{
  "abstract": "Joint damage may result from different conditions, including osteoarthritis, rheumatoid arthritis, infection, and haemophilic arthropathy. Long-term effects of resistance training in individuals with massive joint destruction remain poorly documented. We report a case of a patient with haemophilia and massive joint destruction who completed a two-year home-based knee-extension programme. Training was performed twice weekly and included biofeedback-guided isometric knee extension at 80% of maximal voluntary isometric strength, followed by a closed-chain exercise using elastic resistance. Structural knee damage and quadriceps cross-sectional area (CSA) were assessed using computed tomography (CT). Pain, knee-extension strength, quadriceps CSA, and 30-s sit-to-stand performance were assessed at baseline and at two-year follow-up. Pain during active knee extension decreased from 6/10 to 2/10, and pain during daily activities decreased from 6/10 to 4/10. Knee-extension strength increased from 7 kgf to 20 kgf, representing a 186% increase. The 30-s sit-to-stand performance improved from 14 to 22 repetitions and estimated relative sit-to-stand muscle power increased from 3.4 to 5.3 W/kg, representing a 57% increase. Notably, quadriceps CSA increased by only 6% (from 1954.9 to 2078.6 mm²). No bleeding episodes or other adverse events were reported. After two years of strength training, marked gains in muscle strength and power were observed despite a small increase in quadriceps cross-sectional area. This case report highlights the need for future long-term follow-up studies of strength training in individuals with advanced joint damage.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Physical Therapy, Faculty of Medicine, University of Chile, Santiago 8380453, Chile.",
    "Transversal Group on Rare, Uncommon, and Orphan Diseases (GERPOH-UChile), Faculty of Medicine, University of Chile, Santiago 8380453, Chile.",
    "Kinesiology Unit, Hospital San José, Santiago 8380419, Chile.",
    "Traumatology Unit, Hospital San José, Santiago 8380419, Chile.",
    "Exercise Intervention for Health Research Group (EXINH-RG), Department of Physiotherapy, University of Valencia, 46010 València, Spain."
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Carlos Cruz-Montecinos"
    },
    {
      "affs": [
        0
      ],
      "name": "Rodrigo Núñez-Cortés",
      "orcid": "0000-0002-4068-9338"
    },
    {
      "affs": [
        0,
        2
      ],
      "name": "Pablo Becerra-Yañez",
      "orcid": "0009-0000-4330-8740"
    },
    {
      "affs": [
        3
      ],
      "name": "Andrés Oyarzún"
    },
    {
      "affs": [
        4
      ],
      "name": "Joaquín Calatayud",
      "orcid": "0000-0002-8670-8346"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4g3jv7q28675d.bib",
  "cited_by": 0,
  "doi": "10.3390/muscles5040075",
  "fulltext_url": "https://europepmc.org/articles/PMC13692431",
  "id": "4g3jv7q28675d",
  "issns": [
    "2813-0413"
  ],
  "landing_url": "https://europepmc.org/article/MED/42924647",
  "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",
      "2707|Cardiovascular and exercise physiology"
    ]
  ],
  "openalex": "W7221600355",
  "pdf_url": "https://europepmc.org/articles/PMC13692431?pdf=render",
  "pmcid": "PMC13692431",
  "pmid": "42924647",
  "published": "2026-10-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4g3jv7q28675d.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:33Z",
      "native_id": "MED:42924647",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42924647"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2707|Cardiovascular and exercise physiology",
      "subfield": "general"
    }
  ],
  "title": "Muscle Strength and Power Improve Despite Small Increase in Quadriceps Cross-Sectional Area in Massive Knee Joint Destruction: A Two-Year Follow-Up Case Report.",
  "title_text": "Muscle Strength and Power Improve Despite Small Increase in Quadriceps Cross-Sectional Area in Massive Knee Joint Destruction: A Two-Year Follow-Up Case Report.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:33Z",
  "url": "https://research.draconitic.com/paper/4g3jv7q28675d",
  "venue": "Muscles (Basel, Switzerland)",
  "versions": []
}