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Semitendinosus Anatomy: Origin, Insertion, Action, Innervation

Semitendinosus Anatomy Study

Semitendinosus Anatomy Origin: Upper inner quadrant of the posterior surface of the ischial tuberosity, conjoined with the long head of biceps femoris
Insertion: Upper part of the medial surface of the tibia, behind the attachment of the sartorius and distal and slightly anterior to the attachment of the gracilis. Action: Extension of the thigh at the hip, flexion of the leg at the knee, internal rotation of the knee when knee is flexed
Innervation: Tibial portion of the sciatic nerve  (L5, S1 – 2)
Blood Supply: Branches from he internal iliac, popliteal, and profunda femoris arteries.

Synergist:   Gluteus maximus, Adductor magnus, Semimembranosus, Biceps femoris, Gluteus medius, Piriformis

Antagonist: Iliopsoas, Pectineus, Tensor fasciae latae, Adductor brevis, Sartorius

Primary Actions of the Semitendinosus:

1. Extension of the thigh at the hip

    • Agonists: Gluteus maximus, Semitendinosus, Biceps femoris (long head) Adductor magnus (posterior part)
    • Antagonists: Psoas major, Iliacus

2. Flexion of the leg at the knee

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

3. Internal rotation of the leg at the knee

    • Agonists: Semitendinosus, Popliteus
    • Antagonists: Biceps femoris

For information about semitendinosus muscle pain see: Semintendinosus Muscle Pain

Recommended Anatomy Books

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.

Trail Guide To The Body   The Trail Guide To The Body is another excellent book to help you learn the musculature of the human body. Though the book is geared toward massage therapists and physical therapist assistants, the book with its illustrations and text helps anyone gain a thorough understanding of the human musculoskeletal system and movement. I highly recommend this book for anyone studying anatomy and believe that MTs, PTAs, and teachers of body movements should have this book in their possession. I also highly recommend this book for the lay person who wants to gain understanding of the muscle, skeletal system and how our bodies move.  This book will not disappoint!




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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