An Engineered Glove for the Objective Assessment of Hand Dexterity in Patients With Systemic Sclerosis

Hand disability is a major musculoskeletal functional impairment in systemic sclerosis (SSc), but its objective assessment remains challenging. The validated Hand Test System (HTS) engineered glove has provided quantitative dexterity data in rheumatic diseases. The primary objective was to evaluate the applicability of the HTS glove in patients with SSc by comparing its parameters (touch duration [TD], intertapping interval [ITI], and movement rate [MR]) with healthy controls (HCs). The assumptions were that HTS parameters would be significantly impaired in patients with SSc and would correlate with clinical, imaging, and patient-reported outcome measures (PROMs).

A cross-sectional study was conducted enrolling 25 patients with SSc (fulfilling 2013 American College of Rheumatology/EULAR criteria) and 25 matched HCs. The main outcome variables were the HTS glove parameters. All participants also underwent grip strength measurement and an assessment of PROMs (Scleroderma Health Assessment Questionnaire and Duruöz Hand Index), together with a performance-based evaluation of hand mobility using the Hand Mobility in Scleroderma test. Clinical and imaging data were collected for patients with SSc including the modified Rodnan skin score (mRSS) and high-frequency skin ultrasonography (HFSU) to measure hand and total body dermal thickness.

Patients with SSc performed finger movements significantly more slowly and less efficiently than HCs, demonstrated by prolonged mean TD and ITI and reduced MR (P < 0.05 for all). In patients with SSc, HTS parameters significantly correlated with poorer PROMs (0.39 < r < 0.65, all P < 0.01 for all). Notably, both mean TD and ITI directly correlated with the mRSS (0.40 < r < 0.48, all P < 0.05). Furthermore, the mean TD showed a significant direct correlation with HFSU-measured dermal thickness of the dorsum of the hands and with total body dermal thickness (P < 0.05 for all). No significant differences in HTS parameters were detected based on nailfold videocapillaroscopy findings or organ involvement.

The HTS glove provides objective measures of the impaired hand dexterity in SSc. The significant correlations between HTS parameters, PROMs, mRSS, and HFSU-measured dermal thickness suggest a significant relationship between skin fibrosis and functional hand disability. The HTS glove seems a promising tool for objectively monitoring SSc hand outcomes, and studies to explore its utility in monitoring therapeutic responses are in progression.