A total of 20 patients electively admitted for repair of a giant midline VIH, and 20 patients without hernias electively operated on for other indications are included. Exclusion criteria are pregnancy, severe heart- or lung disease, significant musculoskeletal disease, chemo- or radiotherapy within three months prior to the examination, and systemic corticosteroid medication. Oral and written informed consents are obtained from each participating patient.