Tendon reflex

Tendon reflex (or T-reflex) may refer to:

• A stretch reflex, when the stretch is created by a blow upon a muscle tendon. This is the usual definition of the term. ^[1][2] A common example is the standard knee-jerk response when visiting the doctor. ^[3] Deep tendon reflex also usually refers to this sense. A deep tendon reflex is often associated with muscle stretching. ^[4] Tendon reflex tests are used to determine the integrity of the spinal cord and peripheral nervous system, and they can be used to detect the presence of a neuromuscular disease. ^[5]
• The Golgi tendon reflex, motivated by that the sensory receptors for this reflex are anatomically located in the tendon, while the sensory receptors for the stretch reflex are actually inside the proper muscle.

Testing

To test the reflex, tap on the tendon. In a healthy individual the intensity on both sides is equal. This means that the connections between the spinal cord and the muscles are undamaged.^[6]

Main Spinal Nerve Roots Involved:

• Biceps (C5, C6)
• Brachioradialis (C6)
• Triceps (C7)
• Patellar (L4)
• Achilles Tendon (S1)

Functions of Golgi Tendon Reflex

The Golgi tendon reflex is a response to extensive tension on a tendon.^[7] It helps avoid strong muscle contractions which could tear the tendon from either the muscle or bone.^[7] In sports, quick movements can damage the tendon before the reflex can occur.^[7] The tendon reflex also helps spread the workload more evenly over the entire muscle by preventing “muscle fibers connected with overstimulated tendon organs so that their contraction is more comparable to the contraction of the rest of the muscle.”^[7]

References

1. TheFreeDictionary > tendon reflex Citing: Dorland's Medical Dictionary for Health Consumers. 2007
2. dictionary.com > tendon reflex Citing: Merriam-Webster's Medical Dictionary, 2007 and The American Heritage Stedman's Medical Dictionary 2002
3. wustl.edu > tendon reflex Citing: wustl.edu. REFLEXES: Tendon & Other. 2008.
4. TheFreeDictionary.com > deep tendon reflex Citing: The American Heritage Medical Dictionary, 2007 and Mosby's Medical Dictionary, 8th edition, 2009
5. eNotes > tendon reflex Citing: Encyclopedia of Nursing and Allied Health. 2002
6. Batavia, Mitchell; McDonough, Andrew L. (2000). "Demonstrating the Stretch Reflex: A Mechanical Model". The American Biology Teacher 62 (7): 503–7. doi:10.1662/0002-7685(2000)062[0503:DTSRAM]2.0.CO;2. JSTOR 4450958.
7. Saladin, Kenneth S. Anatomy & Physiology: the Unity of Form and Function. Dubuque: McGraw-Hill, 2012. Print.

External links

• "Tendon reflex" at Dorland's Medical Dictionary

• Reflex, Tendon at the US National Library of Medicine Medical Subject Headings (MeSH)
• Kenneth Walker, H (1990). "Deep Tendon Reflexes". In Kenneth Walker, H; Dallas Hall, W; Willis Hurst, J. Clinical Methods: The History, Physical, and Laboratory Examinations (3rd ed.). Boston: Butterworths. ISBN 0-409-90077-X. PMID 21250237.