Incisional Hernia and Its Influence on Abdominal Wall Strength: A Case-Control Study

Background Incisional hernia (IH) might lead to a weakened abdominal wall, potentially reducing patients' functionality. This study aims to assess abdominal muscle strength in patients with IH and compare it with that of healthy subjects. Method This prospective case-control study included 80 subjects, 40 patients diagnosed with IH (classified as W2-3 by the European Hernia Society Classification) and 40 healthy controls. IH patients were matched with those without abdominal wall disorders, based on gender, BMI, age, and body composition. Patients were assessed using a strain gauge, performing trunk isometric contractions at 90° and 45°, to measure the anterior abdominal wall and lateral abdominal musculature, respectively. Peak force and the rate of force development at 90° and 45° were compared between groups. Results Patients with IH exhibited a substantial 20% reduction in abdominal wall function. Abdominal wall strength significantly decreased in the IH group compared to controls in both the anterior abdominal wall at 90° (mean peak force: 208.61 vs. 169.2, p = 0.001; mean rate force development: 741.73 vs. 366, p = 0.003) and lateral musculature at 45° (mean peak force: 195.49 vs. 151.63, P = 0.001; mean rate force development: 552.27 vs. 302.90, p = 0.001). Regression analysis (p = 0.001, R2 = 0.43) revealed that gender (P = 0.000) and BMI (P = 0.004) significantly affected abdominal strength. For each centimeter increase in maximum hernia diameter, strength decreased by 5 newtons. Conclusions Patients with IH experience a significant decline in abdominal wall strength and rapid force production capacity compared to their healthy counterparts.