5.7 Structural Foot, Gait, Footwear, Insole, and Sock Examination

Structural Examination

Begin with the patient seated and both feet exposed. Compare length, width, arch shape, hindfoot alignment, forefoot position, toe posture, muscle bulk, and scars. Inspect for pes cavus, planus, hallux valgus, hallux limitus or rigidus, claw toes, hammer toes, prominent metatarsal heads, tailor’s bunion, limited fat padding, equinus, partial amputation, and rocker-bottom change. Describe a deformity and its pressure consequence rather than simply checking a box.

Palpate bony prominences and correlate them with callus, hemorrhage, erythema, blister, or ulcer. A plantar callus under the second metatarsal head in a foot with toe clawing supports a pressure mechanism. A distal toe lesion may result from a flexed digit, while a dorsal proximal-interphalangeal lesion suggests shoe contact. Prior ray or toe amputation can shift load to neighboring structures.

Inspect for Charcot features: unilateral warmth, edema, redness, collapse, instability, or a changed arch in a person with neuropathy. Active Charcot neuro-osteoarthropathy is a clinicoradiologic diagnosis; temperature asymmetry supports inflammation but has no single validated diagnostic cutoff. Prompt knee-high immobilization or offloading while diagnostic studies proceed helps limit additional injury. Normal initial radiographs do not exclude early disease, and MRI is considered when suspicion remains and plain films are normal.

Motion and Strength

Assess ankle dorsiflexion with the knee flexed and extended when feasible to distinguish gastrocnemius from combined gastrocnemius-soleus limitation. Evaluate subtalar motion, first metatarsophalangeal dorsiflexion, and flexible versus rigid toe deformity. Avoid forcing an acutely inflamed or unstable joint. Limited ankle or hallux motion can interrupt normal roll-over and concentrate plantar pressure.

Test gross dorsiflexion, plantar flexion, inversion, eversion, and toe flexion and extension against appropriate resistance. Observe asymmetry and substitution. Intrinsic weakness may contribute to toe deformity, but apparent weakness can also reflect pain, prior surgery, neurologic disease, or poor comprehension. Record what the patient did and the testing position.

Standing and Gait

If safe, observe standing alignment, base of support, balance, and weight shift. During gait, note step length, cadence, foot progression, heel contact, midstance, timing of heel rise, push-off, toe clearance, antalgia, and use of an assistive device. Inspective gait assessment does not quantify plantar pressure, but it identifies reasons for further testing. A Harris mat or ink footprint shows contact pattern; an instrumented pressure platform or in-shoe sensor provides regional magnitude and timing. There is no universal pressure value that guarantees ulceration, because tissue damage also depends on repetition, duration, shear, tissue tolerance, and footwear.

Footwear Examination

Examine the shoes the patient actually wears, including work shoes and indoor footwear. Identify style, age, closure, heel height, outsole stability, and wear. Check fit while the patient is standing when appropriate: length, width, depth, toe clearance, heel slippage, and pressure over deformities. A removable insole is taken out and inspected for compression, cracks, ridges, contamination, or an impression showing concentrated load. Run a hand carefully inside the shoe for seams, rough edges, or a foreign body. Compare outsole wear with gait findings.

A worn shoe may be protective in one area and dangerous in another. A deep shoe is not therapeutic if the insole is bottomed out or a claw toe strikes the upper. Conversely, an expensive custom shoe provides no protection when left in the closet. Ask when and where the person wears each shoe and whether redness appears after use. For a healed plantar ulcer, current prevention guidance favors therapeutic footwear with a demonstrated pressure-relieving effect and consistent indoor and outdoor use.

Inspect socks for size, constrictive bands, bulky seams, holes, dampness, wrinkles, and staining. Light-colored socks can make drainage visible, but material choice should prioritize fit and moisture control. Compression garments require an appropriate vascular assessment and prescription.

Synthesis

End with a mechanical diagnosis stated in plain language: for example, “rigid second-toe clawing plus shallow toe box creates dorsal pressure, with a matching erythematous mark and upper-shoe wear.” That statement directly supports shoe modification, orthosis, offloading, callus care, or surgical referral. Reassess after intervention; fit and pressure change over time as edema, deformity, activity, and materials change.

Reassessment After Modification

After adding an insole, rocker, pad, or device, repeat the skin and gait check rather than assuming success. Look immediately for new edge pressure, instability, toe contact, heel slippage, and altered loading on the opposite limb. At follow-up, compare callus, redness, wear marks, activity, and—when available—in-shoe pressure. A modification that unloads one site but creates a transfer lesion elsewhere is not a successful intervention.

Mechanical Correlation Table