{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T10:34:39Z","timestamp":1789468479085,"version":"build-2803163510"},"reference-count":76,"publisher":"Wiley","issue":"24","license":[{"start":{"date-parts":[[2017,11,19]],"date-time":"2017-11-19T00:00:00Z","timestamp":1511049600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"DOI":"10.13039\/100000069","name":"National Institute of Arthritis and Musculoskeletal and Skin Diseases","doi-asserted-by":"publisher","award":["R01 AR\u2010052345"],"award-info":[{"award-number":["R01 AR\u2010052345"]}],"id":[{"id":"10.13039\/100000069","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000069","name":"National Institute of Arthritis and Musculoskeletal and Skin Diseases","doi-asserted-by":"publisher","award":["R01 AR\u2010050520"],"award-info":[{"award-number":["R01 AR\u2010050520"]}],"id":[{"id":"10.13039\/100000069","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["The Journal of Physiology"],"published-print":{"date-parts":[[2017,12,15]]},"abstract":"<jats:sec><jats:title>Key points<\/jats:title><jats:p><jats:list list-type=\"bullet\">\n<jats:list-item><jats:p>In tonic, isometric, plantarflexion contractions, physiological tremor increases as the ankle joint becomes plantarflexed.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>Modulation of physiological tremor as a function of muscle stretch differs from that of the stretch reflex amplitude.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>Amplitude of physiological tremor may be altered as a function of reflex pathway gains.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>Healthy humans likely increase their \u03b3\u2010static fusimotor drive when muscles shorten.<\/jats:p><\/jats:list-item>\n<jats:list-item><jats:p>Quantification of physiological tremor by manipulation of joint angle may be a useful experimental probe of afferent gains and\/or the integrity of automatic fusimotor control.<\/jats:p><\/jats:list-item>\n<\/jats:list><\/jats:p><\/jats:sec><jats:sec><jats:title>Abstract<\/jats:title><jats:p>The involuntary force fluctuations associated with physiological (as distinct from pathological) tremor are an unavoidable component of human motor control. While the origins of physiological tremor are known to depend on muscle afferentation, it is possible that the mechanical properties of muscle\u2013tendon systems also affect its generation, amplification and maintenance. In this paper, we investigated the dependence of physiological tremor on muscle length in healthy individuals. We measured physiological tremor during tonic, isometric plantarflexion torque at 30% of maximum at three ankle angles. The amplitude of physiological tremor increased as calf muscles shortened in contrast to the stretch reflex whose amplitude decreases as muscle shortens. We used a published closed\u2010loop simulation model of afferented muscle to explore the mechanisms responsible for this behaviour. We demonstrate that changing muscle lengths does not suffice to explain our experimental findings. Rather, the model consistently required the modulation of \u00a0\u03b3\u2010static fusimotor drive to produce increases in physiological tremor with muscle shortening \u2013 while successfully replicating the concomitant reduction in stretch reflex amplitude. This need to control \u03b3\u2010static fusimotor drive explicitly as a function of muscle length has important implications. First, it permits the amplitudes of physiological tremor and stretch reflex to be decoupled. Second, it postulates neuromechanical interactions that require length\u2010dependent \u03b3 drive modulation to be independent from \u03b1 drive to the parent muscle. Lastly, it suggests that physiological tremor can be used as a simple, non\u2010invasive measure of the afferent mechanisms underlying healthy motor function, and their disruption in neurological conditions.<\/jats:p><\/jats:sec>","DOI":"10.1113\/jp274899","type":"journal-article","created":{"date-parts":[[2017,10,12]],"date-time":"2017-10-12T01:52:45Z","timestamp":1507773165000},"page":"7331-7346","source":"Crossref","is-referenced-by-count":21,"title":["Physiological tremor increases when skeletal muscle is shortened: implications for fusimotor control"],"prefix":"10.1113","volume":"595","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1545-158X","authenticated-orcid":false,"given":"Kian","family":"Jalaleddini","sequence":"first","affiliation":[{"name":"Division of Biokinesiology and Physical Therapy University of Southern California  Los Angeles CA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akira","family":"Nagamori","sequence":"additional","affiliation":[{"name":"Division of Biokinesiology and Physical Therapy University of Southern California  Los Angeles CA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher M.","family":"Laine","sequence":"additional","affiliation":[{"name":"Division of Biokinesiology and Physical Therapy University of Southern California  Los Angeles CA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mahsa A.","family":"Golkar","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering McGill University  Montr\u00e9al QC Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert E.","family":"Kearney","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering McGill University  Montr\u00e9al QC Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francisco J.","family":"Valero\u2010Cuevas","sequence":"additional","affiliation":[{"name":"Division of Biokinesiology and Physical Therapy University of Southern California  Los Angeles CA USA"},{"name":"Department of Biomedical Engineering University of Southern California  Los Angeles CA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2017,11,19]]},"reference":[{"key":"e_1_2_5_2_1","doi-asserted-by":"publisher","DOI":"10.1186\/1743-0003-5-18"},{"key":"e_1_2_5_3_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10439-009-9852-5"},{"key":"e_1_2_5_4_1","doi-asserted-by":"publisher","DOI":"10.1152\/jn.00832.2002"},{"key":"e_1_2_5_5_1","doi-asserted-by":"publisher","DOI":"10.1152\/jn.2001.85.2.869"},{"key":"e_1_2_5_6_1","doi-asserted-by":"publisher","DOI":"10.1023\/A:1005585030764"},{"key":"e_1_2_5_7_1","doi-asserted-by":"publisher","DOI":"10.1023\/A:1005687416896"},{"key":"e_1_2_5_8_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF00124244"},{"key":"e_1_2_5_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/0006-8993(77)90013-0"},{"key":"e_1_2_5_10_1","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.06-05-01308.1986"},{"key":"e_1_2_5_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0165-0270(00)00258-2"},{"key":"e_1_2_5_12_1","doi-asserted-by":"publisher","DOI":"10.1152\/jn.00051.2005"},{"key":"e_1_2_5_13_1","doi-asserted-by":"publisher","DOI":"10.1002\/mds.22573"},{"key":"e_1_2_5_14_1","doi-asserted-by":"publisher","DOI":"10.1007\/s004210050662"},{"key":"e_1_2_5_15_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10439-016-1765-5"},{"key":"e_1_2_5_16_1","doi-asserted-by":"publisher","DOI":"10.1186\/1743-0003-7-35"},{"key":"e_1_2_5_17_1","doi-asserted-by":"publisher","DOI":"10.1152\/jn.00247.2015"},{"key":"e_1_2_5_18_1","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.2611-14.2014"},{"key":"e_1_2_5_19_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cub.2016.02.030"},{"key":"e_1_2_5_20_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pcbi.1003944"},{"key":"e_1_2_5_21_1","doi-asserted-by":"publisher","DOI":"10.1111\/joa.12299"},{"key":"e_1_2_5_22_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1992.sp019431"},{"key":"e_1_2_5_23_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-319-46669-9_24"},{"key":"e_1_2_5_24_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10827-013-0491-3"},{"key":"e_1_2_5_25_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10827-016-0627-3"},{"key":"e_1_2_5_26_1","doi-asserted-by":"publisher","DOI":"10.1093\/brain\/102.3.509"},{"key":"e_1_2_5_27_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.clinph.2009.10.015"},{"key":"e_1_2_5_28_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1050-6411(02)00034-2"},{"key":"e_1_2_5_29_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbiomech.2011.07.003"},{"key":"e_1_2_5_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ifacol.2015.12.324"},{"key":"e_1_2_5_31_1","doi-asserted-by":"publisher","DOI":"10.1088\/1741-2552\/aa59bd"},{"key":"e_1_2_5_32_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1982.sp014140"},{"key":"e_1_2_5_33_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-8749.2000.tb00709.x"},{"key":"e_1_2_5_34_1","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-4598(200006)23:6<954::AID-MUS17>3.0.CO;2-0"},{"key":"e_1_2_5_35_1","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1998.85.2.398"},{"key":"e_1_2_5_36_1","doi-asserted-by":"publisher","DOI":"10.1109\/10.581944"},{"key":"e_1_2_5_37_1","doi-asserted-by":"publisher","DOI":"10.3389\/fnagi.2015.00151"},{"key":"e_1_2_5_38_1","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.0240-15.2015"},{"key":"e_1_2_5_39_1","doi-asserted-by":"publisher","DOI":"10.3389\/fncom.2016.00086"},{"key":"e_1_2_5_40_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.clinph.2014.11.022"},{"key":"e_1_2_5_41_1","doi-asserted-by":"publisher","DOI":"10.1111\/apha.12255"},{"key":"e_1_2_5_42_1","doi-asserted-by":"publisher","DOI":"10.3389\/fncom.2012.00066"},{"key":"e_1_2_5_43_1","doi-asserted-by":"publisher","DOI":"10.1038\/scientificamerican0371-65"},{"key":"e_1_2_5_44_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1970.sp009018"},{"key":"e_1_2_5_45_1","doi-asserted-by":"publisher","DOI":"10.1249\/00003677-198401000-00008"},{"key":"e_1_2_5_46_1","doi-asserted-by":"publisher","DOI":"10.1093\/brain\/123.8.1545"},{"key":"e_1_2_5_47_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.clinph.2007.06.009"},{"key":"e_1_2_5_48_1","doi-asserted-by":"publisher","DOI":"10.1142\/S0219635211002786"},{"key":"e_1_2_5_49_1","doi-asserted-by":"publisher","DOI":"10.1152\/jn.00868.2005"},{"key":"e_1_2_5_50_1","doi-asserted-by":"publisher","DOI":"10.1007\/s002210000534"},{"key":"e_1_2_5_51_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00221-009-1985-0"},{"key":"e_1_2_5_52_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4939-3267-2_3"},{"key":"e_1_2_5_53_1","doi-asserted-by":"publisher","DOI":"10.1093\/brain\/121.12.2381"},{"key":"e_1_2_5_54_1","doi-asserted-by":"publisher","DOI":"10.5772\/50639"},{"key":"e_1_2_5_55_1","doi-asserted-by":"publisher","DOI":"10.1016\/0006-8993(85)90632-8"},{"key":"e_1_2_5_56_1","doi-asserted-by":"publisher","DOI":"10.1523\/JNEUROSCI.5537-09.2010"},{"key":"e_1_2_5_57_1","doi-asserted-by":"publisher","DOI":"10.1152\/jn.91041.2008"},{"key":"e_1_2_5_58_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.2000.t01-1-00271.x"},{"key":"e_1_2_5_59_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10439-008-9461-8"},{"key":"e_1_2_5_60_1","doi-asserted-by":"publisher","DOI":"10.1088\/1741-2560\/5\/2\/008"},{"key":"e_1_2_5_61_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.humov.2005.09.003"},{"key":"e_1_2_5_62_1","first-page":"CR143","article-title":"Neuromuscular control of physiological tremor during elastic load","volume":"11","author":"Takanokura M","year":"2005","journal-title":"Med Sci Monit"},{"key":"e_1_2_5_63_1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.2005.101634"},{"key":"e_1_2_5_64_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.2000.00825.x"},{"key":"e_1_2_5_65_1","unstructured":"TehraniES JalaleddiniK&KearneyRE(2013).Linear parameter varying identification of ankle joint intrinsic stiffness during imposed walking movements. In2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) pp.4923\u20134927."},{"key":"e_1_2_5_66_1","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1991.65.6.1402"},{"key":"e_1_2_5_67_1","doi-asserted-by":"publisher","DOI":"10.1088\/1741-2560\/11\/5\/056006"},{"key":"e_1_2_5_68_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0003-9993(03)00199-0"},{"key":"e_1_2_5_69_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1388-2457(01)00593-4"},{"key":"e_1_2_5_70_1","doi-asserted-by":"publisher","DOI":"10.1109\/RBME.2009.2034981"},{"key":"e_1_2_5_71_1","doi-asserted-by":"publisher","DOI":"10.1016\/0006-8993(81)90819-2"},{"key":"e_1_2_5_72_1","doi-asserted-by":"publisher","DOI":"10.1016\/0021-9290(86)90196-X"},{"key":"e_1_2_5_73_1","doi-asserted-by":"publisher","DOI":"10.1097\/00003086-198310000-00042"},{"key":"e_1_2_5_74_1","volume-title":"Introduction to Robust Estimation and Hypothesis Testing","author":"Wilcox RR","year":"2012"},{"key":"e_1_2_5_75_1","doi-asserted-by":"publisher","DOI":"10.1016\/1050-6411(94)90023-X"},{"key":"e_1_2_5_76_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00221-007-0880-9"},{"key":"e_1_2_5_77_1","doi-asserted-by":"publisher","DOI":"10.1136\/jnnp.43.3.248"}],"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2FJP274899","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/JP274899","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,2]],"date-time":"2023-09-02T14:55:18Z","timestamp":1693666518000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/JP274899"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,11,19]]},"references-count":76,"journal-issue":{"issue":"24","published-print":{"date-parts":[[2017,12,15]]}},"alternative-id":["10.1113\/JP274899"],"URL":"https:\/\/doi.org\/10.1113\/jp274899","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,11,19]]}}}