The rectus femoris muscle originates from the anterior superior iliac spine and inserts into the tibial tuberosity. Predict its main actions with only this information.

Which of the following muscles flexes the thigh, but also laterally flexes the vertebral column when its origin and insertion switch?

a. Sartorius muscle

b. Psoas major muscle

c. Iliacus muscle

d. Rectus abdominis muscle

Match the muscle with its main action:     

____Vastus medius muscle     

____Gracilis muscle     

____Gluteus medius muscle     

____Gastrocnemius muscle     

____Biceps femoris muscle     

____Tibialis anterior muscle

a. Adducts thigh

b. Extends thigh and flexes leg

c. Plantarflexes foot

d. Abducts thigh

e. Dorsiflexes foot

f. Extends leg

Explain how the diaphragm muscle is able to increase the size of the thoracic cavity even though it doesn't insert into a bone.

Why do you think that the muscles of the erector spinae and transversospinal muscle groups remain in a state of continual contraction when we are upright?

Elise is a competitive gymnast who strained muscles in her left lower limb doing a tumbling pass. She has pain with extension of her leg and inversion of her foot. Which muscles did she potentially strain?

Chris is training for his black belt in karate and is working on developing a stronger punch. Which muscles do you recommend that he strengthen to improve his punch? Explain.

Ms. Hendrix suffered a severe hip fracture that required hip replacement surgery. After an extended recovery period, she is undergoing physical therapy to regain strength and mobility.

b. Which muscles were likely affected by the hip replacement surgery, and to which parts of the bone do they attach?

Ms. Hendrix suffered a severe hip fracture that required hip replacement surgery. After an extended recovery period, she is undergoing physical therapy to regain strength and mobility.

c. Which actions could Ms. Hendrix perform to strengthen these muscles?