Diabetic foot examination frequently appears in OSCEs. You’ll be expected to pick up the relevant clinical signs using your examination skills. This guide provides a clear step-by-step approach to examining diabetic feet, with an included video demonstration.
Wash your hands
Confirm the patient’s details (i.e. name and date of birth)
Explain the examination
Position the patient on an examination couch at 45°
Expose the patient’s lower legs and feet (make sure to also remove any bandages and dressings)
The following pieces of equipment may be required:
- Tuning fork (128 Hz)
- Tendon hammer
Inspect the feet thoroughly (make sure to inspect the heels and between the toes)
The following skin changes may be noted in peripheral vascular disease (PVD):
- Hair loss
- Shiny appearance of the skin
- Erythema – may be suggestive of cellulitis
- Calluses – may suggest abnormal gait or inappropriate footwear
You should inspect for evidence of arterial ulcers, which diabetic patients may have developed secondary to peripheral vascular disease.
The typical features of arterial leg ulcers include the following:
- Very painful
- Deep punched out appearance
- Located at the end of digits or over the lateral surface of the ankle
- Surrounding skin changes associated with PVD (see above)
Venous guttering describes veins that have very little blood within them, hence the “guttered” appearance. This can occur secondary to arterial insufficiency of the lower limbs and therefore may be seen in patients with diabetic foot disease.
Charcot arthropathy involves the progressive degeneration of a weight-bearing joint, a process marked by bony destruction, bone resorption, and eventual deformity due to loss of sensation.
Clinical signs may include:
- Joint deformity
Briefly assess and compare the temperature of the lower limbs and feet:
- Reduced temperature may indicate poor peripheral perfusion
- Consider cellulitis and deep vein thrombosis if you note a hot and tender lower limb
Palpate lower limb pulses, to assess peripheral perfusion:
- Dorsalis pedis artery – lateral to the extensor hallucis longus tendon
- Posterior tibial artery – posterior and inferior to the medial malleolus
- Absence of peripheral pulses is suggestive of peripheral vascular disease.
1. Provide an example of the monofilament sensation on the patient’s arm or sternum.
2. With the patient’s eyes closed, apply the monofilament to each of the following locations in turn:
- The pulp of the hallux
- The pulp of the 3rd digit
- Metatarsophalangeal joints 1, 3 and 5
3. When applying the monofilament to each area:
- Ask the patient to report when they feel the monofilament touch their foot
- Press the monofilament against the skin until it bends slightly (this will ensure only 10g of pressure is applied)
- Hold the monofilament against the skin for 1-2 seconds
- Avoid calluses and scars as they will likely have a reduced level of sensation that is not representative of the surrounding tissue
Observe the patient’s gait, noting the following:
- Is the patent’s gait symmetrical?
- Does the patient appear unsteady when walking?
- Is the patient able to turn effectively?
- Are there any gross gait abnormalities (e.g. broad-based gait, foot drop, antalgic gait)?
Examine the patient’s footwear:
- Note the pattern of wear on the soles (asymmetrical wearing may indicate an abnormal gait)
- Ensure the shoes are the correct size for the patient
- Note holes and materials inside the shoes that could cause foot injury
- Remove and inspect the insoles
Other tests to consider
If abnormalities are identified during the monofilament assessment, consider carrying out the further tests shown below (however these are no longer performed routinely in a diabetic foot assessment).
1. Ask the patient to close their eyes.
2. Tap the 128 Hz tuning fork.
3. Place the tuning fork onto the patient’s sternum and confirm the patient can feel it buzzing.
4. Ask the patient to tell you when they can feel it on their foot and to tell you when it stops buzzing.
5. Assess sensation by placing the vibrating tuning fork onto the distal phalanx of the great toe.
6. If sensation is intact, the patient should state that they can feel the tuning fork buzzing.
7. You should then gently place your hand onto the tuning fork to stop it vibrating. If the patient’s sensation is intact they should be able to recognise when the vibration has stopped.
8. If sensation is impaired, continue to assess more proximally (e.g. proximal phalanx).
9. Repeat the assessment on the other foot.
1. Hold the distal phalanx of the great toe by its sides.
2. Demonstrate movement of the toe upwards and downwards to the patient (whilst they watch).
3. Then ask patient to close their eyes and report if you are moving the toe up or down.
4. If the patient is unable to correctly identify direction of movement, move to a more proximal joint (e.g. ankle > knee > hip).
Ankle jerk reflex
1. Dorsiflex the patient’s foot.
2. Tap the tendon hammer against the Achilles tendon.
3. Observe the calf for contraction (which should occur if the ankle jerk reflex is present).
The ankle jerk reflex may be absent in advanced peripheral neuropathy.
To complete the examination
Thank the patient
Wash your hands
Suggest further assessments, advice and investigations:
- Lower limb neurological examination
- Peripheral vascular examination
- Bedside capillary blood glucose
- Foot care advice
- Calculation of foot risk based on clinical findings
Dr Simon Ashwell