As a practicing orthopedic physical therapist, I see many different patients and I am never quite sure what the next case will entail. A week or so ago, I saw a 13 year old boy with hip pain. He is a lacrosse player who plays on club teams for most of the year. He recently developed pain in the front of the hip when playing and practicing lacrosse. Upon inspection he was very tender at the area where one of the quadriceps muscles attach to the pelvis. He also just had a very large growth spurt. It all pointed toward hip apophysitis – more specifically, AIIS apophysitis. To learn more about this condition, read on. Let’s start with anatomy!
The quadriceps
The quadriceps are a group of 4 muscles on the front of the thigh. These muscles include the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. These are very large powerful muscles that activate to straighten the knee. They are extremely important in performing everyday activities such as squatting, walking, running, jumping, kicking, and many others. The rectus femoris originates at the pelvis while the other 3 originate on the femur (the thigh bone). The rectus femoris attaches to the inferior superior iliac spine (AIIS) of the pelvis. This is an area in the front of the pelvis right above the hip joint. It is the rectus femoris that is the troublemaker for AIIS apophysitis.
What is AIIS apophysitis?
There are actually several sites of hip apophysitis. This post is focused on the AIIS. AIIS apophysitis is caused by repetitive stress on the AIIS where the rectus femoris attaches to the pelvis. The AIIS is a bony protuberance on the front of the pelvis that is an inch or so lower than the big boney points that most people think of as their hips. There is a growth plate at the AIIS called an apophysis. An apophysis is an area of growth for a protuberance of bone on a larger bone. This protuberance of bone is not associated with a joint, but is usually the site of a tendon or ligament attachment. The rectus femoris tendon attaches to the AIIS at the area of the apophysis. The apophysis is the weakest area of this bone, tendon, muscle group. As the rectus femoris pulls on the AIIS over and over, it causes microvascular tears, swelling, inflammation, and pain at the apophysis.
Tell me more about AIIS apophysitis
This is an overuse injury. It occurs in active adolescent kids and is a common cause of hip pain in active teens. It normally occurs after a growth spurt. The long bones lengthen faster than the muscles can stretch. With repeated contractions of a tight quadriceps muscle, especially with sports, the rectus femoris muscle will pull on the AIIS. This causes pain and swelling at the hip because the apophysis is not fully fused to the pelvis. The good news is that this is a self-limiting condition. It will stop once the AIIS apophysis is done growing and is fused to the pelvis. The condition typically presents at ages 14-15 in females and 13-16 in males.
What are the symptoms of AIIS apophysitis?
There are several symptoms that are characteristic of AIIS apophysitis. These include:
- Pain with running and kicking
- Pain during and/or after activity
- Tenderness in the front of the hip
- Limping
- No pain or significantly less pain when getting up in the morning
What are risk factors for AIIS apophysitis?
There are several risk factors that could increase the chances of developing AIIS apophysitis. These include:
- Playing a sport with repetitive sprinting and kicking
- Being male
- Tight quadriceps
- Weakness in the hip muscles
- Recent growth spurt
What ages does AIIS apophysitis affect?
AIIS apophysitis occurs in adolescence as the AIIS has not completely hardened and the growth plates are still open. This is different for girls and boys.
- For females, ages 14-15
- For males, ages 13-16
What sports can lead to AIIS apophysitis?
Any sport that requires a lot of sprinting and kicking can lead to this condition. Unfortunately that is a lot of sports. Here is a list of common sports that might lead to AIIS apophysitis.
- Ice hockey
- Football
- Lacrosse
- Dance
- Track and field
- Soccer
- Cross country
Can anything serious happen if my kid keeps playing?
Playing through the pain can lead to an avulsion fracture. This occurs when the tendon pulls a small piece of bone away from the pelvis. The symptoms of an avulsion fracture of the AIIS are:
- Sharp, sudden pain during a forceful movement
- A “pop” might occur
- Swelling and bruising over the front of the hip
- Loss of strength in the rectus femoris
- Causes limping and difficulty lifting up the leg
How long will this last?
As previously mentioned this is a self-limiting condition. It will end when the apophysis closes and the AIIS fuses. If properly treated, the pain and inflammation can be controlled until this occurs.
Who should I see for treatment?
- Physical therapist – PT is going to be important in helping to decrease pain and swelling, increase strength and flexibility, and return to sport safely. It is important to have a physical therapist assist in determining when the person is appropriate to return to sport and provide direction in how to prevent the injury from reoccurring. This is especially important if an avulsion has occurred.
- Pediatric orthopedist – If the condition is not responding to physical therapy or an avulsion fracture is suspected then the child would need to see a pediatric orthopedist. Imaging would be required to confirm the extent of the injury. The orthopedist would discuss options for treatment.
What can we do to?
There are many things that can be done to help decrease the pain and swelling.
- Take a break – The first and best thing to do is to stop doing whatever it is that is causing the pain. This is most likely a sport. I am not saying that the child has to give up the sport but taking a break is a good idea. This might be for a week or two or, maybe, a month or two. This gives the hips some time to heal, and also time to stretch the quadriceps to decrease it’s pull on the AIIS.
- Taking a break may not be necessary if the condition is very mild. This means that the pain during and after play is very mild and goes away an hour or two after play. It also means that the pain does not cause a limp or change the way the child runs or walks. Keep in mind that mild pain can get worse if not treated so don’t ignore pain just because it is not interfering with play. Take the steps outlined to help decrease the mild pain and prevent it from becoming worse.
- Relative rest – Relative rest is participating in an activity or sport that does not bother an injury. Switching to a sport that is not so irritable to the hip is also an option. You can always return to your previous sport at a later date if desired. Also it is not advisable to have kids specialize in a sport at a young age so getting them involved in a different sport that is less irritating is a good way to practice relative rest. Swimming is very good for this condition because it is less stressful for the hips but very strengthening for the body.
- Ice – Ice is a natural anti-inflammatory and works great at decreasing pain and swelling. Ice with an ice pack immediately after activity. This includes after practice, games, or maybe running around outside. Ice for about 15 to 20 minutes. Ice several times a day if the pain is more constant and is occurring with walking or going up and down steps.
- Stretching – Stretching the quadriceps can decrease the pull on the AIIS and help decrease the pain and inflammation. The hamstrings and calf muscles are also probably tight since they have not had time to lengthen in relation to the bone growth. You will need a stretch strap, dog leash, yoga strap, or something similar. Below is a video on stretching hamstrings, quadriceps, and hip flexors.
- Strengthening – It is important to strengthen the muscles around the hip, especially in the back of the hip and thigh. This includes your gluteal muscles and the hamstrings. It is also important to strengthen your core muscles as well as the quadriceps. All these muscles will help take some of the load off the AIIS. There should be minimal soreness when performing the exercises and no pain afterwards. Using loop resistance bands , resistance bands and ankle weights can increase strength and difficulty of the exercises. See the videos below.
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
In review
- The quadriceps are a group of 4 muscles on the front of the thigh.
- These muscles include the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius.
- These are very large powerful muscles that activate to straighten the knee.
- AIIS apophysitis is caused by repetitive stress on the AIIS of the pelvis where the rectus femoris attaches.
- There is a growth plate at the AIIS called an apophysis. An apophysis is the area of growth for a protuberance of bone on a larger bone.
- As the rectus femoris pulls on the AIIS over and over, it causes microvascular tears, swelling, inflammation, and pain at the apophysis.
- This is an overuse injury. It occurs in active adolescent kids and is a common cause of hip pain in active teens.
- It is typically associated with a growth spurt.
- The condition typically presents at ages 14-15 in females and 13-16 in males.
- Any sport that requires a lot of sprinting and kicking can lead to this condition.
- Playing through the pain can lead to an avulsion fracture.
- This occurs when the tendon pulls a small piece of bone away from the pelvis.
- Physical therapy can be helpful to control the pain and inflammation and address strength and flexibility.
- A pediatric orthopedist would be needed if the condition is not responding to PT or an avulsion fracture is suspected.
- There are things that you can do
- Take a break
- Relative rest
- Ice
- Stretching
- Strengthening
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
Additional resources
https://sportdoctorlondon.com/hip-apophysitis/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9320601/