Hip pain and hip instability | What happens if hip muscles are weak?
Ross Hauser, MD., Danielle Matias, PA-C
For many years we have been treating patients and athletes who were not initially responding to physical therapy or other exercise programs to strengthen their core, low back, hip and pelvic structures. We found many of them searching online for answer as to why their exercise programs were not making their muscles strong. I hope this article helps answers some of these questions for you.
What I will present here in this article is that hip muscles cannot be made stronger if ligament and tendon damage exists. The hip ligament damage and weakness causes hip instability which contributes to the muscles inability to find resistance to grow. Further the tendon attachments of the muscles, the strong tissue that holds the muscle to the bone, when weakened and damaged, will prevent the muscle from achieving a full workout and will in fact retard muscle growth. I invite you to explore this subject further with my articles Why physical therapy and yoga may not help your low back pain and Why physical therapy and exercise may not help your hip pain.
Hip muscles weakness comes from hip instability
In the image below we see the ligaments of the hips, pelvis and lower back. Ligaments hold the skeletal structure together. Hip instability occurs because of the inability of the hip joint connectors, that is the hip ligaments, the soft tissues that connect and hold the hip and pelvic bones in place, to actually be strong enough to hold the hip in proper alignment or in a stable, strong position in relation to the lumbar spine, pelvis, and knees. If the ligaments are weak or damaged, the bones float closer and further away from each other, pulling and stretching on the muscles and tendons in an unnatural way. This constant wear and tear leads to muscle spasms and muscle and joint weakness.
The muscles of the hip and attachments to the pelvis
A September 2022 paper in the medical journal Radiographics (5) discusses the common problems of hip, and pelvic tendon tears and pathology. The also discuss the challanges a radiologist may have in reading the MRI correctly. The authors write: “While the imaging findings of pelvic tendon injury mirror those at (other) body sites, radiologists may be less familiar with tendon anatomy and pathologic conditions at the pelvis.” The authors then explain the muscle attachments at hip and pelvis:
The bony pelvis serves as the attachment site for a large number of powerful muscles and tendons that drive lower extremity movement. Organizing the pelvic tendons into groups that share a common function and anatomic location helps the radiologist systematically evaluate these structures for injury, which can be caused by repetitive stress, acute trauma, or failure of degenerated tissues.
Tears of the anteromedial adductors (mid thigh muscles in the front, we further discuss the adductor muscles below) around the pubic symphysis and anterior flexors traversing anterior (in front of the leg. Flexors are muscles that pull the knee closer to the chest as in running, walking, stairs, and various other activities) to the hip principally affect younger male athletes. (Please see my article Pubic symphysis injury in Male Athletes does this ever heal?)
Tears of the lateral abductors (side muscles and posterior extensors (primary hip extensors are the gluteus maximus and the hamstrings) are more common in older individuals with age-related tendinosis.
The deep external rotators are protected and rarely injured, although they can be impinged. (A January 2021 paper (6) in the European Journal of Anatomy however says this: “The six deep external rotator muscles of the hip (piriformis, quadratus femoris, obturator internus, obturator externus, superior gemellus, and inferior gemellus play a role in both hip stabilization and rotation and are damaged and relocated during total hip arthroplasty surgery.”)
In the image below let’s specifically look at where the muscle ends and “turns white” the attachment to the bone. That is the tendon. A strong, stretchy band of connective tissue that translates the muscle’s power to movement. When the tendons are damaged, the base of muscle resistance is weakened or even non-existent. Muscles begin to atrophy.
The primary roles of the muscles of the hip are to assist in movement and to create internal forces to balance the external forces that act on the joint. This balance is key to the stability of the hip, as it is a prominent weight-bearing joint. The muscles of the hip can be clustered into groups based upon their orientation and function, as described below.
Because the hip joint is one of the main weight-bearing joints that allows us humans to have an upright posture and walk on two legs, it is surrounded by powerful muscles. When all these structures work in a coordinated manner, the hip joint has considerable stability, strength, and flexibility.
The configuration of the hip joint, the position of the femoral head deep within the acetabulum (hip socket), the strength of the dynamic and static stabilizing ligaments, and the forces of the muscles connected to the hip make the healthy hip very stable. Why then is hip instability, which causes pain and limitations in movement, so common?
The abductor muscle group
The posterior muscle group (gluteal and hamstring muscles) functions to extend and abduct the thigh at the hip. The gluteus muscle group includes the gluteus maximus, gluteus medius, and gluteus minimus muscles. The hamstrings group is comprised of the biceps femoris, semimembranosus, and semitendinosus muscles. Also included in this group is the tensor fascia lata.
The motion of lifting your leg away from your body is the result of the movement and power of the abductor muscle group.
In my article Comparing Gluteus Medius Tendinopathy Injections and Surgery Outcomes I discuss common patient stories of gluteus medius tendinopathy. Many of these people have stopped responding to anti-inflammatories and physical therapy. After referral to a specialist, if they are limping they are diagnosed with Trendelenburg gait or gluteus medius limp and they get more medications including anti-depressant medications and stronger pharmacology treatments. Their conditions may worsen and their tendinopathy is now making their lower back, knee and ankle hurt worse.
In the above article I give An introduction to cortisone injections, Platelet Rich Plasma injections and Prolotherapy injections. These injections are also discussed below.
Gluteus maximus: The gluteus maximus is the largest muscle in the body and gives shape and structure to the buttocks. This muscle extends and helps rotate the thigh when force is required for movement, such as when climbing stairs or walking uphill. It originates from the posterior aspect of the pelvis and coccyx (tailbone) and attaches to the femur.
Gluteus maximus injury:
- There are three basic Gluteus maximus injury types.
- Overuse injury: For most patients we see, a chronic hip pain has developed as a result of “over doing it” and “continuing to overwork the muscle group.” Micro instability or tears in the gluteus maximus tendon can develop causing pain and weakness.
- Long-term and chronic hip instability: When one suffers from hip dysfunction, a breakdown of normal hip function and range of motion, whether from overuse, trauma, poor posture, too much sitting, etc, the muscles weaken and break down.
- Accident or blunt trauma: This is typically a fall or a blow from a contact sport.
Symptoms of Gluteus maximus injury:
- Chronic or acute pain that radiates from side of hip into the buttocks.
- Makes sitting difficult.
- Causes limping.
- Makes hip rotation discomforting.
- Feeling of instability and weakness.
People discussing their cases:
Emails have been edited for clarity.
Not gluteus maximus, not hamstrings, now sciatic nerve entrapment or Deep gluteal syndrome
I sustained a left hip injury while sprinting. Two months later I started having localized buttock pain (at the point where the gluteus maximus meets the IT band) and nerve pain in my left foot. My MRI showed a partial hamstring tear so six months after the initial injury I had a hamstring reinsertion surgery. Unfortunately the surgery did nothing to improve my symptoms. My doctors now suspect that I have sciatic nerve entrapment in the deep gluteal space. I take painkillers every day in order to function. (This person identified themselves as an MD.)
All the pains get worse with emotional stress and distress.
I have pain in both sides of my buttocks. It started on the left side when I was using a 7 inch high wedge pillow to sleep to relieve acid reflux. I stopped using the wedge pillow, but the pain has gotten progressively worse over the last year or year and a half. It is hard to pinpoint where the pain is in my buttocks as it moves around from sit bone area to gluteus maximus area and some times into my hamstrings, especially in the left leg.
I have been doing acupuncture to try to treat the pain unsuccessfully for the pain year. I can no longer sit on my couch because the pain is so great. I can, however, sit on my office chair which has a much firmer cushion than the couch, though at times I get the pain even on the office chair.
I also have a right sacroiliac joint that gets stuck periodically which acupuncture seems to relieve. I think the extension of the joint downwards is tender to the touch and I often can’t sleep on my back because of that pain.
All the pains get worse with mental/emotional stress and distress.
Weak Gluteus maximus causes hip osteoarthritis
Doctors at the The University of Queensland in Australia studied (4) the idea that altered gluteus maximus muscle activity is a feature of severe hip osteoarthritis and further, when the muscle weakness would eventually lead to osteoarthritis. In looking at male athletes, specifically at “Footballers” or soccer players and their gait. What they noted was: “The pattern of gluteus maximus EMG relative to peak, approaching mid-stance in severe hip-related pain, is consistent with observations in severe hip osteoarthritis. This supports the hypothesis that symptom severity (pain) may influence muscle activity across the spectrum of hip degeneration. (Pain alters muscle activity which leads to hip instability and ultimately hip osteoarthritis).
Treatments for gluteus maximus tendinopathy
Gluteus maximus strengthening exercises in those with persistent lumbopelvic pain and SI joint dysfunction.
A February 2018 paper published in the International journal of sports physical therapy (2) discussed the problems of strengthening the gluteus maximus in patients with sacroiliac dysfunction. The researchers noted that while medical guidelines has emphasized the use of exercise as an intervention for individuals with lumbopelvic pain, there is limited information to guide clinicians in exercise selection for those with sacroiliac (SI) joint dysfunction. Altered function of the gluteus maximus has been found in those with SI joint dysfunction. In this paper, positive results were seen in patients to support the use of gluteus maximus strengthening exercises in those with persistent lumbopelvic pain and clinical tests positive for SI joint dysfunction.
A paper in the Journal of back and musculoskeletal rehabilitation (3) concluded that core muscle strengthening exercise along with lumbar flexibility and gluteus maximus strengthening is an effective rehabilitation technique for all chronic low back pain patients irrespective of duration (less than one year and more than one year) of their pain.
Surgery in older patients to restore muscle strength:
The gluteus maximus is used in end-stage salvage operations to try to correct hip abductor insufficiency. A November 2021 paper from a team of Greek and Swiss surgeons published in the journal Hip international (1) wrote that “The treatment options of chronic abductor insufficiency in the setting of muscle degeneration, are limited and technically demanding.” The paper itself then presented the outcomes of a salvage technique for unreconstructable, chronic abductor tears. Thirty-eight patients, average age 70, who were surgically managed for chronic abductor insufficiency. All patients had a Trendelenburg gait (walking difficulties), impaired muscle strength of abduction and fatty degeneration of muscles. They underwent transfer of a flap of the anterior third of gluteus maximus to the greater trochanter. The doctors reported this salvage technique improved the strength of abduction and functional results and reduced the level of pain in 80% of patients with chronic abductor tears. The short-term outcomes of the procedure were favorable; however, further evaluation is needed.
There is no much by way of research that is specific to gluteus maximus tendinopathy. Below we will discuss hip tendinopathy injections.
I discuss other problems associated with gluteus maximus injury in these articles below
- Diagnosis and non-surgical options for Femoroacetabular Impingement
- Piriformis Syndrome and Sciatica Pain
- Iliotibial band syndrome – Sports related knee pain
The illustration shows trochanteric bursitis. The bursal sac is inflamed because the gluteus medius muscle is irritating it. This occurs because the gluteus medius muscle has to contract so much to help stabilize the pelvis and hip. Why? One reason can be the underlying hip joint instability from a labral tear or ligament injury.
In our article Comparing Gluteus Medius Tendinopathy Injections and Surgery Outcomes, that when the hip goes through microinstability and then instability and the hip joint becomes unstable, the muscles, including the Gluteus Medius, try to create stability by tensing, cramping, or going into spasm. When the Gluteus Medius muscle tenses, you have a “pull” on the Gluteus Medius tendon. If the tendon is damaged, it will be very painful. That painful tendon starts sending signals to the hip and spine and knee and leg and ankle that it needs help taking some of the load. Suddenly you have pain messages going up and down your leg from the spine to the foot.
Gluteus medius injury:
Similar to injuries seen in gluteus maximus, gluteus medius injury are the results of:
- Overuse injury.
- Long-term and chronic hip instability.
- Accident or blunt trauma.
Symptoms of Gluteus medius injury:
- Chronic or acute pain that radiates from side of hip into the buttocks.
- Makes sitting difficult.
- Causes limping.
- Makes hip rotation discomforting.
- Feeling of instability and weakness.
The connection of Gluteus medius injury to Greater trochanteric pain syndrome
A 2019 study (4) offered a review of the problems of gluteus medius tendinopathy and Greater trochanteric pain syndrome. “. . . a growing body of literature has demonstrated gluteus medius tendinopathy and tearing is present in many cases of Greater trochanteric pain syndrome. Pathology of the gluteus medius can result in significant hip pain, loss of motion, and decreased function. Affected patients characteristically have symptoms including lateral hip pain and a Trendelenburg gait, which may be refractory to conservative management such as non-steroidal anti-inflammatory drugs (NSAIDs), physical therapy, and injections. In these cases, both open and arthroscopic repair techniques have been described.”
The gluteus minimus is the deepest and smallest of the superficial gluteal muscles. Like the gluteus medius, it stabilizes the pelvis during walking and abducts and rotates the thigh medially. It originates from the pelvis and attaches to the femur. The gluteus minimus, medius and tensor fascia lata move the lower limb away from the midline of the body to keep the pelvis level and offset the imbalance generated by having most of the body’s weight on one leg.
Hamstrings: The three hamstring muscles work to extend and laterally rotate the hip, although their main action is to flex the knee. The biceps femoris is a double-headed muscle that originates from the pelvis (ischium) and femur and attaches to the fibula. The semimembranosus muscle originates at the ischial tuberosity and attaches at the tibia. The semitendinosus muscle shares its origin with the biceps femoris at the ischium and attaches at the tibia.
Please see my related articles: Pes Anserine bursitis, Pes anserine syndrome lower hamstring tendonitis, and MCL sprain and Why are hamstring injuries so difficult to treat?
Tensor Fascia Lata: The tensor fascia lata works with the gluteus maximus and contributes to balancing of the pelvis when walking, standing, or running. It originates from the iliac crest and anterior superior iliac spine and is continuous with the iliotibial tract (IT band) that attaches at the tibia.
Adductor Muscle Group
The adductor group moves the thigh toward the body’s midline, though some of the muscles in the group have other functions. This group is located on the medial side of the thigh and includes the adductor longus, adductor magnus, adductor brevis, pectineus, and gracilis muscles. (Note: the pectineus act as adductor muscles but is much more important as a hip flexor).
Adductor longus: The adductor longus is a large muscle that lies flat and covers the adductor mangus and adductor brevis muscles. This muscle is responsible for adduction and medial rotation of the thigh. It originates from the pubis and broadly attaches to the femur.
Adductor magnus: The adductor magnus is the largest and most posteriorly located of the adductor group muscles. It extends, adducts, and flexes the thigh. The adductor mangus originates from the pubis and attaches to the femur.
Adductor brevis: The adductor brevis is a short muscle that is located under the adductor longus. It adducts the thigh. It originates from the pubis and attaches to the femur.
Gracilis: The gracilis is the most superficial and medial of the adductor group muscles. Crossing both the hip and knee joints it causes adduction of the thigh at the hip and flexion of the thigh at the knee. It originates from the pubis and attaches to the tibia.
Lateral Rotator Muscle Group
This muscle group rotates the thigh laterally, away from the body’s midline. All of the lateral rotator group muscles are located deeply in the thigh and include the piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, and quadratus femoris.
Piriformis: The piriformis is the most superior of the lateral rotator group muscles. It performs lateral rotation and abduction of the thigh at the hip.
Obturator internus: The obturator internus lines the internal wall of the pelvis. It also rotates the thigh laterally and abducts it at the hip.
Obturator externus: The obturator externus is a small muscle located in the medial thigh that rotates the thigh laterally. It originates from the pubis and attaches to the femur.
Gemelli: The gemelli are two narrow and triangular muscles, separated by the obturator internus tendon that rotate the thigh laterally and abducts it at the hip.
Quadratus femoris: The quadratus femoris is a flat, square-shaped muscle. Of the muscles of the lateral rotator group, this muscle is the deepest. It lies below the gemelli and obturator internus. The quadratus femoris muscle is responsible for lateral rotation of the thigh at the hip and helps to extend the lower leg at the knee.
Hip Flexor Muscle Group
This muscle group flexes the hip to bring the knee upward. These muscles are located at the anterior thigh and include the psoas major, iliacus, sartorius, and pectineus muscles.
Psoas major: The psoas major is located near the middle of the back near the spine. The iliacus and psoas major comprise the iliopsoas group. The psoas major originates from the base of the spine and integrates with the iliacus to attach to the femur.
Iliacus: The iliacus is a large muscle that lines the interior of the pelvis. The iliacus and psoas major comprise the iliopsoas group. The iliacus oiginates from the pelvis and the base of the spine, combining with the psoas major to attach to the femur.
Sartorius: The sartorius is the longest muscle in the body. It is located in the thigh. The Sartorius assists in flexion, abduction and rotation of the thigh at the hip joint. It originates from the pelvis and attaches to the tibia.
Pectineus: The pectineus muscle is a large flat muscle found in the thigh that assists with adduction and flexion at the thigh at the hip joint. It originates from the pelvis and attaches to the femur.
How muscles heal, how muscles weaken
Muscles grow by being slightly injured by the exercise or activity they are subjected to and by the boy’s quick healing response. The body’s quick healing response is controlled inflammation. Controlled inflammation is the process by which joint cells create new muscle tissue, whereas chronic inflammation is caused by too much injury to the muscle. In chronic inflammation joint cells die and tissues degenerate. When a person exercises, the muscle tissue and cells naturally get stretched and injured and through the rebuilding inflammatory process can grow and hypertrophy (muscles get bigger). Thus, controlled exercise increases the health and vitality of the muscles.
As mentioned previously, the ligaments that surround the hip work as a ‘mesh’ network. Injury to one will overload the surrounding ligaments until eventually, they all become weak and lax. Over time, this can increase the pressure on the surrounding muscles and tendons (including the gluteal tendons) and cause them to degenerate as well. This can explain why patients may state that their pain started in the anterior hip, but over time has ‘spread’ and now pain is felt throughout the whole hip.
Ross Hauser, MD and Danielle Matias, PA-C discuss the types of cases we see at Caring Medical Florida with chronic tight hip flexors, snapping hip, and other instability-related conditions.
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