Final answer:
The psoas major muscle attaches at vertebrae T-12 to L4 and the lesser trochanter of the femur. As part of the iliopsoas group, it aids in flexing the thigh at the hip and stabilizing the body's posture. It works together with other core muscles to support movement and maintain balance.
Step-by-step explanation:
The psoas major muscle attaches at vertebrae T-12 to L4 and the lesser trochanter of the femur. This powerful muscle is part of the iliopsoas group, which also includes the iliacus muscle. Together, these muscles play a critical role in flexing the thigh at the hip and stabilizing the body's posture.
The posterior abdominal wall is strengthened by the psoas major and other muscles such as the iliacus, quadratus lumborum, and parts of the ilia of the hip bones. It is integral to the core's function in maintaining balance and providing support for the body's movement. The iliopsoas, along with the rectus femoris, adductors, and gluteal muscles, work collaboratively to control the movements at the hip joint, highlighting their importance in daily activities such as walking and running.