"eccentric contraction" meaning in English

{
  "forms": [
    {
      "form": "eccentric contractions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "eccentric contraction (plural eccentric contractions)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Anatomy",
          "orig": "en:Anatomy",
          "parents": [
            "Biology",
            "Medicine",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The tensioning of a muscle as it is being lengthened"
      ],
      "id": "en-eccentric_contraction-en-noun-GWKds3qL",
      "links": [
        [
          "anatomy",
          "anatomy"
        ],
        [
          "tensioning",
          "tensioning"
        ],
        [
          "muscle",
          "muscle"
        ],
        [
          "lengthen",
          "lengthen"
        ]
      ],
      "raw_glosses": [
        "(anatomy) The tensioning of a muscle as it is being lengthened"
      ],
      "topics": [
        "anatomy",
        "medicine",
        "sciences"
      ]
    }
  ],
  "word": "eccentric contraction"
}

{
  "forms": [
    {
      "form": "eccentric contractions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "eccentric contraction (plural eccentric contractions)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Anatomy"
      ],
      "glosses": [
        "The tensioning of a muscle as it is being lengthened"
      ],
      "links": [
        [
          "anatomy",
          "anatomy"
        ],
        [
          "tensioning",
          "tensioning"
        ],
        [
          "muscle",
          "muscle"
        ],
        [
          "lengthen",
          "lengthen"
        ]
      ],
      "raw_glosses": [
        "(anatomy) The tensioning of a muscle as it is being lengthened"
      ],
      "topics": [
        "anatomy",
        "medicine",
        "sciences"
      ]
    }
  ],
  "word": "eccentric contraction"
}