This was a question from one of our techs. He was a high school student at the time and worked part-time at the PT clinic. I noticed his name on an open slot on my schedule. I was hoping to catch up on documentation but instead I worked on his hamstring.  I also showed him some hamstring strain exercises.  This is a perk of working at a PT clinic – free therapy. He did, indeed, have a hamstring injury. More specifically he had a hamstring strain in his biceps femoris. How did I know? I could feel the tear. It wasn’t a terrible injury but it would keep him out of soccer for at least a couple of weeks. Read on to learn more about hamstring strains.  Let’s start with anatomy!
What is a hamstring strain?
The hamstrings are the group of muscles on the back of the thigh. This group is made up of 3 muscles which include the semitendinosus, semimembranosus, and biceps femoris. All 3 of these muscles attach to the ischial tuberosity (the sit bone) and then travel down the thigh and attach below the knee. The biceps femoris is the hamstring muscle that is on the outside of the back of the thigh and attaches to the fibular head (the top of the smaller lower leg bone). The semimembranosus is the hamstring muscle that is on the inside of the back of the thigh. It attaches to the upper inner part of the tibia (shin bone). In between the biceps femoris and the semimembranosus is the semitendinosus. This muscle attaches onto an area called the pes anserine that is on the front and inner part of the upper shin bone. Together these muscles work together to extend the hip (move it behind the body) and bend the knee.
A strain is an injury that causes damage to the muscle fibers of one or more of the three hamstring muscles. This injury is the result of excessive force generation while the muscle is in a stretched position. Hamstring strains usually occurs while running or sprinting at high speeds with sudden starts or changes in direction. It can also occur with hurdling, kicking, or heavy lifting.
Not all strains are the same. Some are more severe than others. There are grades that describe the severity of a strain.
- Grade 1: This is the mildest strain. Only a few muscle fibers are damaged. Walking will, most likely, not be affected. It feels like a pulled or cramping muscle. Symptoms can last for a few days.
- Grade 2: This is a moderate strain with about half of the muscle fibers torn. Walking will be affected. Acute pain and swelling are present.
- Grade 3: This is a severe strain in which more than half to all (complete rupture) of the muscle fibers are torn. There will be massive swelling and pain. Person will need crutches to aid in walking. Symptoms can last for weeks.
What does it feel like when the hamstring tears?
There are several symptoms of a hamstring strain. These include:
- Sudden onset of pain in the back of the thigh
- There can be minimal to severe pain
- A popping or tearing sensation can be felt
- Swelling and bruising – These might not be present in milder strains and might be delayed by several days in more severe strains.
- Tenderness in area of the muscle tear
- Decreased hamstring strength
- Decreased hamstring flexibility
- Limping
- Pain with sitting
- Pain with straightening the knee
What are the risk factors for hamstring strains?
There are several risk factors which increase the chances of a hamstring strain. These include:
- Previous hamstring injury
- Increasing age
- Tight hamstrings
- Poor core strength
- Previous calf injury
- Previous knee injury
- Tight hip flexors and quadriceps
- Muscle fatigue
- Skipping proper warm up before activity
Hamstring injuries peak at ages 16 to 25. This is mostly related to sports. Sports that require rapid movements that occur at a high speed are the most likely to lead to hamstring tears. These include soccer, football, and track and field sports. Our tech that strained his hamstring was 18 years old and was an active soccer player for his high school and a club team. Shortly after recovering from his original hamstring strain, he strained his other hamstring.
Who should I see to treat a hamstring strain?
- Physical therapist – If the injury is mild, it will probably heal on it’s own with a few days of rest and ice. However for moderate to severe strains, physical therapy is going to be needed. Physical therapists can aid in decreasing pain and swelling, increasing strength and flexibility, and returning to sport safely. Hamstring injuries are very slow to heal and nearly one-third of these injuries reoccur within a year of returning to sport. 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.
- Orthopedist – If a complete rupture of the tendon or muscle is suspected then the person would need to see an orthopedist. Imaging would be required to confirm the complete tear. The orthopedist would discuss options including surgical repair if the complete tear was present.
What can I do at home?
Most mild strains can be managed at home. Even if the injury is of higher grade, there are still things that you can do to help the healing process.
- Relative rest – Resting the area to decrease further pain and damage from occurring and allowing healing to begin is very important. This would include a few days to a week of relative rest to allow a mild injury to heal. This could include several weeks or months for a more severe injury. Because of the high incidence of reoccurrence, it is important that the hamstring has the appropriate strength and endurance to return to the activity or sport in which it was injured.   Performing other activities while the hamstring is healing is a good way to keep up cardiovascular and muscle strength. Walking, swimming and gentle biking would be good alternative activities that do not put much stress through the hamstring.
- Ice – Ice can help decrease the pain and swelling at the hamstring. Ice the painful area for 15 to 20 minutes at a time. I would recommend using an ice pack several times per day if the pain is constant or there is still swelling present. Ice immediately after activity.
- Stretching – Stretching the hamstrings is important. This allows the fibers to lengthen as they heal. Stretching will be very gentle after the initial injury. Also it is important to stretch the hip flexors, calves, and quadriceps. See the video below.
- Strengthening – It is important to begin with gentle strengthening of the hamstrings and then progress to more aggressive and sport-specific exercises. It is also important to strengthen the core muscles, as well as, the other muscles in the hips and thighs.  Using a loop resistance band can help increase difficulty and strength.  See the videos below.
In review
- The hamstrings are a group of three muscles located on the back of the thigh.
- A hamstring strain is an injury in which one or more of the three hamstring muscles are torn.
- Hamstring strains are very common in sports especially if high intensity running is involved.
- There are grades of hamstring strains with grade 1 being very mild and grade 3 being severe.
- Physical therapy is needed for moderate to severe strains.
- An orthopedist will need to be consulted if a complete tear is suspected.
- Reoccurrence after return to sport is very common.
- There are many things that you can do to help your hamstring.
- 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://www.physio-pedia.com/Hamstring_Strain
https://www.choosept.com/guide/physical-therapy-guide-hamstring-injuries