Biceps Femoris Muscle
Action – flexion of knee (both long and short head)
extension of hip (long head only)
lateral rotation of knee (tibia) when knee is flexed
Origin – long head: ischial tuberosity
short head: lateral lip of liner aspera
Insertion – head of fibula
Nerve – sciatic nerve (long head – tibial division (L5, S1, S2), short head – common perineal division (S1, S2))
Biceps femoris is one of three hamstring muscles. It is lateral (towards the outside of your thigh) and consists of two heads – a long head and a short head. It can be felt when tensing the hamstrings on the outside of the back the thigh, most easily close to the knee where the tendon is more prominent.
The hamstring group are used when walking, running or lifting from the ground with straight legs. Biceps femoris also plays a large role in providing knee stability.
Injury or dysfunction in the biceps femoris muscle can cause pain or discomfort in the back of the thigh, lower buttock or inner knee regions, and sometimes can be associated with low back pain. Common injuries include hamstring strains/tears, particularly when performing ballistic activity (sprinting, kicking, hurdling) without proper warm-up.
As you can see in the above picture, the pain referral pattern can be higher up into the bottom of the glutes or lower into the back of the knee. Looking at the referral pattern, all hamstrings should be considered when working out the source of an issue.
Symptoms of hamstring muscle tension can feel similar to referred joint pain or disc related pain. Consult your local Myotherapist to help with diagnosis.
Standing upright with feet shoulder width apart, hold a barbell, kettlebell or pair of dumbbells of an appropriate weight with an overhand grip in front of your thighs with straight arms. With knees slightly bent and keeping a straight back, hinge forward at the hips and lower the weights while keeping them close to your legs until about the mid shin level. Pause, then squeeze your glutes to bring the hips forward and return the the starting upright position.
Sitting on the ground with one leg out in front and the other bent out to the side. With your foot on the inside of the straight legs knee. Lean forward (keeping a straight/neutral back) to feel a nice stretch down the back of the straight leg. Rotate legs inwards to favour biceps femoris over the medial hamstrings. You can use a towel to make the stretch stronger.
Sitting on a firm table or chair with your legs hanging off the edge. Place a ball under your right hamstring, where you feel it is tight. Slowly lift your foot, extending your knee a few times. Then move the ball onto the next tender spot along the muscle. Alternatively, not extending the knee, you can use your hands and body weight to push your thigh onto the ball with more pressure. When you feel the discomfort dissipate, move onto the next spot.