The Relationship of Trunk Muscle Activation and Core Stability: A Biomechanical Analysis of Pilates-Based Stabilization Exercise

Pilates is an effective exercise method for rehabilitating musculoskeletal disorders as its principles are based on the activation of local muscles. This study aimed to compare the subjects with and without Pilates experience to find out the effect of the experience on the core muscle activity and muscle co-contraction, and to examine the relationship between the core muscle activation level and the kinematic data. This study involved 32 subjects, including 16 experienced Pilates practitioners and 16 non-experienced subjects. The knee stretch on the reformer was performed in three different positions: flat back with a neutral pelvis, round back with posteriorly tilted pelvis (RPP), and extended back anteriorly tilted pelvis (EAP). The electromyography of the internal oblique (IO), rectus abdominis (RA), multifidus (MU), and iliocostalis lumborum (IL) muscles were measured, as well as kinematic data from a 3D motion analysis system. Compared to the non-experienced subjects, the experienced subjects activated the IO muscles more than the RA muscles, and the most significant difference was seen in the RPP position (p < 0.05). The experienced patients activated the MU muscles more often than the IL muscles, with the most significant difference observed in the RPP position and the least significant in the EAP position (p < 0.05). All kinematic data and muscle activity (IO, IO/RA ratio, MU/IL ratio) showed significant differences between the experienced and non-experienced subjects (p < 0.05). The subjects presented a moderate correlation between muscle activation and core stability. It was confirmed that the experienced Pilates practitioners activated the abdominal and low back core muscles effectively, and the stability of the pelvis and trunk were better than that of the non-experienced participants. In addition, the better the trunk stability was maintained, the larger and more accurate movement of the mobility segment was observed.

Cough-induced internal oblique hematoma

Violent or sustained cough can be associated with serious musculoskeletal complications. We report a case of a cough-induced internal oblique hematoma in an obese 73-year-old woman who was not receiving antithrombotic therapy. She had no history of trauma and presented with acute worsening pain in the right flank. She had been coughing continuously for the past month and had severe cough 2 days before the onset of pain. Ultrasonography revealed a hypoechoic mass in the right lateral abdominal wall. Unenhanced computed tomography of the abdomen showed a 7 cm × 7 cm × 4 cm hematoma in the right internal oblique muscle. The patient was managed conservatively without blood transfusion. Acute abdominal pain together with an abdominal painful mass, particularly in patients with cough, should alert physicians to the possibility of an abdominal wall hematoma.