How to assess proprioception in a patient with a saphenous (greater saphenous vein) injury?

Testing Proprioception in Saphenous Nerve Injury

The most appropriate method to assess proprioception in a patient with saphenous nerve injury is to test joint position sense by having the patient reproduce specific positions of the ankle and foot, particularly focusing on inversion/eversion movements, while the patient's vision is occluded. 1, 2

Recommended Assessment Methods

Joint Position Reproduction Test

• Have the patient seated with their leg extended and foot unsupported 3
• Occlude the patient's vision (blindfold or ask them to close their eyes) 1
• Passively move the patient's foot to a specific position (e.g., 10-20 degrees of inversion or eversion) 1, 2
• Hold this position for 3-5 seconds to allow the patient to perceive the position 2
• Return the foot to neutral position 1
• Ask the patient to actively reproduce the position 1, 2
• Measure the difference between the target position and the reproduced position 2

Threshold to Detection of Passive Motion

• Position the patient comfortably with the foot supported 1
• Occlude the patient's vision 1, 2
• Move the foot very slowly in a specific direction (inversion/eversion) 1
• Ask the patient to indicate when they first perceive movement 1
• Record the angular displacement at which movement was detected 1, 2

Lower Extremity Position Test

• Have the patient seated with their foot on a smooth surface 3
• Mark specific distances (e.g., 12 cm and 22 cm) on the surface 3
• Move the patient's foot passively along the surface 3
• Ask the patient to verbally indicate when they believe they've reached the target distance 3
• Measure the deviation from the target point as the mismatch score 3

Clinical Considerations

Anatomical Relevance

• The saphenous nerve is a sensory branch of the femoral nerve that provides cutaneous sensation to the medial aspect of the leg and foot 4
• While primarily sensory, saphenous nerve injury can affect proprioceptive feedback from the medial ankle and foot 4
• Patients with saphenous nerve injury may have poor pain proprioception despite having fractures or other injuries 4

Assessment Challenges

• Patients with neurologic compromise or neuropathy may have impaired proprioception that makes standard clinical tests difficult to interpret 4
• In patients with peripheral neuropathy, proprioceptive deficits may be present even without pain or point tenderness 4
• Proprioceptive testing should be compared bilaterally to identify asymmetries 3

Interpretation and Documentation

• Document the specific method used and quantify results when possible 2
• Compare involved versus uninvolved limbs to establish baseline differences 3
• Consider that proprioceptive deficits can occur from traumatic damage to ligaments and muscles, not just nerve injuries 5
• Note that muscle fatigue can adversely affect proprioception testing results 5

Pitfalls to Avoid

• Avoid relying solely on subjective reports; use quantifiable measures when possible 2
• Do not test immediately after exercise, as muscle fatigue can temporarily impair proprioception 5
• Ensure the testing environment is quiet and free from distractions that might affect the patient's concentration 1
• Remember that proprioceptive deficits may be present in patients with diabetic neuropathy even without pain 4
• Avoid using only one testing method; combining multiple assessment techniques provides more comprehensive information 1, 2