{
  "abstract": "Performance fatigability is characterized by a decline in the capacity to maintain force or power during sustained or repeated activity. This exploratory study quantified knee-extensor mechanical performance and rectus femoris surface electromyographic (sEMG) changes during repeated maximal isokinetic knee extensions and explored sex-related differences. Twenty-nine healthy adults (20 men, 9 women; 20-31 years) performed 30 maximal concentric knee extensions at 180°·s⁻¹. Mechanical outcomes were analyzed in all 29 participants, whereas rectus femoris sEMG outcomes were analyzed in 23 participants. Peak torque (PT) decreased by 32.75 ± 11.66% (adjusted p = 6.08 × 10⁻¹¹), work per repetition by 33.35 ± 11.97% (adjusted p = 2.12 × 10⁻¹¹), and mean frequency (MNF) by 23.44 ± 8.33% (adjusted p = 6.08 × 10⁻¹¹). RMS increased significantly from Start to End (adjusted p = 0.000639), with a mean FI-RMS of -17.12 ± 23.11%. FI-PT and FI-work were very strongly associated (ρ = 0.938, adjusted p = 3.71 × 10⁻¹³), whereas no association involving rectus femoris MNF or RMS remained statistically significant after Holm-Bonferroni correction. No statistically significant sex-related differences were detected. Repeated maximal knee extensions reduced mechanical performance and rectus femoris MNF while increasing RMS. FI summarizes Start-to-End change across the measured outcomes; its reliability and validity require further investigation.",
  "abstract_shown": true,
  "affiliations": [
    "Biomechanics Laboratory, Faculty of Sport and Movement Sciences, Levinsky-Wingate Academic College (Wingate Campus), Netanya 4290200, Israel."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Smadar Peleg",
      "orcid": "0000-0002-8088-0786"
    },
    {
      "affs": [
        0
      ],
      "name": "Ophir Ravina",
      "orcid": "0009-0000-4999-9116"
    },
    {
      "affs": [
        0
      ],
      "name": "Eitan Shemy",
      "orcid": "0009-0009-1826-5465"
    },
    {
      "affs": [
        0
      ],
      "name": "Moshe Ayalon"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/f5mqtrstwvrne.bib",
  "cited_by": 0,
  "doi": "10.3390/muscles5040072",
  "fulltext_url": "https://europepmc.org/articles/PMC13692531",
  "id": "f5mqtrstwvrne",
  "issns": [
    "2813-0413"
  ],
  "landing_url": "https://europepmc.org/article/MED/42924644",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2204|Muscle activation and electromyography studies"
    ]
  ],
  "openalex": "W7220377426",
  "pdf_url": "https://europepmc.org/articles/PMC13692531?pdf=render",
  "pmcid": "PMC13692531",
  "pmid": "42924644",
  "published": "2026-10-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/f5mqtrstwvrne.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:36Z",
      "native_id": "MED:42924644",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42924644"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "journal-openalex:F27",
      "subfield": "general"
    }
  ],
  "title": "Fatigue-Induced Changes in Knee-Extensor Mechanical Performance and Rectus Femoris Surface EMG During Repeated Isokinetic Knee Extensions.",
  "title_text": "Fatigue-Induced Changes in Knee-Extensor Mechanical Performance and Rectus Femoris Surface EMG During Repeated Isokinetic Knee Extensions.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:36Z",
  "url": "https://research.draconitic.com/paper/f5mqtrstwvrne",
  "venue": "Muscles (Basel, Switzerland)",
  "versions": []
}