{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,2]],"date-time":"2025-11-02T16:18:58Z","timestamp":1762100338831},"reference-count":29,"publisher":"The Company of Biologists","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2005,3,15]]},"abstract":"<jats:title>SUMMARY<\/jats:title><jats:p>Different locomotor tasks, such as moving up or down grades or changing speed, require that muscles adjust the amount of work they perform to raise or lower, accelerate or decelerate the animal's center of mass. During level trotting in the horse, the triceps had shortening strains of around 10.6%while the vastus shortened 8.1% during the stance phase. Because of the 250%increase in metabolic rate in horses trotting up a 10% incline which is,presumably, a result of the increased requirement for mechanical work, we hypothesized that muscle strain during trotting would be increased in both the triceps and the vastus over that observed when trotting on the level. Because times of contact are similar in level and incline trotting, we also hypothesized that strain rates of these muscles would be increased,accompanied by an increase in EMG activity. We examined the lateral head of the triceps and the vastus lateralis while trotting up a 10% incline(5.7\u00b0) over a range of speeds. The triceps shortened by 18% compared with 10.6% shortening on the level, and the vastus shortened by 18.5% compared with 8.1% on the level. The increased shortening velocities that were observed in both muscles probably reduced the force that any given set of activated muscle fibers could produce. If this pattern held for other limb muscles that do work to elevate the horse's center of mass on an incline, then a greater volume of muscle would have to be recruited to generate an equivalent force for body support. This was reflected in significant increases in the EMG intensity(IEMG) of both muscles.<\/jats:p>","DOI":"10.1242\/jeb.01485","type":"journal-article","created":{"date-parts":[[2005,3,14]],"date-time":"2005-03-14T18:19:16Z","timestamp":1110824356000},"page":"1191-1200","source":"Crossref","is-referenced-by-count":30,"title":["<i>In vivo<\/i>muscle function<i>vs<\/i>speed II. Muscle function trotting up an incline"],"prefix":"10.1242","volume":"208","author":[{"given":"Steven J.","family":"Wickler","sequence":"first","affiliation":[{"name":"Equine Research Center, California State Polytechnic University, Pomona,CA 91768-4032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Donald F.","family":"Hoyt","sequence":"additional","affiliation":[{"name":"Biological Sciences Department, California State Polytechnic University,Pomona, CA 91768-4032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrew A.","family":"Biewener","sequence":"additional","affiliation":[{"name":"Concord Field Station, Department of Organismic and Evolutionary Biology,Harvard University, Bedford, MA 01730, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Edward A.","family":"Cogger","sequence":"additional","affiliation":[{"name":"Equine Research Center, California State Polytechnic University, Pomona,CA 91768-4032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kristin L.","family":"De La Paz","sequence":"additional","affiliation":[{"name":"Equine Research Center, California State Polytechnic University, Pomona,CA 91768-4032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"237","reference":[{"key":"2021042505375295000_REF1","doi-asserted-by":"crossref","unstructured":"Alexander, R. M., Maloiy, G. M. O., Hunter, B., Jayes, A. S. and Nturibi, J. (1979). Mechanical stresses in fast locomotion of buffalo (Syncerus caffer) and elephant (Loxodonta africana). J. Zool.189,135-144.","DOI":"10.1111\/j.1469-7998.1979.tb03956.x"},{"key":"2021042505375295000_REF2","doi-asserted-by":"crossref","unstructured":"Back, W., van den Bogert, A. J., van Weeren, P. R., Bruin, G. and Barneveld, A. (1993). Quantification of the locomotion of Dutch Warmblood foals. Acta Anat.146,141-147.","DOI":"10.1159\/000147436"},{"key":"2021042505375295000_REF3","doi-asserted-by":"crossref","unstructured":"Biewener, A. A. (1998). Muscle function in vivo: a comparison of muscles used for elastic energy savings versus muscles used to generate mechanical power. Amer. Zool.78,703-717.","DOI":"10.1093\/icb\/38.4.703"},{"key":"2021042505375295000_REF4","unstructured":"Biewener, A. A. (2003). Animal Locomotion. Oxford: Oxford University Press."},{"key":"2021042505375295000_REF5","doi-asserted-by":"crossref","unstructured":"Biewener, A. A., Konieczynski, D. D. and Baudinette, R. V.(1998). In vivo muscle force-length behavior during steady-speed hopping in tammar wallabies. J. Exp. Biol.201,1681-1694.","DOI":"10.1242\/jeb.201.11.1681"},{"key":"2021042505375295000_REF6","unstructured":"Biewener, A. A., McGowan, C., Card, G. M. and Baudinette, R. V. (2004). Dynamics of leg muscle function in tammar wallabies (M. eugenii) during level versus incline hopping. J. Exp. Biol.207,211-223."},{"key":"2021042505375295000_REF7","doi-asserted-by":"crossref","unstructured":"Carrier, D. R. (1996). Function of the intercostal muscles in trotting dogs: ventilation or locomotion? J. Exp. Biol.199,1455-1465.","DOI":"10.1242\/jeb.199.7.1455"},{"key":"2021042505375295000_REF8","doi-asserted-by":"crossref","unstructured":"Carrier, D. R., Gregersen C. S. and Silverton, N. A.(1998). Dynamic gearing in running dogs. J. Exp. Biol.201,3185-3195.","DOI":"10.1242\/jeb.201.23.3185"},{"key":"2021042505375295000_REF9","doi-asserted-by":"crossref","unstructured":"Daley, M. A. and Biewener, A. A. (2003). Muscle force-length dynamics during level versus incline locomotion: a comparison of in vivo performance of two guinea fowl ankle extensors. J. Exp. Biol.206,2941-2958.","DOI":"10.1242\/jeb.00503"},{"key":"2021042505375295000_REF10","doi-asserted-by":"crossref","unstructured":"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.","DOI":"10.1242\/jeb.01171"},{"key":"2021042505375295000_REF11","doi-asserted-by":"crossref","unstructured":"Eaton, M. D., Evans, D. L., Hodgson, D. R. and Rose, R. J.(1995). Effect of treadmill incline and speed on metabolic rate during exercise in thoroughbred horses. J. Appl. Physiol.79,951-957.","DOI":"10.1152\/jappl.1995.79.3.951"},{"key":"2021042505375295000_REF12","doi-asserted-by":"crossref","unstructured":"English, A. W. (1984). An electromyographic analysis of compartments of cat lateral gastrocnemius muscle during unrestrained locomotion. J. Neurophysiol.52,114-125.","DOI":"10.1152\/jn.1984.52.1.114"},{"key":"2021042505375295000_REF13","doi-asserted-by":"crossref","unstructured":"Gillis, G. B. and Biewener, A. A. (2001). Hindlimb muscle function in relation to speed and gait: In vivo patterns of strain and activation in a hip and knee extensor of the rat (Rattus norvegicus). J. Exp. Biol.204,2717-2731.","DOI":"10.1242\/jeb.204.15.2717"},{"key":"2021042505375295000_REF14","doi-asserted-by":"crossref","unstructured":"Gillis, G. B. and Biewener, A. A. (2002). Effects of surface grade on proximal hindlimb muscle strain and activation during rat locomotion. J. Appl. Physiol.93,1731-1743.","DOI":"10.1152\/japplphysiol.00489.2002"},{"key":"2021042505375295000_REF15","doi-asserted-by":"crossref","unstructured":"Hoyt, D. F. and Taylor, C. R. (1981). Gait and the energetics of locomotion in horses. Nature292,239-240.","DOI":"10.1038\/292239a0"},{"key":"2021042505375295000_REF16","unstructured":"Hoyt, D. F., Wickler, S. J., Biewener, A. A., Cogger, E. A. and De La Paz, K. L. (2005). In vivo muscle function vs speed: I. Muscle strain in relation to length change of the muscle-tendon unit. J. Exp. Biol.208,1175-1190."},{"key":"2021042505375295000_REF17","doi-asserted-by":"crossref","unstructured":"Hoyt, D. F., Wickler, S. J. and Cogger, E. A.(2000). Time of contact and step length: the effect of limb length, running speed, load carrying and incline. J. Exp. Biol.203,221-227.","DOI":"10.1242\/jeb.203.2.221"},{"key":"2021042505375295000_REF18","doi-asserted-by":"crossref","unstructured":"Kaya, M., Leonard, T. and Herzog, W. (2003). Coordination of medial gastrocnemius and soleus force during cat locomotion. J. Exp. Biol.206,3645-3655.","DOI":"10.1242\/jeb.00544"},{"key":"2021042505375295000_REF19","doi-asserted-by":"crossref","unstructured":"Kram, R. and Taylor, C. R. (1990). Energetics of running: a new perspective. Nature346,265-267.","DOI":"10.1038\/346265a0"},{"key":"2021042505375295000_REF20","doi-asserted-by":"crossref","unstructured":"Marsh, R. L., Ellerby, D. J., Carr, J. A., Henry, H. T. and Buchanan, C. I. (2004). Partitioning the energetics of walking and running: Swinging the limbs is expensive. Science303,80-83.","DOI":"10.1126\/science.1090704"},{"key":"2021042505375295000_REF21","doi-asserted-by":"crossref","unstructured":"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.","DOI":"10.1242\/jeb.00254"},{"key":"2021042505375295000_REF22","doi-asserted-by":"crossref","unstructured":"Robert, C., Valette, J. P. and Denoix, J. M.(2000). The effects of treadmill inclination and speed on the activity of two hindlimb muscles in the trotting horse. Equine vet. J.32,312-317.","DOI":"10.2746\/042516400777032246"},{"key":"2021042505375295000_REF23","doi-asserted-by":"crossref","unstructured":"Roberts, T. J., Marsh, R. L., Weyand, P. G. and Taylor, C. R. (1997). Muscular force in running turkeys: The economy of minimizing work. Science275,1113-1114.","DOI":"10.1126\/science.275.5303.1113"},{"key":"2021042505375295000_REF24","doi-asserted-by":"crossref","unstructured":"Roy, R. R., Hutchison, D. L., Pierotti, D. J., Hodgson, D. R. and Edgerton, V. R. (1991). EMG patterns of rat ankle extensors and flexors during treadmill locomotion and swimming. J. Appl. Physiol.70,2522-2529.","DOI":"10.1152\/jappl.1991.70.6.2522"},{"key":"2021042505375295000_REF25","doi-asserted-by":"crossref","unstructured":"Scholle, H. C., Schumann, N. P., Biedermann, F., Stegeman, D. F., Grassme, R., Roeleveld, K., Schilling, N. and Fischer, M. S.(2001). Spatiotemporal surface EMG characteristics from rat triceps brachii muscle during treadmill locomotion indicate selective recruitment of functionally distinct duscle regions. Exp. Brain Res.138,26-36.","DOI":"10.1007\/s002210100685"},{"key":"2021042505375295000_REF26","unstructured":"Taylor, C. R. (1994). Relating mechanics and energetics during exercise. Adv. Vet. Sci. Comp. Med.38A,181-214."},{"key":"2021042505375295000_REF27","doi-asserted-by":"crossref","unstructured":"Wickler, S. J., Hoyt, D. F., Cogger, E. A. and Hirschbein, M. H. (2000). Preferred speed and cost of transport: The effect of incline. J. Exp. Biol.203,2195-2200.","DOI":"10.1242\/jeb.203.14.2195"},{"key":"2021042505375295000_REF28","doi-asserted-by":"crossref","unstructured":"Wickler, S. J., Hoyt, D. F., Cogger, E. A. and McGuire, R.(2002). The cost of transport in an extended trot. Equine Excer. Physiol.6, 126-130.","DOI":"10.1111\/j.2042-3306.2002.tb05404.x"},{"key":"2021042505375295000_REF29","doi-asserted-by":"crossref","unstructured":"Wickler, S. J., Hoyt, D. F., Cogger, E. A. and Myers, G.(2003). The energetics of the trot-gallop transition. J. Exp. Biol.206,1557-1564.","DOI":"10.1242\/jeb.00276"}],"container-title":["Journal of Experimental Biology"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/journals.biologists.com\/jeb\/article-pdf\/208\/6\/1191\/1255219\/1191.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"http:\/\/journals.biologists.com\/jeb\/article-pdf\/208\/6\/1191\/1255219\/1191.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,1,24]],"date-time":"2024-01-24T02:04:47Z","timestamp":1706061887000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.biologists.com\/jeb\/article\/208\/6\/1191\/9440\/In-vivo-muscle-function-vs-speed-II-Muscle"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2005,3,15]]},"references-count":29,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2005,3,15]]}},"URL":"https:\/\/doi.org\/10.1242\/jeb.01485","relation":{},"ISSN":["1477-9145","0022-0949"],"issn-type":[{"value":"1477-9145","type":"electronic"},{"value":"0022-0949","type":"print"}],"subject":[],"published":{"date-parts":[[2005,3,15]]}}}