The gluteal group is composed of three muscles: gluteus maximus, gluteus medius, and gluteus minimus (Images 1–3). These muscles stabilize the thigh and pelvis at the hip joint. The gluteus maximus is the largest muscle in the human body and forms the contour of the buttock. It is superficial and covers much of the gluteus medius. The gluteus medius is deep to the gluteus maximus posteriorly and deep to the tensor fasciae latae anteriorly, but it is superficial laterally. It covers most of the gluteus minimus. The gluteus minimus is the deepest and smallest of the group.

Attachments
Gluteus Maximus
Origin (proximal attachment)
• Posterior iliac crest, posterolateral sacrum, and coccyx
Insertion (distal attachment)
• Iliotibial band (ITB) and the gluteal tuberosity of the femur
Gluteus Medius and Gluteus Minimus
Origin (proximal attachment)
• External ilium
Insertion (distal attachment)
• Greater trochanter of the femur

Innervation
• Inferior gluteal nerve (gluteus maximus)
• Superior gluteal nerve (gluteus medius and minimus)

Actions
All of the actions listed for the gluteal muscles occur at the hip joint. The standard actions (insertion/distal attachment moving toward origin/proximal attachment) move the thigh at the hip joint; the reverse actions (origin/proximal attachment moving toward insertion/distal attachment) move the pelvis at the hip joint.
Gluteus Maximus
• Extends the thigh.
• Laterally rotates the thigh.
• Abducts the thigh (upper fibers only).
• Adducts the thigh (lower fibers only).
• Posteriorly tilts the pelvis.
• Contralaterally rotates the pelvis.
Gluteus Medius and Gluteus Minimus
• Abduct the thigh.
• Extend the thigh (posterior fibers only).
• Flex the thigh (anterior fibers only).
• Laterally rotate the thigh (posterior fibers only).
• Medially rotate the thigh (anterior fibers only).
• Depress the same-side pelvis.
• Posteriorly tilt the pelvis.
• Anteriorly tilt the pelvis.
• Contralaterally rotate the pelvis.

Palpation
Gluteus Maximus
1. The client is prone. Place your palpating finger pads lateral to the sacrum. Place your resistance hand on the distal posterior thigh (if resistance is needed).
2. Ask the client to laterally rotate the thigh at the hip joint and then extend the laterally rotated thigh. Feel for the contraction of the gluteus maximus (Image 4). Resistance can be added, if necessary.
3. With the muscle contracted, strum perpendicular to the fibers to discern the borders of the muscle.
4. Continue palpating the gluteus maximus laterally and inferiorly (distally) to its insertion (distal attachments) by strumming perpendicular to its fibers.
5: Palpation of the middle fibers of the right gluteus medius immediately distal to the middle of the iliac crest as the client attempts to abduct the thigh at the hip joint against resistance. 6: Palpation of the anterior fibers of the gluteus medius as the client abducts and medially rotates the thigh. 7: Palpation of the posterior fibers of the gluteus medius as the client abducts and laterally rotates the thigh.

Palpation
Gluteus Medius and Minimus
1. The client is side-lying. Place your palpating finger pads just distal to the middle of the iliac crest, between the iliac crest and the greater trochanter of the femur. Place your resistance hand on the lateral surface of the distal thigh (if resistance is needed).
2. Palpating just distal to the middle of the iliac crest, ask the client to abduct the thigh at the hip joint. Feel for the contraction of the middle fibers of the gluteus medius (Image 5). If desired, resistance can be added to the client’s thigh abduction with the resistance hand.
3. Strum perpendicular to the fibers, palpating the middle fibers of the gluteus medius distally toward the greater trochanter.
4. To palpate the anterior fibers, place your palpating hand immediately distal and posterior to the anterior superior iliac spine, and ask the client to gently flex and medially rotate the thigh at the hip joint. Feel for the contraction of the anterior fibers of the gluteus medius (Image 6). Discerning the anterior fibers from the more superficial tensor fasciae latae is difficult.
5. To palpate the posterior fibers, place your palpating hand over the posterior portion of the gluteus medius, and ask the client to gently extend and laterally rotate the thigh at the hip joint. Feel for the contraction of the posterior fibers of the gluteus medius (Image 7). Discerning the posterior fibers from the more superficial gluteus maximus is difficult.
6. Palpating and discerning the gluteus minimus deep to the gluteus medius is also difficult. The gluteus minimus is thickest anteriorly. To palpate the gluteus minimus, follow the same procedure as for the gluteus medius, but try to palpate deeper.

Excerpted from Know the Body: Muscle, Bone, and Palpation Essentials (Elsevier, 2012; evolve.elsevier.com/Muscolino). Joseph E. Muscolino is a renowned massage and manual movement therapy educator and author of multiple textbooks, articles, and DVDs. He also offers a Certification in Clinical Orthopedic Manual Therapy (COMT) around the United States and overseas. Find out more about his work at www.learnmuscles.com.