The effects of hand training in patients with Welander distal myopathy and myotonic dystrophy type 1

Abstract: The overall aim was to study and gain knowledge about the effects of hand training on both functional capacity such as hand function and Activities of Daily Living (ADL) in patients with Welander distal myopathy (WDM) and Myotonic dystrophy type 1 (DM1). The thesis comprises three interventional studies regarding the effects of hand training in patients with WDM (Study I) and DM1 (Studies II & IV), and one reliability study (Study III) including test-retest and inter-rater reliability of four hand function testing instruments used in Study IV. Study IV was a single-blinded longitudinal randomised control trial (RCT) with a crossover design, i.e. a follow-up on the criterion-related single-case study with five DM1 patients (Study II). Functional data were collected by using different hand function testing instruments including the Grippit® (Studies I-IV), Grip Ability Test (GAT) (Studies III-IV), hand-held Myometer (Microfet2™) (Studies II-IV), Purdue Pegboard (Studies II-IV), Manual Muscle Testing (MMT; 0-5 scale) (Study I) and finger goniometer (Study I). Self-rated myotonia using a VAS scale was added as an outcome measure in Study II. ADL were evaluated using the areas of the ADL taxonomy in a structured verbal interview (Study I), and the Canadian Model of Occupational Performance (COPM) (Studies II and IV). Assessment of Motor and Process Skills (AMPS) was evaluated in Study IV. Life satisfaction was evaluated using a modified version of the Life Satisfaction Checklist (LiSat9) in Study I. Fourteen WDM patients were included in Study I, five DM1 patients were included in Study II, 16 WDM patients and DM1 patients, respectively, participated in Study III and 35 DM1 patients were enrolled in Study IV. The reliability study (Study III) showed mainly good–very good (intra-class correlation coefficient 0.61) intrarater (test-retest) and inter-rater reliability in three out of four instruments, specifically the Grippit®, the handheld Myometer (Microfet2™) and the Purdue Pegboard. The three interventional studies (Studies I-II & IV) all included a period of three months of hand training with resistance putties, both guided and self-training. The results of the these studies show that hand training in WDM and DM1 patients is safe, with minor but significant improvements in hand function.