The Pelvic Region
The pelvic region of the trunk is the lower part of the trunk, between the abdomen and the thighs. It includes several structures:
- the bony pelvis (or pelvic skeleton), which is the part of the skeleton embedded in the pelvic region of the trunk, subdivided into:
- the pelvic girdle (i.e., the two hip bones), which connects the spine to the lower limbs, and
- the pelvic region of the spine (i.e., sacrum, and coccyx)
- the pelvic cavity, defined as a small part of the space enclosed by the bony pelvis, delimited by the pelvic brim above and the pelvic floor below; also subdivided into:
- the greater (or false) pelvis, above the pelvic brim
- the lesser (or true) pelvis, below the pelvic brim
- the pelvic floor (or pelvic diaphragm), below the pelvic cavity
- the perineum, below the pelvic floor
So, as you imagine, there are a lot of muscles in this region. Let´s focus on the muscles of the hip.Posterior muscle group
· Tensor fasciae latae muscle: Assist in keeping the balance of the pelvis while standing, walking or running. Medial rotation and flexion of the hip. Assist weakly with the extension of the knee, lateral rotation of the leg at the knee. Also stabilizes the hip and the knee during standing.
Origin: anterior aspect of iliac crest anterior superior iliac spine (ASIS)
Insertion: anterior aspect of IT band, below greater trochanterPain and symptoms associated with the Tensor Fasciae Latae muscle and Iliotibial Band – Pain in deep in the hip going down the outside of the thigh – Pain at the front of the hip joint – Discomfort sitting – When standing from a sitting position you tend to stand-up leaning forward at the waist with your knees bent. Straightening to a full standing position is slow with a feeling of stiffness as well as painful – While standing knees and hips tend to be flexed (bent) – Pain intensives when foot hits the ground while walking or running ITBS is the most common pain syndromes in runners, weight lifters, dancers, tennis players and basketball players. Pain or a stinging burning sensation is felt on the outside of the thigh down to the lower knee. Pain is more pronounced when the foot hits the ground while walking or running. Pain from trigger points in the tensor fasciae latae muscle is often diagnosed as bursitis of the hip or thinning of the hip cartilage. Activities that cause tensor fasciae latae muscle and iliotibial band muscle pain and symptoms – Too much walking when not in shape – Running – Climbing – Cycling – Dancing – Court sports (tennis, basketball, volleyball)
· Gluteus maximus: When the gluteus maximus takes its fixed point from the pelvis, it extends the acetabula femoral joint and brings the bent thigh into a line with the body. Taking its fixed point from below, it acts upon the pelvis, supporting it and the trunk upon the head of the femur; this is especially obvious in standing on one leg.
Origin: 1. outer rim of ilium (medial aspect) 2. dorsal surface of sacrum and coccyx 3. sacrotuberous ligament
Insertion: 1. IT band (primary insertion) 2. gluteal tuberosity of femurIts most powerful action is to cause the body to regain the erect position after stopping, by drawing the pelvis backward, being assisted in this action by the biceps femoris (long head), semitendinosus, semimembranosus, and adductor Magnus. The lower part of the muscle also acts as an adductor and external rotator of the limb. The upper fibers act as abductors of the hip joints. Pain and symptoms associated with the Gluteus Maximus muscle – Low back pain – Outer hip pain near and or around the joint – Pain around the tailbone – Pain and burning in the buttocks – Increased pain when walking uphill or up an incline – Inability or increased pain when you bend over to touch your toes Activities that cause gluteus maximus pain and symptoms – Jumping – Falls – Swimming especially when using the flutter kick – Climbing – Deep knee bends – Repetitive lifting of heavy objects with knees bent (this may protect your back, but puts enormous strain on the glute max) – Prolonged sitting on hard surfaces – Sitting for long periods – Prolonged sitting on a wallet
· Gluteus medius: with the leg in neutral position, it works with the gluteus minimus to pull the thigh away from the midline (abduct the thigh). During gait, supports the body on one leg, in conjunction with the tensor fasciae latae muscle to prevent the pelvis from dropping to the opposite side. With the hip flexed, it works with the gluteus minimus to rotate the hip. With the hip extended, both externally rotate the thigh.
Origin: 1. outer aspect of ilium (between iliac crest and anterior and posterior gluteal lines) 2. upper fascia (AKA gluteal aponeurosis)
Insertion: superior aspect of greater trochanterPain and symptoms associated with the Gluteus Medius muscle – Pain in the lower back around the beltline – Pain in the hip – Pain in the buttock – Pain can extend down the outside of the leg – Pain can extend into back of the leg – Pain when lying on the affected side – Pain will prevent sitting on the afflicted buttock – Pain worsens when sitting or standing for extended periods of time – Pain when sitting slouched Activities that cause gluteus medius pain and symptoms – Sitting for long periods of time with legs crossed – Standing on hard surfaces for an extended time – Walking and carrying a heavy item – Carrying a child on the hip – Always carrying heavy objects on one side such as filled buckets, heavy briefcase, etc. – Aerobic exercise – Running – Weightlifting
· Gluteus minimus: with the leg in neutral position, it works with the gluteus medius to pull the thigh away from the midline (abduct the thigh). During gait, supports the body on one leg, in conjunction with the tensor fasciae latae muscle to prevent the pelvis from dropping to the opposite side. With the hip flexed, it works with the gluteus medius to rotate the hip. With the hip extended, both externally rotate the thigh.
Origin: outer aspect of ilium (between anterior and inferior gluteal lines)
Insertion: 1. greater trochanter (anterior to medius) 2. articular capsule of hip jointPain and symptoms associated with the Gluteus Minimus muscle – Pain in buttocks – Pain on the outside of the hip – Pain in the back and outside of the thigh – Pain in the back of the calf down to the ankle – Numbness in buttocks, hip and thigh traveling down to ankle – Pain while walking – Difficulty rising from a sitting position – Difficulty crossing your legs – Pain while laying on affected side Activities that cause gluteus minimus pain and symptoms – Sitting for long periods of time with legs crossed – Sitting on a wallet in the back pocket – Walking and carrying an heavy item – Carrying a child on the hip – Limping for extended periods of time – Standing with weight unequally distributed on legs Ventral hip muscle group
· Piriformis: laterally rotates the femur with hip extension and abducts the femur with hip flexion. When the hip is flexed to 90 degrees, piriformis abducts the femur at the hip and reverses primary function, internally rotating the hip when the hip is flexed at 90 degrees or more.
Origin: pelvic surface of sacrum (anterior portion)
Insertion: medial surface of greater trochanter (through greater sciatic foramen)Pain and symptoms associated with the Piriformis muscle – Low back pain at the base of the spine – Buttock pain – Hip pain around the hip joint – Aching pain, burning or tingling sensations down into the back of the thigh which occasionally extends into the lower leg and/or sole of the foot – Pelvic pain – Difficulty or inability to cross your legs – Difficulty or inability to spreading leg side to side – Difficulty or inability to step out widely – Sitting for long periods of time increases pain and discomfort in the hip and/or back of the thigh – Lying down will often help diminish pain but will not totally alleviate it – The sciatic nerve runs under the piriformis. The piriformis muscle will sometimes agitate the nerve causing symptoms of sciatica which include pain, tingling, and numbness in the buttock, hip, back of the thigh, back of the calf which extends to the bottom of the foot. This is known as piriformis syndrome. In approximately 15% of the population, the sciatic nerve runs directly through the piriformis muscle. These people are more like to have symptoms of sciatica. – Women are more prone to problems with piriformis muscle pain. Activities that cause piriformis pain and symptoms – Activities and sports requiring quick abrupt changes in directions – Tennis – Football – Soccer – Basketball – Twisting while lifting – Sitting excessively
· External obturator muscle: acts as the lateral rotator of the hip joint. As a short muscle around the hip joint, it stabilizes the hip joint as a postural muscle.
Origin: 1. medial surface of obturator foramen 2. external surface of obturator membrane
Insertion: trochanteric fossa of femur
· Internal obturator muscle: helps laterally rotate femur with hip extension and abduct femur with hip flexion, as well as to steady the femoral head in the acetabulum.
Origin: 1. internal aspect margins of obturator foramen 2. obturator membrane
Insertion: medial aspect of greater trochanter (through lesser sciatic foramen)
· Quadratus femoris: it is a strong external rotator and adductor of the thigh, but also acts to stabilize the femoral head in the Acetabulum.
Origin: lateral aspect of ischial tuberosity
lateral aspect of ischial tuberosity
Insertion: quadrate line (along posterior aspect of femur and intertrochanteric crest)
quadrate line (along posterior aspect of femur and intertrochanteric crest)Symptoms and pain associated with the rectus femoris muscle – Knee pain that feels as if it originates under the knee cap – Pain in the front of the thigh extending down into the inside of the knee – Weak knee – Stiff knee – Inability to fully straighten knee – Pain walking down stairs – Restless Leg Syndrome – Sharp pain deep in the front of the thigh while sleeping Activities that cause rectus femoris pain and symptoms – Cycling – Climbing – Running and power walking – Swimming – Kicking a football or soccer ball – Swimming – Wearing high heel shoes – Sitting excessively Dorsal hip muscle group
· Psoas major: contributes to flexion in the hip joint. On the lumbar spine, unilateral contraction bends the trunk laterally while bilateral contraction raises the trunk from its supine position.
Origin: 1. transverse processes of L1-L5 2. vertebral bodies of T12-L4 and the intervening intervertebral discs
Insertion: iliopsoas tendon to the lesser trochanter of the femur
· Psoas minor: is a weak flexor of the lumbar vertebral column.Origin: Lateral surface bodies of T12 and L1 vertebrae and intervening intervertebral disc Insertion Pectineal line and iliopubic eminence
· Iliacus: is important for lifting (flexing) the femur forward. From its origin in the lesser pelvis, the iliacus acts exclusively on the hip joint.
inner surface of upper iliac fossa
iliopsoas tendon to the lesser trochanter of the femurPain and symptoms associated with the Iliopsoas muscles – Low back pain – Abdomen pain – Groin pain – Leg pain – Pelvic pain – Difficulty standing from a sitting position – Severe pain or inability to do sit-ups or crunches – Tendency to walk with feet turned out – Extreme dysfunction in the iliopsoas can cause pain under the shoulder blade that extends down to the top of the hip. Activities that cause iliopsoas pain and symptoms – Sitting for long periods of time – Sleeping on your side in the fetal position – Being overweight – Strenuous running – Climbing stairs – Sit ups, crunches and leg ups – Slumping posture