The popliteus is a small muscle that runs behind the knee, and the popliteus tendon connects muscle to the thigh bone. Compared to the hamstrings (located above) and the calf (located below), it is often an overlooked injury. The hamstrings refer to three long posterior leg muscles, which are the biceps femoris, semitendinosus, and semimembranosus. These muscles start at the bottom of the pelvis, extending down the back of the thigh and along either side of the knee, to the lower leg bones. The popliteus muscle has four types of jobs, which are:
- It helps to start the motion of flexing the knee.
- It allows us to unlock and return to motion (once the leg / knee is straightened). If you have either tightness or shortening of the popliteus muscle, you would not have the full range of motion with your leg and knee.
- The last important movement the popliteus muscle helps with, is the hinge action of the knee between the upper and lower leg. For runners, this may become critical because a balanced gait is only achieved when this muscle is functioning properly and / or when the foot of the leg is in the air during a run – therefore the popliteus muscle powers the leg towards the next foot strike. Additionally, shortness of the popliteus muscle would lead to an improper foot plant and excess pronation.
- It withdraws the meniscus in the knee to prevent the tissue from becoming trapped in the knee joint.
Injury of the popliteus muscle can also be either from an acute injury or through overuse, as described below:
Acute injuries to the popliteus muscle occur after a significant force to the knee. They are common in road traffic accidents or falls where the knee is extended or over straightened. It might also be injured through impacts that force the knee out to the side. Popliteus injuries may occur in association with other injuries such as posterior crucial ligament tears or ACL ruptures, as well as being part of a posterolateral corner injury involving a number of other structures in the knee.
Overuse injuries to the popliteus muscle develop gradually and are most common for runners. They tend to be due to biomechanical issues and tight hamstring muscles are often to blame.
Causes & Symptoms
Popliteus strain causes pain at the back of the knee in the fold of the leg, that ranges from mild to severe pain. Walking downhill or extensive running will increase the pain. Standing on a slightly bent knee or rotating the knee may also increase the likelihood of a popliteus strain. Some patients may experience a cracking sound from the muscle / tendon when moved or touched. He / she may also feel that his / her injured knee may give way under stress or can lock or catch. Chronic popliteus muscle strain will produce pain first thing in the morning. For runners with a chronic popliteus condition, they will have pain at the beginning of a running course – however, the pain often slowly subsides during the run, as increased heart rate, activity, and blood flow helps reduce inflammation in the popliteus muscle.
Generally, popliteus strain is often caused by:
- Chronic overuse
- Having a muscle strength imbalance in your hamstring muscles may cause the popliteus to weaken
- Having an unstable knee due to a torn ligament, torn meniscus, or arthritis
- Athletes involved in running sports that have not warmed up enough before any running activity
- Poor footwear without correct support can cause the foot and lower leg to over-rotate
- Acute sudden trauma to the popliteus muscle or a strain to the knee may strain or partially tear the popliteus
Who Gets Popliteus Strain?
Anyone with popliteus strain often has pain in the back and outer areas of the knee. There is often pain when straightening the knee fully, or when bending the knee against resistance. Pain is usually worse when walking downhill, including stairs and when running. Popliteus strains most commonly occur in downhill skiers, and in runners and triathletes who compete on hills or uneven surfaces. The typical cause of injury is a direct blow to the inside of the knee or a sudden forceful over straightening of the knee.
How Does It Affect You? How Serious Is It?
Popliteus strains come with three grades of severity, including the following:
- Grade 1 – A Grade 1 popliteus strain means you have slightly pulled your muscles or have very small tears in these muscles. You will usually feel mild cramping which will be a little tender or uncomfortable, although, it will involve little swelling or loss of strength.
- Grade 2 – Grade 2 popliteus strains are more severe and painful than a Grade 1 popliteus strain – this will involve a partial tearing of the fibers in the muscle, tendon, or where the tendon attaches to the bone. You will generally experience pain, along with swelling, decreased range of motion and strength, as well as difficulty walking or running. Your muscles will often be painful when you touch them.
- Grade 3 – This type of grade of popliteus strain involves a complete tear (rupture) of muscle fibers; usually where the muscle meets the tendon or where the tendon attaches to the bone. A Grade 3 popliteus strain is very painful, therefore, you will tend to experience a burning or stabbing pain, a lot of swelling, and significant loss of strength. You will then experience total loss of range of motion in the leg; bruising in the injured area is common and likely. This type of strain will require a surgical repair as there is complete detachment.
In addition, steroid injections can provide temporary relief from the pain of soft tissue-related injuries and are very popular. However, frequent injections should generally be avoided if possible as they can weaken tendons and may lead to a rupture. Complications of this type of injection include:
- Joint infection
- Nerve damage
- Temporary pain & inflammation in the joint
- Tendon weakening or rupture
- Thinning of nearby bone
- Temporary increase in blood sugar
Recommended Treatment & Rehabilitation
A visit to a doctor is the best way for diagnoses any type of knee or leg pain. First off, your doctor will begin with a medical history about you, your current condition, and your symptoms. He / she will ask about the level of your pain, how long you have had your symptoms and the limitations you are experiencing. Details about what and when the issue started, and whether or not you have ever had treatments for this or a smiler condition in the past – these are all very helpful in assessing your injury.
The symptoms of a popliteus strain injury are close to suffering an MCL tear (Medial Collateral Ligament) or meniscus tear. Therefore, your doctor will ask you to perform a muscle test to cause the muscle to contract and look for any weakness and pain in the popliteus area. Diagnostic testing may be ordered to help discover your source of leg pain. MRIs (Magnetic Resonance Imaging) will provide more detailed information and will help to evaluate the soft tissues in and around the area of pain.
In the early stages of healing, after a new popliteus strain injury, treatment often includes rest from aggravating activities, icing the knee for 10-15 minutes every few hours, a compression wrap to help decrease swelling, and anti-inflammatory medications to help decrease pain and inflammation. An assessment of movement patterns and dynamic stability at the feet, ankles, knees, and hips should be performed, to determine factors predisposing the person to injury. As healing progresses, a gentle soft tissue massage of the popliteus muscle and a combination of soft tissue release, contract, relax, stretching techniques, and strengthening exercises to correct imbalances will help to decrease pain and return to activities. Patients should not run or ski until the knee is relieved and should limit sports activities for at least the first 6 weeks of recovery.
Rehabilitation to the popliteus muscle eases knee pain and restores function when this muscle is injured or damaged. The goal of the exercises is, of course, to reduce pain and inflammation. Exercises can also strengthen the muscles around your knee so the popliteus muscle does not bear all of your weight and the burden of walking or running movements. Below are a few exercises you can perform, such as:
Supine hamstring stretch
Lie on your back on the floor or on an exercise mat with both knees bent and your feet planted. Bring your right knee in towards your chest and hold onto the back of your thigh with both hands. Afterwards, lengthen the leg up toward the ceiling as you gently pull the leg towards your head. Hold this position for 30-60 seconds and repeat on the opposite side.
Stand with your feet about hip-distance apart. If you feel unstable, hold onto a wall or back of a chair for balance. Maintain a long spine and lifted chest as you bend gently through your hips and knees. Let the hips bend just about 10 inches as if you are sitting towards a chair. Keep your feet planted, weight in your heels. Finally, pause for 3-5 counts and straighten back up to a stand. Repeat this exercise 10-12 times.
Heel cord stretch
Stand facing a wall. Place your healthy leg forward and bend the knee slightly. Place the injured leg straight behind you with the heel flat and the toes pointed in a little bit. Keep your heels flat on the floor and press your hip complex forward, toward the wall. Lastly, hold for 30 seconds, then repeat this method 2-3 times.
Standing quadriceps stretch
Stand behind the back of a chair and place your hands on it for stability. Then, bend your right knee and pull the heel up toward your right buttock. Grab your ankle with your right hand and pull it closer to your body. Hold for 30-60 seconds, then repeat on the other side.
Sit at the edge of a firm chair with a straight spine. Straighten your right leg and contract the muscles of your thigh as you raise the leg up as high as you can. Hold the lifted leg up for about 5 seconds. Finally, relax the leg and lower back toward the floor.
Stand facing the back of a chair. Hold on for support. Bend your right knee behind you and raise the heel towards the ceiling as far as possible. Hold for 5 seconds, then repeat 10-15 times.
Alternative & Homeopathic Treatment
The fortunate news is that most cases of popliteus strains will heal with simple home treatments within 6 weeks. Some at-home treatments include:
- Rest – This is important for initial healing to reduce pain, swelling, and inflammation in the early stage of your soft tissue injury. Too much rest can also be harmful as joint immobility can actually cause stiffening, overcompensation, and atrophy. This is why rest should be used when reducing initial pain and swelling, but should not be considered for more long-term conservative treatment.
- Cold compression or ice pack – Cold is very effective at reducing pain and inflammation; use at the onset of the injury and during flare-ups.
- Blood circulation boost – After swelling and inflammation have been reduced. You can use your own blood flow to maximize your rehabilitation, maintain healthy blood flow to your muscle, tendons, decrease recovery time, and boost overall long-term healing.
- Avoid activity that causes the injury – While resting the area, it is also important to avoid all activities that may have caused your symptoms, including any repetitive movements.