{"doi":"10.1152/japplphysiol.00664.2004","title":"Twitch potentiation is greater after a fatiguing submaximal isometric contraction performed at short vs. long quadriceps muscle length","abstract":"<jats:p> Endurance time of a submaximal sustained contraction is longer when the muscle is fatigued in a shortened position. The aim of the present study was to compare central and peripheral mechanisms of fatigue after an isometric contraction of the knee extensor muscles performed at 20% maximal voluntary contraction (MVC) at two knee angles (35°, short length vs. 75°, long length; 0° = full extension) until exhaustion. Eleven men (24 ± 4 yr) attended two experimental randomized sessions. Endurance time was greater at 35° compared with 75° (974 ± 457 vs. 398 ± 144 s; P &lt; 0.001) despite a similar reduction in knee extensor MVC (−28.4 ± 16.0%, P &lt; 0.001 vs. −27.6 ± 18.8%, P &lt; 0.001, respectively). Voluntary activation level was similarly depressed after the fatiguing contraction performed at the two muscle lengths (−19 ± 16.7% at 35°, P &lt; 0.01 vs. −13.7 ± 14.5% at 75°, P &lt; 0.01). After the fatiguing contraction, peak twitch potentiation was observed only at the short length (+31.8 ± 17.6% at 35°, P &lt; 0.01 vs. +6.4 ± 21.3% at 75°, P &gt; 0.05), whereas M-wave properties were similarly altered for the two angles. These results suggest that 1) central fatigue at task failure for a sustained isometric contraction was not dependent on the muscle length, and 2) the longer endurance time of a sustained isometric contraction performed at a shortened length is related to potentiation. It is suggested that the greater endurance time of a sustained isometric contraction observed at 35° is related to the occurrence of potentiation at this short length, because central fatigue is similar at task failure for both tasks. </jats:p>","journal":"Journal of Applied Physiology","year":2005,"id":679878,"datarank":0.6862066467755076,"base_score":4.574710978503383,"endowment":4.574710978503383,"self_citation_contribution":0.6862066467755076,"citation_network_contribution":0.0,"self_endowment_contribution":0.6862066467755076,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":96,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":331493,"name":"Nicola A. Maffiuletti","orcid":"0000-0001-5670-286X","position":1,"is_corresponding":false},{"id":1776385,"name":"Yves Ballay","orcid":null,"position":2,"is_corresponding":false},{"id":150713,"name":"Romuald Lepers","orcid":"0000-0002-3870-4017","position":3,"is_corresponding":false},{"id":666768,"name":"Nicolas Place","orcid":"0000-0001-9044-0621","position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Twitch potentiation is greater after a fatiguing submaximal isometric contraction performed at short vs. long quadriceps muscle length","abstract":"<jats:p> Endurance time of a submaximal sustained contraction is longer when the muscle is fatigued in a shortened position. The aim of the present study was to compare central and peripheral mechanisms of fatigue after an isometric contraction of the knee extensor muscles performed at 20% maximal voluntary contraction (MVC) at two knee angles (35°, short length vs. 75°, long length; 0° = full extension) until exhaustion. Eleven men (24 ± 4 yr) attended two experimental randomized sessions. Endurance time was greater at 35° compared with 75° (974 ± 457 vs. 398 ± 144 s; P &lt; 0.001) despite a similar reduction in knee extensor MVC (−28.4 ± 16.0%, P &lt; 0.001 vs. −27.6 ± 18.8%, P &lt; 0.001, respectively). Voluntary activation level was similarly depressed after the fatiguing contraction performed at the two muscle lengths (−19 ± 16.7% at 35°, P &lt; 0.01 vs. −13.7 ± 14.5% at 75°, P &lt; 0.01). After the fatiguing contraction, peak twitch potentiation was observed only at the short length (+31.8 ± 17.6% at 35°, P &lt; 0.01 vs. +6.4 ± 21.3% at 75°, P &gt; 0.05), whereas M-wave properties were similarly altered for the two angles. These results suggest that 1) central fatigue at task failure for a sustained isometric contraction was not dependent on the muscle length, and 2) the longer endurance time of a sustained isometric contraction performed at a shortened length is related to potentiation. It is suggested that the greater endurance time of a sustained isometric contraction observed at 35° is related to the occurrence of potentiation at this short length, because central fatigue is similar at task failure for both tasks. </jats:p>","is_dataset_classified":null,"base_score":0.0,"endowment":0.0,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"15475602","pmcid":null,"openalex_id":null,"authors":[],"funders":[],"total_grants":0,"fwci":null,"citation_percentile":null,"influential_citations":0,"citation_trend":[],"oa_status":"closed","license":null,"oa_locations":[{"url":"https://www.physiology.org/doi/pdf/10.1152/japplphysiol.00664.2004","host_type":"publisher"}],"fields_of_study":[],"mesh_terms":["Knee","Muscle, Skeletal","Humans","Electric Stimulation","Adaptation, Physiological","Muscle Fatigue","Physical Endurance","Isometric Contraction","Adult","Male","Physical Exertion"],"keywords":[],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-17T13:57:21.210868Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}