11.6 Diabetic Foot Care, Skin Integrity & Footwear Assessment
Key Takeaways
- Loss of protective sensation is detected with a 10-gram Semmes-Weinstein monofilament applied at plantar sites; inability to feel it identifies a foot at risk for unnoticed ulceration.
- Patients should inspect their feet daily including between the toes and the soles, using a mirror or a helper when vision or mobility limits direct viewing.
- Moisturizer is applied to the tops and bottoms of the feet but never between the toes, where retained moisture promotes maceration and fungal infection.
- Patients with diabetes should never walk barefoot even indoors, should check inside shoes before putting them on, and should avoid heating pads, hot water bottles, and chemical corn or callus removers.
- An active foot ulcer requires non-weight-bearing exercise modalities, whereas moderate walking is acceptable with loss of protective sensation provided the feet are intact and properly shod.
11.6 Diabetic Foot Care, Skin Integrity & Footwear Assessment
[!NOTE] Blueprint anchor: Domain 6 (Diabetes Management), task 6.12 — Educate patients with diabetes on proper foot care.
Cardiac rehabilitation puts patients with diabetes on treadmills for 36 sessions. In a patient with peripheral neuropathy, an ill-fitting shoe can produce a blister they cannot feel, which becomes an ulcer, which becomes an infection, which becomes an amputation. Foot care is not a side topic bolted onto the diabetes domain — in a program built on walking, it is a direct safety responsibility.
Why the Diabetic Foot Is Vulnerable
Three mechanisms converge:
- Peripheral sensory neuropathy removes the pain signal that normally causes a person to shift position, loosen a shoe, or stop walking. Injury proceeds unnoticed.
- Autonomic neuropathy reduces sweating, producing dry, cracked skin that breaks down and admits bacteria.
- Motor neuropathy and peripheral artery disease produce deformity (claw toes, Charcot changes, altered pressure distribution) and impaired perfusion that prevents healing.
Added to these, hyperglycemia impairs immune function and wound healing, so a minor injury that would resolve in days in another patient can persist and progress.
Screening for Loss of Protective Sensation
| Test | Method | Interpretation |
|---|---|---|
| 10-g Semmes-Weinstein monofilament | Applied perpendicular to plantar sites until it buckles, roughly 1 second, with the patient's eyes closed | Inability to feel it at any tested site indicates loss of protective sensation (LOPS) |
| 128-Hz tuning fork | Vibration sense at the dorsum of the great toe | Reduced or absent vibration sense supports neuropathy |
| Ankle reflexes | Achilles reflex | Diminished or absent with neuropathy |
| Pedal pulses | Dorsalis pedis and posterior tibial | Absent or diminished pulses suggest peripheral artery disease |
| Ankle-brachial index | Ankle SBP ÷ brachial SBP | Below 0.90 indicates PAD; falsely high values above 1.40 occur with medial calcification |
A comprehensive foot examination at least annually is standard for all patients with diabetes, more frequently when LOPS, deformity, PAD, or prior ulceration is present. Any patient with LOPS is in a higher-risk category regardless of how good their feet look today.
The Daily Routine to Teach
Inspection
- Inspect both feet every day, including between the toes and the soles.
- Use a mirror on the floor, a long-handled mirror, or a family member when vision or flexibility prevents direct viewing — this is the specific accommodation for the patient who cannot see their own soles.
- Look for redness, blisters, cuts, cracks, calluses, corns, swelling, warmth, color change, drainage, and ingrown or discolored nails.
Washing and moisturizing
- Wash daily in lukewarm water — test the temperature with the elbow, a thermometer, or another person, because neuropathy impairs temperature sensation and patients scald themselves in water that feels comfortable to an insensate foot.
- Do not soak the feet; prolonged soaking macerates skin.
- Dry thoroughly, especially between the toes.
- Apply moisturizer to the tops and bottoms — never between the toes, where retained moisture promotes maceration and fungal infection.
Nail care
- Cut nails straight across and file the edges; avoid cutting down the sides, which creates ingrown nails.
- Refer to podiatry for nail care when the patient has LOPS, impaired vision, limited reach, thickened nails, or PAD.
Absolute prohibitions
[!WARNING] Teach these as hard rules:
- Never walk barefoot, indoors or outdoors, including to the bathroom at night and on beach or pool decks.
- Never use chemical corn or callus removers — they are acids and cause chemical burns in insensate skin.
- Never perform self-surgery on corns, calluses, or nails with razors or blades.
- Never use heating pads, hot water bottles, electric blankets on the feet, or place feet near a heater or fire — burns occur without warning.
- Never wear new shoes for a long walk; break them in gradually, starting with an hour or two, checking the feet afterward.
Footwear and Socks
| Feature | Recommendation |
|---|---|
| Fit | Measured while standing, late in the day when feet are largest; adequate toe box depth and width |
| Construction | Well-cushioned athletic or walking shoe; closed toe and closed heel; no thongs or sandals with toe posts |
| Pre-use check | Inspect and feel inside the shoe for pebbles, folded liners, or protruding seams before every wear |
| Socks | Seamless, non-binding, moisture-wicking; light-colored socks make drainage visible; change if damp |
| Deformity | Custom-molded or extra-depth shoes with accommodative insoles when deformity or prior ulceration is present |
[!IMPORTANT] Medicare's therapeutic shoe benefit covers one pair of depth-inlay shoes and inserts, or custom-molded shoes and inserts, per calendar year for beneficiaries with diabetes who meet qualifying foot conditions, when certified by the physician managing their diabetes and prescribed and fitted by a qualified supplier. Many patients do not know this exists, and telling them is a concrete, high-value CR intervention.
Exercise Implications
| Foot status | Exercise guidance |
|---|---|
| Intact feet, no LOPS | Standard weight-bearing exercise |
| LOPS, feet intact, properly shod | Moderate walking is acceptable, with proper footwear and daily inspection; avoid high-impact, prolonged running, and step exercise |
| Foot deformity or prior ulceration | Reduced-impact modalities preferred; therapeutic footwear; heightened inspection |
| Active ulcer | Non-weight-bearing modalities only — arm ergometry, seated exercise, aquatic activity is generally avoided with an open wound; coordinate with wound care |
| Any new wound, blister, or redness | Report immediately; do not wait for the next scheduled visit |
[!IMPORTANT] Older teaching held that patients with LOPS should avoid weight-bearing exercise entirely. Current ADA guidance supports moderate walking for patients with LOPS whose feet are intact and appropriately shod, because the cardiovascular and glycemic benefits are substantial and the risk is manageable with proper footwear and daily inspection. The absolute restriction applies to an active ulcer.
In a CR gym: inspect the feet of patients with diabetes and neuropathy periodically rather than assuming, ask about new footwear, and treat any reported blister as urgent rather than trivial.
Realistic Clinical Scenario
Scenario: A 67-year-old man with type 2 diabetes for 18 years enters Phase II. He cannot feel the 10-g monofilament at three of ten plantar sites bilaterally. Dorsalis pedis pulses are diminished. He bought new walking shoes for the program and wore them for the full 30-minute treadmill session on day one. At session three, staff notice he is walking with an altered gait; on inspection there is a 2 cm intact blister with surrounding erythema on the plantar surface of his right great toe. He reports no pain and says he had not looked at his feet.
Analysis: He has documented loss of protective sensation with probable concurrent peripheral artery disease, which is the highest-risk combination — no pain signal to warn him and impaired perfusion to heal him. New shoes worn for a full session without gradual break-in is the precipitant. The absence of pain is expected and is precisely why the lesion progressed unnoticed; the surrounding erythema raises concern for early infection. This is a wound in a neuropathic, likely ischemic foot, not a minor blister.
Plan: Stop weight-bearing exercise today and notify the medical director the same day for urgent evaluation and likely podiatry or wound care referral — do not debride, drain, or apply any over-the-counter product. Convert his prescription to non-weight-bearing modalities such as arm ergometry and seated resistance work until the lesion is cleared. Deliver the full foot care curriculum with teach-back: daily inspection including soles using a floor mirror, lukewarm water tested by elbow, thorough drying and moisturizing but never between the toes, never barefoot, checking inside shoes before wearing, and breaking in new footwear over one to two hours at a time. Inform him about the Medicare therapeutic shoe benefit and refer for evaluation, given his LOPS and diminished pulses. Document the monofilament findings, the wound, the education delivered, and the referrals in the ITP.
A patient with diabetes has loss of protective sensation on monofilament testing but intact skin and well-fitted athletic shoes. What is the current guidance regarding weight-bearing exercise?
Which foot care instruction is correct for a patient with diabetic peripheral neuropathy?
During session three, staff find a 2 cm intact blister with surrounding erythema on the plantar great toe of a patient with loss of protective sensation and diminished pedal pulses. He reports no pain. What is the appropriate response?