Hamstring Muscles (1).pptx

This presentation can be used for MBBS Anatomy Seminar on the topic of Hamstring Muscles.

1. Hamst ring Muscles -Rishabh Dudeja

2. Contents Introduction to Hamstring Muscles Features Actions Various Hamstring Muscles a . Semitendinosus b . Biceps Femoris c . Semimembranosus d. Ischial head of the Adductor Magnus Clinical Significance of Hamstring Muscles

3. What are the Hamstring Muscles? The muscles on the back of the thigh are called the Hamstring Muscles. The hamstring muscles are: 1. Semitendinosus 2. Semimembranosus 3. Biceps femoris (long head) 4. Ischial head of adductor magnus

4. Features of Hamstring Muscles: The characteristic features of hamstring muscles are: 1. All arise from the ischial tuberosity. 2. All are inserted into one of the bones of the leg. 3. All are supplied by tibial part of the sciatic nerve. 4. All are flexors of the knee and extensors of the hip joint.

5. Nerve supply: Tibial part of sciatic nerve (L5,S1,S2) Blood supply: from the perforating branches of the deep femoral artery, also known as the profunda femoris artery. The profunda femoris is a branch of the femoral artery.

6. Actions: Chief flexors of the knee Medial rotator of the leg in semi flexed knee Weak extensors of the hip.

7. Source: Textbook of Anatomy by Vishram Singh

8. So Source: Textbook of Anatomy by Vishram Singh Semitendinosus And Biceps Femoris

9. Semitendinosus Lies Superficial to the semimembranosus. Origin: It arises along with the long head of biceps femoris from lower medial part of the upper quadrilateral area of the ischial tuberosity. Insertion: into the upper part of the medial surfaces of the tibia behind the insertion of sartorius and gracilis muscles Source: BD Chaurasia’s Human Anatomy

10. Biceps Femoris It has two heads of origin - 1. Long head, arises from lower medial part of the upper quadrilateral area of the ischial tuberosity in common with the semitendinosus and also from the lower part of the sacrotuberous ligament. 2. Short head, arises from the lower part of the lateral lip of the linea aspera and upper two-third of the lateral supracondylar line.

11. Insertion of Biceps Femoris The two heads unite in the lower third of the thigh to form a conjoint tendon, which slopes downward and laterally to be inserted on to the head of fibula in front of the styloid process.

12. Nerve supply of Biceps Femoris: 1. Long head, by the tibial part of the sciatic nerve. 2. Short head, by the common peroneal part of the sciatic nerve. Actions: Chief flexors of the knee Medial rotator of the leg in semi flexed knee Weak extensors of the hip.

13. Semimembranosus Lies deep to semitendinosus. NOTE: expansions from the tendon form the oblique popliteal ligament and the fascia covering the popliteus.

14. Ischial Head of the Adductor Magnus Origin: It arises from the inferolateral part of the ischial tuberosity. Insertion: It descends almost vertically downward to be inserted on the adductor tubercle.

15. Dissectional view of Hamstring Muscles Source: Anatomical Society, HIMS

16. Clinical Significance of Hamstring Muscles • If hamstring muscles are paralyzed, the patient tends to fall forward because the gluteus maximus muscle cannot maintain the necessary tone to stand upright. • In ancient warfare, the hamstring tendons of soldiers were cut so that they could not run. This was termed “hamstringing” the enemy.

17. Source: BD Chaurasia’s Human Anatomy Testing the hamstring muscles: Hamstring muscles can be tested by requesting the patient to flex the knee against resistance in prone position.

18. Source: BD Chaurasia’s Human Anatomy The inflammation of semimembranosus bursa is called semimembranosus bursitis. The bursa becomes more prominent during extension of knee, and disappears during flexion of knee.

19. Source: The Times of India

20. Take Away Points Conventionally, the short head of Biceps Femoris is not included in the hamstring group (as it originates from lateral lip of the linea aspera and not from the ischial tuberosity). Adductor Magnus is included amongst the Hamstrings groups of muscles despite reaching only up to the Adductor Tubercle of the femur and not inserting into leg bone (Tibia).

21. Why is the Adductor Magnus included in Hamstrings group? The Adductor Magnus is included in Hamstrings group of muscles b ecause the tibial collateral ligament of the knee joint morphologically represents the degenerated tendon of this muscle, which is attached below on the tibia.

22. SUMMARY