Table 2 Baseline data: neurological assessment

Known peripheral neuropathy

N/A

Medical record review.

History of peripheral neuropathy documented in medical records.

Loss of protective sensation

Baily Instruments Ltd® (Salford Quays, UK) Semmes-Weinstein 5.07/10 g monofilament [37].

• Monofilament is first applied to participant’s hand or elbow (so that the participant knows what sensation to expect)

Failure to detect the monofilament at a specific site, even after re-testing the deficit site, in at least one foot will result in a failed test (i.e. score of <3/3 on either foot) [36].

• Ensure the participant’s eyes are closed

• Monofilament applied perpendicular to the skin and held for 1–2 secs, applying sufficient force to bend or buckle the monofilament fibre [16]

• Monofilament applied to the plantar aspects of the hallux, first metatarsophalangeal joint and fifth metatarsophalangeal joint of both feet [36, 43]

• Participant is asked by the assessor to respond “yes” when they feel the monofilament

• This is repeated for all 3 sites on each foot (6 sites in total)

• Deficit sites will be re-tested once

• A monofilament will be not be used on more than 10 participants, without a recovery period of 24 hrs [16, 37, 91]

Vibration perception threshold

Horwell® Neurothesiometer (Wilford, Nottingham, UK).

• Neurothesiometer is first applied to the participant’s hand or elbow (so that the participant knows what sensation to expect)

Vibration perception threshold >25 V in at least one foot will result in a failed test [40–43].

• Participant is asked to close their eyes and to report “yes” when they first start to feel a vibratory sensation

• Neurothesiometer is applied to the apex of the hallux and the voltage is gradually increased until the participant perceives the vibratory sensation [40, 43]

• The minimum reading at which the vibratory sensation is perceived will be recorded (this is repeated 3 times and an average score is recorded for both feet) [40, 43]

Note: Vibration perception threshold will be measured at the base of the first, third or fifth metatarsals if there are current ulcers on the hallux, or previous amputation of the hallux [43].