Jumping : Harrison and others utilization of strain energy during running and….

posted in: Uncategorized | 0

Oat Free treats - Natural Horse treats - For the Horse Horses-store.comJumping : Harrison and others utilization of strain energy during running and….

Indeed, by maintaining a more erect posture than smaller animals, large animals have adapted to minimize the moment generated by the GRF (Biewener, 1990).

Hyperextension of the equine MCP joint appears to be an exception to this rule.

It is likely that the equine pastern has evolved to be sufficiently long to take advantage of the benefit of strain energy storage, but sufficiently short to minimize the risk of tendon, bone and joint injury.

Thus, musculoskeletal loading may not limit merely the speed of gait (Biewener and Taylor, 1986) but also the benefit that can be derived from having long, compliant tendons.

Racehorses are required to exercise regularly at high speeds during training and racing.

Other domesticated horses and wild horses rarely exercise at high speeds with the same frequency.

The prevalence of injury to the MCP joint and the flexor tendons is high in all horses, but it is much greater in racehorses than in wild horses and in horses used for other purposes (eg dressage) (Bailey et al., 1999; Cantley et al., 1999).

The loads induced at these sites due to MCP extension may be manageable at low to moderate speeds and for short bursts at higher speeds, but the extreme loads generated at racing speeds are likely to put these structures at risk for fatigue failure, particularly when the animal is required to run repeatedly at high speeds over relatively long distances.

The mechanism of strain energy utilization may coincide with sports-related injuries in other animals.

The Achilles tendon and the tissues in the arch of the foot contribute significantly to storage and Table2.

Maximum forces calculated in the tendons of the distal forelimb compared to results obtained from invasive experiments reported in the literature Tendon force (N kg–1) Gait Walk Walk Walk Walk Walk Trot Trot Gallop Gallop IM 6.1±1.6 – 8.4±1.5 17 11 11.9±2.1 – 13.2±0.3 – SDFT (SDF+ALSDF) 7.3±2.1 6.73±0.57 5.4±1.0 8 9 14.0±2.5 11.01±0.79 16.7±1.1 9.47±0.74 DDFT (DDF+ALDDF) 5.9±1.7 – 9.3±1.1 9 3 6.2±2.0 – 16.1±6.5 – DDF 3.8±1.1 1.95±0.12 3.8±1.1 – – 4.9±1.3 2.81±0.18 11.3±0.7 4.51±0.31 ALDDF 2.4±0.5 – 7.3±1.5 – – 2.4±0.6 – 5.6±4.6 – Source Present study Butcher et al., 2009 Jansen et al., 1993b Lochner et al., 1980 Platt et al., 1994 Present study Butcher et al., 2009 Present study Butcher et al., 2009 Model and experimental data are compared for walking, trotting and galloping.

Results are presented as means ± 1 s.d. (N=3 for walking and trotting; N=2 for galloping).

All forces are normalized by the mass of the whole animal, including the mass of the rider in galloping.

ALDDF, accessory ligament of the DDF tendon; ALSDF, accessory ligament of the SDF tendon; DDF, deep digital flexor; IM, interosseous muscle; SDF, superficial digital flexor. THE JOURNAL OF EXPERIMENTAL BIOLOGY 4006 S.

M.

Harrison and others utilization of strain energy during running and jumping in humans (Alexander and Bennet-Clark, 1977; Anderson and Pandy, 1993; Fukashiro et al., 1995; Ker et al., 1987), and injuries to the Achilles tendon (Leppilahti and Orava, 1998) and the metatarsal bones (Pester and Smith, 1992) are common in athletes.

Similarly, dogs develop large forces and store significant amounts of strain energy in their Achilles tendons (Alexander and Bennet-Clark, 1977).

Canine Achilles tendons are injured due to overload events (Harasen, 2006), and racing greyhounds injure their hock (analogous to the human ankle) more often than non-racing dogs (Sicard et al., 1999).

Thus, the horse may not be the only animal that benefits from storage and utilization of strain energy at moderate speeds of locomotion, while enduring a greater prevalence of soft-tissue and joint injuries in heavier exercise. Limitations of the analysis was neglected.

Anderson and Pandy compared lower-limb muscle forces obtained from static and dynamic optimization solutions of human gait and showed that muscle activation dynamics has little influence on the solution derived from static optimization (Anderson and Pandy, 2001).

Finally, our model may have underestimated the magnitudes of the contact forces transmitted by the lower limb joints, particularly in the faster gaits such as galloping.

The muscleforce–joint-torque redundancy problem was solved by assuming a minimum muscle activation criterion, which is analogous to minimizing muscle stress (Anderson and Pandy, 2001).

It is likely that this criterion underestimates the amount of muscle cocontraction present during stance, leading to lower estimates of joint contact loading. Comparison with literature data There are a number of limitations related to both the gait experiments performed and the model used to determine musculoskeletal loading and mechanical work done.

The gait experiments were limited in at least four respects.

First, the number of animals used in the experiments was small and, furthermore, the same animals were not used in all of the gait experiments.

Second, because galloping is a non-symmetric gait, the leading and trailing limbs are loaded differently (Merkens et al., 1991).

In particular, studies have shown that the trailing limb experiences larger GRFs than the leading limb (14.8 and 11.6Nkg–1, respectively) (Merkens et al., 1991).

This may explain why the model calculations showed that energy absorption in galloping was less than that in trotting.

Future estimates of the work done during galloping ought to account for differences arising from limb asymmetry.

Third, the speeds of gait employed were slow, and so the results may be different for faster speeds of walking, trotting and galloping.

However, it is likely that the contractile elements perform more work at slower speeds, which makes our estimates of the work done appear conservative (ie the strain energy contributions to total work done may be larger for normal speeds of trotting and galloping).

Also, the comparisons of GRFs, joint torques, joint powers, tendon forces and tendon strains (see Fig.6 and Comparison with literature data) show that the results of this study correlate well with those reported in the literature, albeit with smaller magnitudes in some cases, reflecting the slower speeds tested here.

Fourth, the galloping experiment was not conducted at racing speed, which is typically in the range of 16–18ms–1 (Swanstrom et al., 2005a).

It is likely that musculoskeletal loading and storage and utilization of elastic strain energy are higher than the values indicated by our results when horses gallop at their fastest speeds.

The model calculations were also limited in a number of respects.

First, validation of the model was qualitative because the calculated values of tendon strains were compared against strain gauge results reported in the literature (see below).

Second, the actuator lengths and material properties were obtained from the literature and were not subject-specific.

Future studies should be aimed at using subjectspecific material properties and geometric data to obtain the best possible estimates of muscle forces and muscle–tendon work during gait.

Third, hysteresis was not included in the model used to describe the mechanical behavior of tendon.

Although this effect has not been included in previous biomechanical models of equine locomotion (Meershoek et al., 2001; Swanstrom et al., 2005a), at least 7% of the total strain energy stored in the elastic tissues is estimated to be lost as heat during recoil (Ker, 1981).

Fourth, static optimization was used to solve the muscle-force distribution problem in the distal limb.

The static solution was constrained by the force–length–velocity property of muscle, but activation dynamics Our measurements of joint angles and GRFs and our subsequent calculations of net joint torques are in general agreement with results obtained in previous studies, once differences in gait speeds are taken into account.

The time histories of the joint angular displacements Walk 4 3 2 1 Strain (%) 0 8 6 4 2 0 0 Trot 6 4 2 Strain (%) 0 8 6 4 2 0 0 50 ALDDF 50 SDF 4 2 0 100 0 Stance (%) 2.5 2 1.5 1 0.5 0 8 6 4 2 0 100 0 Stance (%) 50 100 IM ALDDF 6 SDF DDF 2.5 2 1.5 1 0.5 0 IM 50 DDF — 4008 S.

M.

Harrison and others specified whether the limb from which data were collected was the leading limb during galloping.

The trailing limb is loaded to a higher extent than the leading limb during a gallop (Merkens et al., 1991), but how this affects the amount of muscle work performed and the amount of strain energy stored remains unknown.

Fourth, Butcher et al.

Did not consider the load contributed by the ALDDF (Butcher et al., 2009), which we found significantly increases the force transmitted by the distal DDF tendon (Fig.3), thereby increasing the amount of strain energy stored in the distal forelimb.

Finally, Biewener used a different method of determining muscle forces to that adopted in the present study; specifically, Biewener resolved tendon forces only from carpal torques, whereas our muscle force calculations took account of the torques developed by all the joints in the distal limb (Biewener, 1998).

This difference in methodology may explain the different distribution of forces obtained for the tendons of the distal forelimb, especially in relation to the forces calculated for the IM, DDF and SDF tendons.

Other animals use significant amounts of strain energy for locomotion.

As our study was confined to the distal forelimb, it is difficult to directly compare our results with those obtained for the whole animal or even the whole forelimb.

Biewener and Baudinette estimated that as much as 6.4J of strain energy is stored in the long, compliant tendons of the Tamar wallaby during ground contact (Biewener and Baudinette, 1995).

When normalized by body mass, this amounts to 1.36Jkg–1.

We estimate that 0.32±0.08Jkg–1 of strain energy can be stored in each distal forelimb of the horse during slow trotting (Table1).

Because the hind limb may store more elastic energy than the forelimb (Biewener, 1998), a more complete model of the horse is needed to obtain an accurate estimate for the whole animal.

Nonetheless, if we assume that our results can be scaled to the whole body using the results of Biewener (Biewener, 1998) (ie that the forelimbs contribute approximately 30% of the total strain energy), then the total amount of strain energy stored for the horse is approximately 2.0Jkg–1 for all four limbs during a trot.

This result suggests that the horse may utilize more strain energy, when normalized by body mass, than the Tamar wallaby.

Other experiments have shown that up to 60% of the total limb work done by running turkeys is due to the work done by the aponeurotic part of tendon plus that done by the external tendon (Roberts et al., 1997).

Our values for the proportion of work done by the distal tendons in the horse appear high in comparison to that calculated for the running turkey.

However, the values for the entire equine forelimb would be lower, as our analysis excluded the large amount of work done (Dutto et al., 2006) by the muscles of the proximal limb, which have long fibers and short tendons (Payne et al., 2004; Watson and Wilson, 2007). Conclusions ALDDF ALSDF CDE CE CF DDF DE ECR FCR FCU GRF IM LDE LF MC MCP MC3 MR NB PCSA PE P1 P2 P3 SDF Ses UL accessory ligament of the DDF tendon accessory ligament of the SDF tendon common digital extensor contractile element of a Hill-type muscle carpal flexor muscle (FCR, FCU, UL) deep digital flexor digital extensor muscle (CDE, LDE) extensor carpi radialis flexor carpi radialis flexor carpi ulnaris ground reaction force interosseous muscle lateral digital extensor lacertus fibrosis midcarpal joint metacarpophalangeal joint third metacarpal bone magnetic resonance navicular (or distal sesamoid) bone physiological cross-sectional area parallel elastic element of a Hill-type muscle first (or proximal) phalanx second (or middle) phalanx third (or distal) phalanx superficial digital flexor proximal sesamoid bones ulnaris lateralis ACKNOWLEDGEMENTS The authors gratefully acknowledge Nicholas Brown and Tanya Garcia-Nolen for their help with data collection.

We also thank Garry Anderson for his assistance with statistical analysis.

This work was supported by the Rural Industries Research and Development Corporation of the Australian Government, an Australian Research Council Discovery Grant (DP0772838), a VESKI Innovation Fellowship to M.G.P., the Robert and Beverly Lewis Foundation, the Lufkin Foundation and the Grayson-Jockey Club Research Foundation. REFERENCES Ackland, D.

C.

And Pandy, M.

G. (2009).

Lines of action and stabilizing potential of the shoulder musculature.

J.

Anat. 215, 184-197.

Alexander, R.

M. (1974).

The mechanics of jumping by a dog (Canis familiaris).

J.

Zool. (Lond.) 173, 549-573.

Alexander, R.

M. (2002).

Tendon elasticity and muscle function.comp.

Biochem.

Physiol.

A 133, 1001-1011.

Alexander, R.

M.

And Bennet-Clark, H.

C. (1977).

Storage of elastic strain energy in muscle and other tissues.

Nature 265, 114-117.

Alexander, R.

M.

And Vernon, A. (1975).

The mechanics of hopping by kangaroos (Macropodidae).

J.

Zool. (Lond.) 177, 265-303.

Anderson, F.

C.

And Pandy, M.

G. (1993).

Storage and utilization of elastic strain energy during jumping.

J.

Biomech. 26, 1413-1427.

Anderson, F.

C.

And Pandy, M.

G. (2001).

Static and dynamic optimization solutions for gait are practically equivalent.

J.

Biomech. 34, 153-161.

Andriacchi, T.

D.

And Birac, D.

M.

S. (1993).

Functional testing in the anterior cruciate ligament-deficient knee.

Clin.

Orthop.

Relat.

Res. 288, 40-47.

Bailey, C.

J., Reid, S.

W.

J., Hodgson, D.

R.

And Rose, R.

J. (1999).

Impact of injuries and disease on a cohort of two-and three-year-old thoroughbreds in training.

Vet.

Rec. 145, 487-493.

Bennell, K.

L., Malcolm, S.

A., Thomas, S.

A., Wark, J.

D.

And Brukner, P.

D. (1996).

The incidence and distribution of stress fractures in competitive track and field athletes.

Am.

J.

Sport Med. 24, 211-217.

Bergmann, G., Graichen, F.

And Rohlmann, A. (1993).

Hip joint loading during walking and running, measured in two patients.

J.

Biomech. 26, 969-990.

Bergmann, G., Graichen, F.

And Rohlmann, A. (1999).

Hip joint forces in sheep.

J.

Biomech. 32, 769-777.

Bergmann, G., Deuretzbacher, G., Heller, M., Graichen, F., Rohlmann, A., Strauss, J.

And Duda, G.

N. (2001).

Hip contact forces and gait patterns from routine activities.

J.

Biomech. 34, 859-871.

Biewener, A.

A. (1989).

Scaling body support in mammals: limb posture and muscle mechanics.

Science 245, 45-48.

Biewener, A.

A. (1990).

Biomechanics of mammalian terrestrial locomotion.

Science 250, 1097-1103.

Biewener, A.

A. (1998).

Muscle-tendon stresses and elastic energy storage during locomotion in the horse.comp.

Biochem.

Physiol.

B Biochem.

Mol.

Biol. 120, 73-87.

Biewener, A.

And Baudinette, R. (1995).

In vivo muscle force and elastic energy storage during steady-speed hopping of tammar wallabies (Macropus eugenii).

J.

Exp.

Biol. 198, 1829-1841.

Biewener, A.

A.

And Taylor, C.

R. (1986).

Bone strain: a determinant of gait and speed? J.

Exp.

Biol. 123, 383-400.

Bland, J.

M.

And Altman, D.

G. (1996).

Statistics notes: transformations, means, and confidence intervals.

Br.

Med.

J. 312, 1079. The tendons spanning the MCP joint (SDF, DDF and IM) develop the highest forces during walking, trotting and galloping; consequently, this joint is subjected to the highest loads in all three gaits.

SDF, DDF and IM also contribute the majority of the total work done by the distal limb during the stance phase of walking, trotting and galloping.

Thus, the tendons and joints that facilitate storage and utilization of elastic strain energy in the distal forelimb also experience the highest loads, which may explain the high frequency of injuries observed at these sites. LIST OF ABBREVIATIONS AC AL antebrachiocarpal joint accessory ligament THE JOURNAL OF EXPERIMENTAL BIOLOGY Musculoskeletal loading in equine gait Bobbert, M.

F., Alvarez, C.

B.

G., van Weeren, P.

R., Roepstorff, L.

And Weishaupt, M.

A. (2007).

Validation of vertical ground reaction forces on individual limbs calculated from kinematics of horse locomotion.

J.

Exp.

Biol. 210, 1885-1896.

Brama, P.

A.

J., Karssenberg, D., Barneveld, A.

And van Weeren, P.

R. (2001).

Contact areas and pressure distribution on the proximal articular surface of the proximal phalanx under sagittal plane loading.

Equine Vet.

J. 33, 26-32.

Brown, N.

A.

T., Kawcak, C.

E., McIlwraith, C.

W.

And Pandy, M.

G. (2003a).

Architectural properties of distal forelimb muscles in horses, Equus caballus.

J.

Morphol. 258, 106-114.

Brown, N.

A.

T., Pandy, M.

G., Kawcak, C.

E.

And McIlwraith, C.

W. (2003b).

Forceand moment-generating capacities of muscles in the distal forelimb of the horse.

J.

Anat. 203, 101-113.

Buchner, H.

H.

F., Savelberg, H.

H.

C.

M., Schamhardt, H.

C.

And Barneveld, A. (1997).

Inertial properties of Dutch warmblood horses.

J.

Biomech. 30, 653-658.

Butcher, M.

T., Hermanson, J.

W., Ducharme, N.

G., Mitchell, L.

M., Soderholm, L.

V.

And Bertram, J.

E.

A. (2009).

Contractile behavior of the forelimb digital flexors during steady-state locomotion in horses (Equus caballus): an initial test of muscle architectural hypotheses about in vivo function.comp.

Biochem.

Physiol.

A Physiol. 152, 100-114.

Cantley, C.

E., Firth, E.

C., Delahunt, J.

W., Pfeiffer, D.

U.

And Thompson, K.

G. (1999).

Naturally occurring osteoarthritis in the metacarpophalangeal joints of wild horses.

Equine Vet.

J. 31, 73-81.

Cavagna, G.

A., Saibene, F.

P.

And Margaria, R. (1964).

Mechanical work in running.

J.

Appl.

Physiol. 19, 249-256.

Clayton, H.

M., Hodson, E.

And Lanovaz, J.

L. (2000a).

The forelimb in walking horses: 2.net joint moments and joint powers.

Equine Vet.

J. 32, 295-299.

Clayton, H.

M., Schamhardt, H.

C., Willemen, M.

A., Lanovaz, J.

L.

And Colborne, G.

R. (2000b).net joint moments and joint powers in horses with superficial digital flexor tendinitis.

Am.

J.

Vet.

Res. 61, 197-201.

Delp, S.

L., Anderson, F.

C., Arnold, A.

S., Loan, P., Habib, A., John, C.

T., Guendelman, E.

And Thelen, D.

G. (2007).

OpenSim: open-source software to create and analyze dynamic simulations of movement.

IEEE Trans.

Biomed.

Eng. 54, 1940-1950.

Dutto, D.

J., Hoyt, D.

F., Cogger, E.

A.

And Wickler, S.

J. (2004).

Ground reaction forces in horses trotting up an incline and on the level over a range of speeds.

J.

Exp.

Biol. 207, 3507-3514.

Dutto, D.

J., Hoyt, D.

F., Clayton, H.

M., Cogger, E.

A.

And Wickler, S.

J. (2006).

Joint work and power for both the forelimb and hindlimb during trotting in the horse.

J.

Exp.

Biol. 209, 3990-3999.

Fukashiro, S., Komi, P., Järvinen, M.

And Miyashita, M. (1995).

In vivo Achilles tendon loading during jumping in humans.

Eur.

J.

Appl.

Physiol.

Occup.

Physiol. 71, 453-458.

Goodship, A.

E. (1993).

The pathophysiology of flexor tendon injury in the horse.

Equine Vet.

Educ. 5, 23-29.

Harasen, G. (2006).

Ruptures of the common calcaneal tendon.

Can.

Vet.

J. 47, 12191220.

Heglund, N.

C.

M.

A., Fedak Taylor, C.

R.

And Cavagna, G.

A. (1982).

Energetics and mechanics of terrestrial locomotion.

IV.

Total mechanical energy changes as a function of speed and body size in birds and mammals.

J.

Exp.

Biol. 97, 57-66.

Jansen, M., van Buiten, A., van den Bogert, A.

And Schamhardt, H. (1993a).

Strain of the musculus interosseus medius and its rami extensorii in the horse, deduced from in vivo kinematics.

Acta Anat. 147, 118-124.

Jansen, M., van den Bogert, A., Riemersma, D.

And Schamhardt, H. (1993b).

In vivo tendon forces in the forelimb of ponies at the walk, validated by ground reaction force measurements.

Acta Anat. 146, 162-167.

Jansen, M.

O., Schamhardt, H.

C., van den Bogert, A.

J.

And Hartman, W. (1998).

Mechanical properties of the tendinous equine interosseus muscle are affected by in vivo transducer implantation.

J.

Biomech. 31, 485-490.

Ker, R.

F. (1981).

Dynamic tensile properties of the plantaris tendon of sheep (Ovis aries).

J.

Exp.

Biol. 93, 283-302.

Ker, R.

F., Bennett, M.

B., Bibby, S.

R., Kester, R.

C.

And Alexander, R.

M. (1987).

The spring in the arch of the human foot.

Nature 325, 147-149.

Kettelkamp, D.

B.

And Jacobs, A.

W. (1972).

Tibiofemoral contact area-determination and implications.

J.

Bone Joint Surg.

Am. 54, 349-356.

Kim, H.

J., Fernandez, J.

W., Akbarshahi, M., Walter, J.

P., Fregly, B.

J.

And Pandy, M.

G. (2009).

Evaluation of predicted knee-joint muscle forces during gait using an instrumented knee implant.

J.

Orthop.

Res. 27, 1326-1331.

Kostyuk, O., Birch, H.

L., Mudera, V.

And Brown, R.

A. (2004).

Structural changes in loaded equine tendons can be monitored by a novel spectroscopic technique.

J.

Physiol. 554, 791-801.

Leppilahti, J.

And Orava, S. (1998).

Total Achilles tendon rupture: a review.

Sports Med. 25, 79-100.

Lochner, F., Milne, D., Mills, E.

And Groom, J. (1980).

In vivo and in vitro measurement of tendon strain in the horse.

Am.

J.

Vet.

Res. 41, 1929-1937.

McGuigan, M.

P.

And Wilson, A.

M. (2003).

The effect of gait and digital flexor muscle activation on limb compliance in the forelimb of the horse Equus caballus.

J.

Exp.

Biol. 206, 1325-1336.

Meershoek, L.

S., van den Bogert, A.

J.

And Schamhardt, H.

C. (2001).

Model formulation and determination of in vitro parameters of a noninvasive method to calculate flexor tendon forces in the equine forelimb.

Am.

J.

Vet.

Res. 62, 15851593.

Merkens, H.

W., Schamhardt, H.

C., Van Osch, G.

J.

V.

M.

And van den Bogert, A.

J. (1991).

Ground reaction force analysis of Dutch warm blood horse at canter and jumping.

Equine Exerc.

Physiol. 3, 128-135.

Merritt, J.

S., Davies, H.

M.

S., Burvill, C.

And Pandy, M.

G. (2008).

Influence of muscle-tendon wrapping on calculations of joint reaction forces in the equine distal forelimb.

J.

Biomed.

Biotechnol. 2008, 165730. 4009 Merritt, J.

S., Pandy, M.

G., Brown, N.

A.

T., Burvill, C.

R., Kawcak, C.

E., McIlwraith, W.

And Davies, H.

M. (2010).

Mechanical loading of the distal end of the third metacarpal bone in horses during walking and trotting.

Am.

J.

Vet.

Res. 71, 508-514.

Milgrom, C., Giladi, M., Stein, M., Kashtan, H., Margulies, J.

Y., Chisin, R., Steinberg, R.

And Aharonson, Z. (1985).

Stress fractures in military recruits.

A prospective study showing an unusually high incidence.

J.

Bone Joint Surg.

Br. 67B, 732-735.

Minetti, A.

E., ArdigO, L.

P., Reinach, E.

And Saibene, F. (1999).

The relationship between mechanical work and energy expenditure of locomotion in horses.

J.

Exp.

Biol. 202, 2329-2338.

Nunamaker, D.

M., Butterweck, D.

M.

And Black, J. (1991).

In vitro comparison of thoroughbred and standardbred racehorses with regard to local fatigue failure of the third metacarpal bone.

Am.

J.

Vet.

Res. 52, 97-100.

Page, A.

E., Allan, C., Jasty, M., Harrigan, T.

P., Bragdon, C.

R.

And Harris, W.

H. (1993).

Determination of loading parameters in the canine hip in vivo.

J.

Biomech. 26, 571-579.

Pandy, M.

G. (2001).computer modeling and simulation of human movement.

Annu.

Rev.

Biomed.

Eng. 3, 245-273.

Pandy, M.

G.

And Andriacchi, T.

P. (2010).

Muscle and joint function in human locomotion.

Annu.

Rev.

Biomed.

Eng. 12, 401-433.

Pandy, M.

G.

And Zajac, F.

E. (1991).

Optimal muscular coordination strategies for jumping.

J.

Biomech. 24, 1-10.

Parkin, T.

D.

H., Clegg, P.

D., French, N.

P., Proudman, C.

J., Riggs, C.

M., Singer, E.

R., Webbon, P.

M.

And Morgan, K.

L. (2004).

Risk of fatal distal limb fractures among thoroughbreds involved in the five types of racing in the United Kingdom.

Vet.

Rec. 154, 493-497.

Payne, R.

C., Veenman, P.

And Wilson, A.

M. (2004).

The role of the extrinsic thoracic limb muscles in equine locomotion.

J.

Anat. 205, 479-490.

Pennycuick, C.

J. (1975).

On the running of the gnu (Connochaetes taurinus) and other animals.

J.

Exp.

Biol. 63, 775-799.

Pester, S.

And Smith, P.

C. (1992).

Stress fractures in the lower extremities of soldiers in basic training.

Orthop.

Rev. 21, 297-303.

Platt, D., Wilson, A.

M., Timbs, A., Wright, I.

M.

And Goodship, A.

E. (1994).

Novel force transducer for the measurement of tendon force in vivo.

J.

Biomech. 27, 14891493.

Reinbolt, J.

A., Schutte, J.

F., Fregly, B.

J., Koh, B.

I., Haftka, R.

T., George, A.

D.

And Mitchell, K.

H. (2005).

Determination of patient-specific multi-joint kinematic models through two-level optimization.

J.

Biomech. 32, 621-626.

Riemersma, D., van den Bogert, A., Jansen, M.

And Schamhardt, H. (1996).

Tendon strain in the forelimbs as a function of gait and ground characteristics and in vitro limb loading in ponies.

Equine Vet.

J. 28, 133-138.

Roberts, T.

J., Marsh, R.

L., Weyand, P.

G.

And Taylor, C.

R. (1997).

Muscular force in running turkeys: the economy of minimizing work.

Science 275, 1113-1115.

Roland, E.

S., Hull, M.

L.

And Stover, S.

M. (2005).

Design and demonstration of a dynamometric horseshoe for measuring ground reaction loads of horses during racing conditions.

J.

Biomech. 38, 2102-2112.

Schamhardt, H.

C., Merkens, H.

W.

And Van Osch, G.

J.

V.

M. (1991).

Ground reaction force analysis of horses ridden at the walk and trot.

Equine Exerc.

Physiol. 3, 120-127.

Shelburne, K.

B., Pandy, M.

G., Anderson, F.

C.

And Torry, M.

R. (2004).

Pattern of anterior cruciate ligament force in normal walking.

J.

Biomech. 37, 797-805.

Shelburne, K.

B., Torry, M.

R.

And Pandy, M.

G. (2006).

Contributions of muscles, ligaments, and the ground-reaction force to tibiofemoral joint loading during normal gait.

J.

Orthop.

Res. 24, 1983-1990.

Sicard, G.

K., Short, K.

And Manley, P.

A. (1999).

A survey of injuries at five greyhound racing tracks.

J.

Small Anim.

Pract. 40, 428-432.

Swanstrom, M.

D., Stover, S.

M., Hubbard, M.

And Hawkins, D.

A. (2004).

Determination of passive mechanical properties of the superficial and deep digital flexor muscle-ligament-tendon complexes in the forelimbs of horses.

Am.

J.

Vet.

Res. 65, 188-197.

Swanstrom, M.

D., Zarucco, L., Hubbard, M., Stover, S.

M.

And Hawkins, D.

A. (2005a).

Musculoskeletal modeling and dynamic simulation of the thoroughbred equine forelimb during stance phase of the gallop.

J.

Biomech.

Eng. 127, 318-328.

Swanstrom, M.

D., Zarucco, L., Stover, S.

M., Hubbard, M., Hawkins, D.

A., Driessen, B.

And Steffey, E.

P. (2005b).

Passive and active mechanical properties of the superficial and deep digital flexor muscles in the forelimbs of anesthetized Thoroughbred horses.

J.

Biomech. 38, 579-586.

Taylor, C.

R., Schmidt-Nielsen, K.

And Raab, J.

L. (1970).

Scaling of energetic cost of running to body size in mammals.

Am.

J.

Physiol. 219, 1104-1107.

Van Soest, A.

J., Schwab, A.

L., Bobbert, M.

F.

And van Ingen Schenau, G.

J. (1993).

The influence of the biarticularity of the gastrocnemius muscle on verticaljumping achievement.

J.

Biomech. 26, 1-8.

Watson, J.

C.

And Wilson, A.

M. (2007).

Muscle architecture of biceps brachii, triceps brachii and supraspinatus in the horse.

J.

Anat. 210, 32-40.

Weller, R. (2006).

The influence of conformation on locomotor biomechanics and its effect on performance in the horse, PhD Thesis 2006, The Royal Veterinary College, University of London.

Wilson, A.

M., McGuigan, M.

P., Su, A.

And van den Bogert, A.

J. (2001).

Horses damp the spring in their step.

Nature 414, 895-899.

Witte, T.

H., Knill, K.

And Wilson, A.

M. (2004).

Determination of peak vertical ground reaction force from duty factor in the horse (Equus caballus).

J.

Exp.

Biol. 207, 36393648.

Zajac, F.

E. (1989).

Muscle and tendon: properties, models, scaling, and application to biomechanics and motor control.

Crit.

Rev.

Biomed.

Eng. 17, 359-411.

Zajac, F.

E. (1993).

Muscle coordination of movement: a perspective.

J.

Biomech. 26, 109-124. THE JOURNAL OF EXPERIMENTAL BIOLOGY

Read more about Jumping : Harrison and others utilization of strain energy during running and….:

Equestrian Products – Guardian Horse Bedding, Equiderma Skin Products, Equilinn Sports Bra

Other Sources:

  • Cali Girl Horse Adventure Game – Play Horse Riding and Decorating …
  • Horse (zodiac) – Wikipedia, the free encyclopedia
  • Bridles – Beval Saddlery Ltd
  • Equestrian Products – Guardian Horse Bedding, Equiderma Skin Products, Equilinn Sports Bra, Learn more about Oat Free treats – Natural Horse treats – For the Horse Horses-store.com HERE:

    Horses-Store.com and Jumping : Harrison and others utilization of strain energy during running and….
    Horses-Store.com - Jumping : Harrison and others utilization of strain energy during running and….
    Horses-Store.com and Jumping : Harrison and others utilization of strain energy during running and….
    Horses-Store.com - Jumping : Harrison and others utilization of strain energy during running and….