Objectives: To identify typical patterns of abdominal wall muscle activation in patients with diastasis recti and inguinal hernias compared to controls during the Valsalva maneuver, voluntary coughing, and physical activity. Methods: The study included 15 subjects: 5 with diastasis recti, 4 with inguinal hernias, and 6 healthy controls. The functions of rectus abdominis (RA) and external oblique (OE) muscles were measured by surface electromyography (sEMG). Using ultrasound, the thicknesses of the RA, OE, internal oblique (IO), and transversus abdominis (TA) muscles were assessed as well as the echo intensity (EI) of RA and OE. Results: We found a significant effect of the type of abdominal wall pathology on the maximum sEMG amplitude (p = 0.005). There was a reliable trend in maximum sEMG amplitude, with the highest one in diastasis recti and a significantly lower one in inguinal hernias. Duncan’s test showed a significant difference in muscle thickness, both on the right and left sides, between patients with diastasis and controls, but only on the left side between patients with diastasis and those with inguinal hernia (p < 0.05). Conclusions: The abdominal wall pathology results in a change in the function and structure of the abdominal muscles, which can be detected using electromyography and ultrasound examination. The presence of diastasis recti is accompanied by an increase in bioelectrical activity and a decrease in thickness.

Introduction . Nerve conduction study (NCS) is the main component of instrumental diagnostics of ulnar neuropathy at the elbow (UNE). In recent years, ultrasound (US) examination has become increasingly important, allowing the identification of the site of compression, dynamic examination, and assessment of the structures surrounding the nerve. Aim. To compare the results of NCS and US in patients with clinical signs of UNE. Materials and methods . The NCS and US data were analyzed in 93 patients with clinical signs of mild (86 patients) and moderate (7 patients) UNE. Standard NCS studies and US of the ulnar nerve were analyzed. Results. Electrophysiological changes corresponding to UNE were detected in 48 (51.5%) examined patients, ultrasound changes in 50 (54%). The groups with positive and negative NCS and US results did not differ in the main anthropometric characteristics and disease duration. When the left ulnar nerve is involved, nerve conduction study and ultrasoun are often positive; the presence of m. anconeus epitrochlearis in the retroepicondylar groove is often accompanied by negative nerve conduction study results. The ulnar nerve CSA is characterized by an inverse correlation with the amplitude of the ulnar nerve sensory response, motor nerve conduction velocity at the elbow and compound muscle action potential amplitude recorded from abductor digiti minimi muscle. The maximum ulnar nerve CSA at the elbow differs in patients with different UNE severity (p = 0.0001). Conclusions . In the group of patients, which was characterized by a predominance of patients with mild cubital tunnel syndrome, NCS and ultrasound results are highly consistent. The identified factorial interactions indicate the need for a comprehensive approach to diagnosing ulnar nerve lesions, taking into account the lateralization of the process and the specific anatomical features.