Bilateral versus single peripheral nerve impairment and gait speed in community-dwelling older adults

Introduction: Reduced touch sensation indicates Peripheral Nerve Impairment (PNI), and is associated with falls, mobility
disability, and gait impairments in older adults. Whether and to which extent bilateral (BPNI) versus single (SPNI) PNI may
be associated with reduced gait speed is unknown. This study investigates whether subclinical bilateral versus single or no
loss of sensation is associated with reduced gait speed in self-reliant community-dwelling older adults.
Materials and methods: Participants (n=401, age=78.2±5.9 years; 60% women) from Healthy Ageing Network of
Competences (HANC) and SITLESS projects (baseline data) were assessed for tactile sensitivity with 1.4-g monofilament at
the dorsum of the great toe on both feet. PNI was defined as the inability to feel at least 3 touches on either right or left
(single PNI=SPNI) or both feet (bilateral PNI=BPNI). Gait speed was measured over 3-m (usual) and during 2-min maximum
gait test.
Results: Non-impairment (n=142), SPNI (n=100) and BPNI (n=159) groups had 2-min gait speed of 1.21 (0.25), 1.17 (0.22)
and 1.10 (0.27) m/s, respectively, and 3-m usual gait speed of 0.96 (0.22), 0.97 (0.23) and 0.88 (0.24) m/s. BPNI had a
significant and clinically meaningful lower speed compared to non-impairment (0.11m/s, ppdifferences were found between non-impairment and SPNI.
Conclusions: Bilateral subclinical loss of sensation is associated with clinically meaningful lower gait speed to SPNI and may
help identifying people at greater risk of future mobility disability.