A myotome refers to a group of muscles innervated by a single spinal root, crucial for coordinating voluntary muscle movement and assessing nerve root compression. Assessment involves testing muscle strength through isometric contractions across various spinal levels for both upper and lower limbs. Key myotome functions include neck flexion, shoulder elevation, elbow movements, and lower limb flexions and extensions.

1. MYOTOME
RATHNA PANDI V
M.P.T(ORTHOPEDICS) 1ST YEAR
SCHOOL OF PHYSIOTHERAPY
Vels institute of science and technology in
advanced studies

2. MYOTOME
• A myotome refers to a group of muscles innervated by the nerves of
single spinal root .
• It is responsible for the co ordination of voluntary muscle movement.

3. MYOTOME-purpose
• Muscle strength in a particular myotome may help to identify the
nerve root compression

4. Myotome -assessment
• Myotome is tested with an isometric contraction of the muscle by an
resistance with the hold time of 5 seconds

5. Myotome upper limb
• C1-C2 –Neck flexion
• C3- Neck side flexion
• C4-shoulder elevation
• C5- shoulder abduction
• C6– Elbow flexion and Wrist extension
• C7 – Elbow extension and wrist flexion
• C8 – Thumb extension and ulnar deviation
• T1 – Finger abduction

6. C1-C2 NECK FLEXION C3 NECK SIDE FLEXION

7. •
C4 SHOULDER ELEVATION C5 SHOULDER ABDUCTION C6 ELBOW FLEXION

8. • D
C6 WRIST EXTENSION C7 ELBOW EXTENSION C7 WRIST FLEXION

9. C8 THUMB EXTENSION
T1 FINGER ABDUCTION

10. Myotome lower limb
• L1-L2 – Hip flexion
• L3 – Knee extension
• L4 – Ankle dorsiflexion
• L5 – Great toe extension
• S1 – Ankle plantar flexion and ankle eversion
• S2-Hip extension and knee flexion
• S3-Knee flexion

11. •
L1-L2 HIP FLEXION L3 KNEE EXTENSION

12. •
L4 ANKLE DORSI FLEXION S1 ANKLE EVERSION

13. L5 BIG TOE EXTENSION

14. •
S1 HIP EXTENSION
S1-S2 KNEE FLEXION

15. UPPER LIMB MYOTOME

16. LOWER LIMB MYOTOME

17. source
• Books
Magee, David J. Orthopedic Physical Assessment. Philadelphia :Saunders, 2002.