◽  
Yong Jun He ◽  
Yao Dong Liang

Dry waters with an average diameter of 82 μm were prepared by a high speed mixed route. The formaldehyde absorption kinetics of dry waters was investigated by simulating indoor formaldehyde pollution in glass chamber. The results showed that pseudo-second order model could be used to simulate the adsorption process; the adsorption rate was highest in the initial 60 minutes; when the adsorption lasted for 180 minutes, the adsorption reached equilibrium.


1987 ◽  
Vol 3 (1) ◽  
pp. 47-62 ◽  
Author(s):  
Ross H. Sanders ◽  
Barry D. Wilson

This study investigated the in-flight rotation of elite 3m springboard divers by determining the angular momentum requirement about the transverse axis through the divers center of gravity (somersault axis) required to perform a forward 1 1/2 somersault with and without twist. Three elite male divers competing in the 1982 Commonwealth Games were filmed using high-speed cinematography while performing the forward 1 1/2 somersault in the pike position and the forward 1 1/2 somersault with one twist in a free position. The film was digitized to provide a kinematic description of each dive. An inclined axis technique appeared to be the predominant means of producing twist after takeoff from the board. The angular momentum about the somersault axis after takeoff was greater for the forward 1 1/2 somersault with twist than the forward 1 1/2 somersault without twist for all three divers. The difference in angular momentum between the two dives of each diver ranged from 6% to 19%. The most observable difference between the dives during the preflight phases was the degree of hip flexion at takeoff. There was more hip flexion at takeoff in 5132D than 103B for all three divers. This difference ranged from 9° to 18° (mean = 14°).


2008 ◽  
Vol 105 (4) ◽  
pp. 1262-1273 ◽  
Author(s):  
Andrew M. Carroll ◽  
David V. Lee ◽  
Andrew A. Biewener

We investigate how the biarticular long head and monoarticular lateral head of the triceps brachii function in goats ( Capra hircus) during jumping and landing. Elbow moment and work were measured from high-speed video and ground reaction force (GRF) recordings. Muscle activation and strain were measured via electromyography and sonomicrometry, and muscle stress was estimated from elbow moment and by partitioning stress based on its relative strain rate. Elbow joint and muscle function were compared among three types of limb usage: jump take-off (lead limb), the step prior to jump take-off (lag limb), and landing. We predicted that the strain and work patterns in the monoarticular lateral head would follow the kinematics and work of the elbow more closely than would those of the biarticular long head. In general this prediction was supported. For instance, the lateral head stretched (5 ± 2%; mean ± SE) in the lead and lag limbs to absorb work during elbow flexion and joint work absorption, while the long head shortened (−7 ± 1%) to produce work. During elbow extension, both muscles shortened by similar amounts (−10 ± 2% long; −13 ± 4% lateral) in the lead limb to produce work. Both triceps heads functioned similarly in landing, stretching (13 ± 3% in the long head and 19 ± 5% in the lateral) to absorb energy. In general, the long head functioned to produce power at the shoulder and elbow, while the lateral head functioned to resist elbow flexion and absorb work, demonstrating that functional diversification can arise between mono- and biarticular muscle agonists operating at the same joint.


2021 ◽  
Vol 2039 (1) ◽  
pp. 012027
Author(s):  
S A Perminov ◽  
E V Lipnyagov ◽  
M A Parshakova

Abstract The effect of a low-boiling impurity (CO2 gas <1.5% mol) on the kinetics of boiling-up of superheated n-pentane in a vertical glass tube have been studied by high-speed video (2050 fps). The method of continuous pressure decrease from 2.00 to 0.10 MPa (in the temperature range of 100.2-145.1 °C), as well as the method of measuring the lifetimes of superheated liquids at 0.10 MPa (90.2-134.1 °C) have been used. The inner surface of the tube has two visible defects, one of which defines the boundary of the attainable superheat. After degassing the system, the defects of tube cease to play an appreciable role, the active centers are redistributed. The temperature of the attainable superheat increases from the initial value by 20 °C in tests with gas and by 10 °C in subsequent tests without it. The result obtained may be related to physical gas adsorption on the glass surface during the process of evacuation of the system.


2014 ◽  
Vol 47 (1) ◽  
pp. 113-118 ◽  
Author(s):  
H. M. Clayton ◽  
N. C. Stubbs ◽  
M. Lavagnino

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