Internal Obliques

This course describes the anatomy and integrated function of the internal oblique muscle (a.k.a. the obliques, internal abdominal oblique, oblique muscles, deep core muscles). The internal obliques originate on the inguinal ligament and iliac crest and insert into the linea alba (sharing an attachment with the transverse abdominis). This muscle is located in the lateral abdominal wall, deep to the external obliques, but superficial to the transverse abdominis. Research is not available on the fiber type composition of the oblique muscles; however, it may be reasonable to suggest that the proportion of type I muscle fibers and type II muscle fibers is similar to the rectus abdominis and fairly even. The internal oblique muscles cross the torso and pelvis, influencing motion of the pelvis, thoracic spine, lumbar spine, and ribs. The obliques are the primary rotators of the lumbar spine, will contribute to flexion during bilateral contraction, and lateral flexion during unilateral contraction, as well as a posterior pelvic tilt, a lateral pelvic tilt, and increasing intra-abdominal pressure and spine/pelvis stability. This course also describes the role of the internal obliques in facet joint arthrokinematics, fascial integration (connective tissue relationship between abdominal wall muscles), postural dysfunction, and subsystem integration. Sports medicine professionals (personal trainers, fitness instructors, physical therapists, massage therapists, chiropractors, occupational therapists, athletic trainers, etc.) must be aware of the integrated function of the internal oblique muscles for the detailed analysis of human movement, and the development of sophisticated exercise programs and therapeutic (rehabilitation) interventions. Further, this course is essential knowledge for future courses discussing injury prevention and physical rehabilitation /physical therapy (e.g. “weak core,” abdominal wall pain, diastasis recti, hip flexor strain, sports hernias, groin injury, anterior pubic ligament injury, low back pain), the synergistic function of the internal obliques (e.g. connective tissue and synergistic relationship between bilateral contraction of the internal obliques, intrinsic stabilization subsystem integration, and hip flexor activity) and internal oblique muscle specific exercises and techniques for enhancing sports performance (e.g. ensuring ideal oblique length for optimal core stability, strength, power, hypertrophy, etc.).

Brookbush Institute’s most recommended techniques for the Internal Obliques (see videos below):

• Activation: Transverse Abdominis Isolated Activation (Quadrupeds)
• Activation: Quadruped Crawl
• Activation: Dynamic Quadruped Crawl

Caption: The internal oblique muscle on the torso, deep to the rectus abdominis and external oblique