Differentiation
- The long head and the short head of the biceps femoris are superficial, tube-shaped muscles on the lateral aspect of the posterior thigh.
- The hamstrings are the only muscles on the posterior thigh that will flex the knee ; manual resistance of knee flexion can be used to aid in palpation by stimulating contraction and a sudden increase in tissue density.
- Resisted tibial external rotation can be used to differentiate between the biceps femoris and semimembranosus/semitendinosus .
- The lateral border of the biceps femoris abuts the vastus lateralis . The vastus lateralis is a knee extensor, again knee flexion can be used to differentiate between these two muscles.
Potentially Sensitive Tissues
- The sciatic nerve may be accessible while palpating the medial aspect of the biceps femoris ; however, it is fairly unlikely. If tingling, numbness, or burning is felt, adjust your hand position, attempting to pin trigger points, taut bands, and dense nodules from a different angle.
Trigger Points
- Common trigger points for the long and short head of the biceps femoris are in the middle of the muscle bellies. Note, the middle of the short head of the biceps femoris is roughly halfway between the mid-point of the femur and the knee.
Release Technique
The biceps femoris may be released in two different positions. It is recommended that the technique is practiced with the patient in prone to start; however, experienced practitioners will likely find that the supine position is more effective.
Prone
- Start with the patient in prone, standing on the affected side adjacent to the patient's knee
- Identify the long tube-shaped biceps femoris on the lateral aspect of the posterior thigh.
- Palpation can be confirmed with manual resistance of knee flexion to differentiate between the vastus lateralis on the lateral side, and tibial external rotation to differentiate between semimembranosus/semitendinosus on the medial side.
- Using a thumb over thumb hand position to press into the muscle, and use lateral to medial strokes (perpendicular to the fiber direction) to identify taut bands in this tissue.
- Once a taut band is located, the length of the band is explored for a dense nodule and consistent pressure is applied.
- The practitioner may control the lower leg with the other hand to adjust the amount of knee flexion, adjust the amount of tension in the muscle, and aid in pinning dense nodules.
- Consistent pressure is held until the nodule softens under the practitioner's fingers, or tissue density/sensitivity is significantly reduced (generally 30 - 120 seconds).
Supine
- Start with the patient in supine, standing on the affected side.
- Place the foot or calf of the patient's affected side on your shoulder.
- Use the palpation skills developed in the prone position to identify the long tube-shaped biceps femoris .
- Using a thumb over thumb hand position to press into the muscle, use lateral to medial strokes, perpendicular to the fiber direction, to identify taut bands in this tissue.
- Once a taut band is located, the length of the band is explored for a dense nodule and consistent pressure is applied.
- The practitioner may adjust the amount of tension to aid in pinning dense nodules by leaning into the patient and increasing the amount of hip flexion and knee extension.
- Consistent pressure is held until the nodule softens under the practitioner's fingers, or tissue density/sensitivity is significantly reduced (generally 30 - 120 seconds).
