A presentation discussing the MSK examination and its clinical correlations. The musculoskeletal examination is an important diagnostic tool that healthcare providers use to evaluate and diagnose conditions affecting the bones, joints, and muscles. This type of examination is typically performed during a physical exam and involves assessing the patient's range of motion, muscle strength, and joint stability.
2. Review of Anatomy - Upper Extremity
Brachial Plexus
- Network of nerves
responsible for motor and
sensory innervation of the
upper extremities (shoulders,
arms, and hands)
- Different categories of the
brachial plexus
- Roots, trunks, divisions,
and cords
- E.g. The radial nerve
comes from the
3. Review of Anatomy - Upper Extremity
❏ Triceps - Elbow extension
❏ Biceps - Elbow flexion,
supination
❏ Brachioradialis - only elbow
flexion
❏ Wrist Flexors - wrist flexion
❏ Wrist Extensors - wrist
extension
❏ Hand muscles - abduction,
adduction, and opposition
(thumb only)
4. Review of Anatomy - Lower Extremity
Lumbosacral Plexus
- A group of nerves
responsible for
innervation of parts of
the genital area and
lower extremity
5. Review of Anatomy - Lower Extremity
❏ Illiopsoas - Hip flexion
❏ Gluteus maximus - Hip
extension
❏ Rectus femoris - knee
extension
❏ Biceps femoris - knee flexion
❏ Adductors - Leg adduction
❏ Tibialis anterior - foot
dorsiflexion
❏ Gastrocnemius - foot
plantarflexion
6. Review of Anatomy (cont.)
Myotomes
- Group of muscles
innervated by single spinal
root
7. Review of Anatomy (cont.)
Dermatomes (30 total)
- Specific area of skin innervated by
certain nerve root
Assessment
- Light touch test
- Pinprick test
Pathologies
- Disc herniation
- Reactivated shingles
8. Breaking Down the Motor Examination
Muscle Strength testing
- Can reveal information of neurological
deficits and where the lesion may
occur (e.g. disc herniation)
- Graded out of 5
0/5 No muscle activation
1/5 Trace muscle
activation
2/5 Muscle activation w/o
gravity
3/5 Can hold against
gravity
4/5 Against some
resistance
5/5 Against full resistance
9. Breaking Down the Motor Examination
Upper Extremity Testing
- Arm abduction
- Elbow flexion
- Elbow extension
- Wrist flexion
- Wrist extension
- Finger abduction
- Finger adduction
- Thumb opposition
Lower Extremity Testing
- Hip flexion
- Leg abduction/adduction
- Knee extension
- Knee flexion
- Foot dorsiflexion
- Foot plantarflexion
11. Clinical Example (cont.)
Botulinum toxin injection for spastic
patients
- Weakens the muscle activation for
~ 2 months
- If a spastic patient presents with
pronation of the forearm - many
physicians perform a brachialis
botox injection as opposed to the
biceps as the biceps helps with
supination!!!
Here we have the brachial plexus. This is the network of nerves that are responsible for both sensory and motor nerve. When trying to localize a lesion in the neuro/musculoskeletal exam, it’s important to understand the differences between a lesion at the ROOT and a lesion of the NERVE itself (e.g. median nerve lesion presents differently than a C8 lesion - even though the median nerve is derived from part of the C8)
This is a heavy slide, but the most important things is that on the humeral part of the upper extremity, you have the biceps brachii, the triceps, the coracobrachialis, and part of the brachioradialis.
Then on the forearm, you have the wrist extensors and the wrist flexors.
This is another heavy anatomy slide but the most important things to take out of it is the main muscles involved in the movements of the lower extremity. Every muscle was not included, such as the sartorius being involved in knee extension. When testing the lower extremity on the motor examination - keep in mind what muscles you are testing and what nerves are innervating it.
Myotomes are similar to dermatomes but instead for muscle innervation of the nerve roots
You have 8 cervical, 12 thoracic, 5 lumbar, and 5 sacral dermatomes.
Common pathologies relating to dermatomes
Disc herniation: numbness and tingling to site
Shingles: Herpes zoster virus hides in the ganglion of the nerve root and reactivates in a dermatomal pattern
When testing muscle strength, it can be difficult at first to get a hold of what is 5/5 and what is ⅘. The table lists some standards for muscle strength testing. With more practice, you will be able to tell the difference on physical examination.
It’s important to stabilize the proximal joint when testing the muscles so that you isolate the area (e.g. stabilize elbow when testing wrist extensors and flexors).
Patients with spasticity (cerebral palsy, post-stroke, etc.) have different presentations, but this is a common example of how they may present.
The main thing about understanding anatomy for botox injections for spasticity is understanding the actions of the muscles. Remember that the typical presentation if a flexed elbow and pronated forearm. If you inject at the biceps brachii (which is involved in supination), you may get worsening pronation. Therefore, an alternative is the brachialis muscle which is solely an elbow flexor.
