Box and block test, hand grip strength and nine-hole peg test: correlations between three upper limb objective measures in multiple sclerosis.

BACKGROUND AND PURPOSE: Limited data are available in the literature for upper limb impairment in multiple sclerosis (MS). This study aimed to report the distribution of values of hand grip strength (HGS), of the box and block test (BBT) and of the nine-hole peg test (9HPT) correlated with demographic and clinical data in subjects with MS. METHODS: This study involved five Italian neurological centres. The inclusion criteria were age ≥ 18, MS diagnosis, stable disease phase, right-hand dominance. All subjects underwent HGS, BBT and 9-HPT evaluation. RESULTS: In all, 202 subjects with MS were enrolled: 137 females; mean age 48.4 years; mean Expanded Disability Status Scale (EDSS) 4.17; mean disease duration 14.12 years; disease course 129 relapsing-remitting, 21 primary progressive and 52 secondary progressive MS subjects; mean right HGS 25.3 kg, left 23.2 kg; mean right BBT 45.7 blocks, left 44.9 blocks; mean right 9-HPT 30.7 s, left 33.4 s. All results were statistically significantly different compared to healthy controls. HGS, BBT and 9-HPT were associated with age, EDSS and disease duration, whilst disease course correlated with BBT and 9-HPT. The BBT and 9-HPT scores significantly differed according to level of disability (EDSS ≤3.0, 3.5-5.5, ≥6.0). CONCLUSION: Hand grip strength and BBT value distribution in a large MS population is reported. Correlations between HGS, BBT and 9-HPT were generally low.

A comparison of upper limb function in subjects with multiple sclerosis and healthy controls using an inertial measurement unit.

Upper limbs (UL) dysfunction is frequent in people with Multiple Sclerosis (PwMS). Several objective measures of UL function are proposed; however, their use is mostly confined to assess subjects with mild-to-moderate disability and requires fine motor skills, often impaired in high disability level subjects. Thus, a tool to score UL function in the advanced disease stage is lacking. The aim of the study is to analyse and compare UL unilateral and bilateral movements of healthy control (HC) and PwMS, at different disability levels, using an instrumented version (Inertial Measurement Unit, IMU) of the 15-seconds finger-to-nose test (FNT). Each movement cycle was segmented in going/adjusting/returning phases. The inter-hand interval (IHI) allowed assessing bilateral coordination (i.e. synchrony) in each phase. The larger IHI, the more severe the bilateral coordination impairment is. After stratifying PwMS for disability level (PwMSLOW, Expanded Disability Status Scale, EDSS≤5.5 and PwMSHIGH, EDSS≥6), the ANOVA on IHI showed significant differences between PwMS and HC (p<0.001) in all phases. However, only the going phase IHI showed significantly higher asynchrony in PwMSHIGH than PwMSLOW and HC (p<0.001) and no differences between PwMSLOW and HC. The going phase IHI seems to be a clinical marker specific for high disability level PwMS. These findings suggest inertial sensors during FNT could be an easy-to-use method for a more detailed quantitative characterization of UL function in PwMS also in subjects with EDSS greater than 6.

Nine Hole Peg Test asymmetry in refining upper limb assessment in multiple sclerosis.

BACKGROUND: The Expanded Disability Status Scale (EDSS) is the most frequently used scale to measure neurologic impairment and quantify the level of disability in Multiple Sclerosis (MS) even though the scale focuses on ambulation and undervalues upper limb (UL) impairment. The 9-Hole Peg Test (9-HPT) is the gold standard for UL assessment in MS, calculating a mean score from right and left arms, even though subjects with MS often show a lateralization of neurological deficit. OBJECTIVE: The study aimed to determine whether an interaction exists between mean right-left 9-HPT scores or 9HPT score asymmetry (difference between right and left side) in predicting EDSS in MS subjects. METHODS: Demographic and disease variables and 9-HPT scores were obtained from medical records of individuals with MS collected in an ad-hoc database. Subjects with 9-HPT score ≤180 s for each arm were included. An asymmetry score was represented as the absolute value of the difference between 9-HPT scores for both arms. RESULTS: 549 subjects were included: 67.8% female, mean age 45±13.14 years, mean EDSS 3.98±2.12, 356 relapsing-remitting, 68 primary and 125 secondary progressive, mean 9-HPT scores: right arm 30.20 ± 19.99 s, left arm 31.80 ± 20.35 s. Mean asymmetry was 9.35±18.20 s. Correlation between mean right-left 9-HPT scores and EDSS was 0.58 (p<.001). Significant interaction between mean right-left 9-HPT scores and 9-HPT asymmetry in predicting EDSS scores was found. Regression slope of EDSS on mean right-left 9-HPT score decreases as asymmetry value increases (non-significance area values ≥ 40.93 s). CONCLUSIONS: Findings suggest interaction exists between mean right-left 9-HPT scores and asymmetry in predicting EDSS. A consequence of this is that, by disregarding information about asymmetry, studies exploring the association between mean right-left 9-HPT scores and global measures of disability may provide biased results. The bias tends to increase as asymmetry increases, and to be most prevalent among patients with EDSS scores > 6.

Muscular forearm activation in hand-grip tasks with superimposition of mechanical vibrations.

The purpose of this paper is to evaluate the muscular activation of the forearm, with or without vibration stimuli at different frequencies while performing a grip tasks of 45s at various level of exerted force. In 16 individuals, 9 females and 7 males, the surface electromyogram (EMG) of extensor carpi radialis longus and the flexor carpi ulnari muscles were assessed. At a short latency from onset EMG, RMS and the level of MU synchronization were assessed to evaluate the muscular adaptations. Whilst a trend of decay of EMG Median frequency (MDFd) was employed as an index of muscular fatigue. Muscular tasks consists of the grip of an instrumented handle at a force level of 20%, 30%, 40%, 60% of the maximum voluntary force. Vibration was supplied by a shaker to the hand in mono-frequential waves at 20, 30, 33 and 40Hz. In relation to EMG, RMS and MU synchronization, the muscular activation does not seem to change with the superimposition of the mechanical vibrations, on the contrary a lower MDFd was observed at 33Hz than in absence of vibration. This suggests an early muscular fatigue induced by vibration due to the fact that 33Hz is a resonance frequency for the hand-arm system.