Biceps Femoris Anatomy: Origin, Insertion, Action, Innervation

Biceps Femoris Anatomy Study

Biceps Femoris Anatomy
Long head of Biceps Femoris: 

Origin: Upper and inner surface of the posterior side of the ischial tuberosity, conjoined with semitendinosus
Insertion: The main attachment is to the styloid process of the fibula, forming a semicircle around the lateral collateral ligament. The remainder splits into three laminae: the intermediate lamina fuses with the lateral fibular collateral ligament, the others pass superficial and deep to the ligament to  attach to the lateral condyle of the tibia.
Action:  Flexes knee joint, laterally rotates knee joint, extends hip joint
Innervation: Tibial portion of the sciatic nerve (L5,S1)
Blood Supply: Branches from the internal iliac, popliteal and profunda femoris arteries.

Synergist:

Prime Movers: Gluteus maximus, Adductor magnus (posterior part).
Accessory Movers: Semimembranosus, Semitendinosus,  Piriformis.

Primary Actions of the Long Head of the Biceps Femoris:

1. Flexion of the leg at the knee

  • Agonist: Semitendinosus, Semimembranosus
  • Antagonists: Vastus Lateralis, Vastus Medialis, Vastus Intermedius, Rectus Femoris

2. External rotation of the  knee

  • Agonists: Biceps Femoris (short head)
  • Antagonists: Popliteus, Semitendinosus, Semimembranosus

3. Extension of the thigh at the hip

  • Agonists: Gluteus maximus, Semitendinosus, Semimembranosus, Adductor Magnus (posterior fibers)
  • Antagonists: Psoas Major, Iliacus

 

Short Head of Biceps Femoris:

Origin: Middle third of the linea aspera, lateral to the supracondylar ridge of the femur.
Insertion:  Joining with the long head in the distal thigh, it attaches to the styloid process of the fibular head forming a semicircle around the lateral fibular collateral ligament. Remaining  splits into three laminae. The intermediate lamina fuses with the fibular collateral ligament while the other two pass superficial and deep to the ligament to attach to the lateral condyle of the tibia.
Action:  Flexes knee joint, laterally rotates knee joint
Innervation: Common peroneal portion of the sciatic nerve (L5, S1)
Blood Supply: Branches from the internal iliac, popliteal and profunda femoris artery.

Primary Actions of the Short Head of the Biceps Femoris:

1. Flexion of the leg at the knee

  • Agonist: Semitendinosus, Semimembranosus
  • Antagonists: Vastus Lateralis, Vastus Medialis, Vastus Intermedius, Rectus Femoris

2. External rotation of the  knee

  • Agonists: Biceps Femoris (short head)
  • Antagonists: Popliteus, Semitendinosus, Semimembranosus

3. Extension of the thigh at the hip

  • Agonists: Gluteus maximus, Semitendinosus, Semimembranosus, Adductor Magnus (posterior fibers)
  • Antagonists: Psoas Major, Iliacus

For pain pattern information see: Biceps Femoris Knee and Thigh Pain


Anatomy Study Aids

Musculoskeletal Anatomy Flashcards

Musculoskeletal Flashcards

Are you a student or professional therapist who needs to brush up on the musculoskeletal system? Dr. Joseph E. Muscolino DC has developed a comprehensive set of flashcards that will help develop a mind’s picture of exactly where the muscles lie under the skin. A highly recommended study aid!


coloring_book
The Anatomy Coloring Book is one of the best study and reference books for beginning anatomy students. The diagrams are clearly labeled and allow you to see the relationship and placement of the various structures of the body. You will also be surprised how the act of coloring will help with recall. But this is not just a beginners book, it is also great for practitioners and therapists to have on hand to use with clients and patients to use as a visual reference.
basic_clinical_massa


Out of the scores of books in my office Basic Clinical Massage Therapy is by far the most referenced book in my library. The musculoskeletal system is overlaid on human models allowing you to learn the precise location, origin and insertions of each muscle. The models are pictured in various poses throughout the book which also helps you visualize muscles in motion and their actions relationship with the skeletal structure and other muscles. Though it is written for massage therapists, it is an excellent book for anyone who wants to learn about the muscular system. MT’s will benefit from recommended treatments for each muscle.

 

 

 

References:

The Trigger Point Therapy Workbook – Claire Davies, Amber Davies, and David G. Simons

Basic Clinical Massage Therapy: Integrating Anatomy and Treatment – James H. Clay and David M. Pounds

Trigger Point Therapy for Myofascial Pain – Donna Finando and Steven Finando

Massage Therapy Principles and Practice – Susan Salvo

Theory & Practice of Therapeutic Massage – Mark Beck

 

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