Kinematic evaluation and reliability assessment of the Nine Hole Peg Test for manual dexterity.

BACKGROUND: The Nine Hole Peg Test (NHPT) is one of the most frequently used tools to assess manual dexterity. However, no kinematic parameters are provided to describe the quality of the motor performance, since time is the only score. PURPOSE: To investigate test-retest and intra-rater reliability, correlation with clinical test score, and discriminant validity of kinematic indexes during NHPT. STUDY DESIGN: A clinical measurement study. METHODS: Twenty-five healthy right-handed volunteers performed the NHPT. An experienced physiotherapist administered two sessions at a 6-hour interval with two trials for dominant and non-dominant upper limbs. An optoelectronic system was used to detect NHPT performance, which was divided into nine consecutive peg-grasp, peg-transfer, peg-in-hole, hand-return phases, and one final removing phase. Outcome measures were total and single phases times, normalized jerk, mean, peak and time-to-peak of velocity, curvature index during peg-grasp and hand-return phases, and trunk 3D displacement. The statistical analysis included Intraclass Correlation Coefficients (ICCs) for test-retest and intra-rater reliability, Pearson's coefficients for correlation with the NHPT score, and paired t-tests for discriminant validity. RESULTS: Test-retest reliability was excellent for trunk rotation (ICC: 0.91) and good to moderate for the other indexes (ICCs: 0.89-0.61). Intra-rater reliability was excellent for total and removing times (ICCs: 0.91 and 0.94) and good to moderate for the other indexes (ICCs: 0.84-0.66), except for trunk inclination (ICC: 0.37). NHPT phases, normalized jerk, mean velocity, peak of velocity, time-to-peak and curvature index correlated with total time (r-score: 0.8-0.3). NHPT phases and most kinematic indexes discriminated the dominant from non-dominant upper limb, with the greatest effect size for normalized jerk during hand-return (d = 1.16). CONCLUSIONS: Kinematic indexes during NHPT can be considered for manual dexterity assessment. These indexes may allow for the detection of kinematic changes responsible for NHPT score variations in healthy subjects or patients with upper limb impairments.

Smoothness of gait detects early alterations of walking in persons with multiple sclerosis without disability.

In people with Multiple Sclerosis (pwMS) with little or no signs of disability, early detection of walking impairments represents a challenging issue, as simple gait metrics (e.g. speed, cadence, stride length, etc.) may not significantly differ from those of healthy individuals. In this study, we aimed to assess the existence of possible differences in spatial-temporal parameters and smoothness of gait measures (assessed through Harmonic Ratio, HR) obtained from trunk accelerations between 50pwMS without disability (Expanded Disability Status Scale score =1) and 50 age-matched healthy controls. The results show no differences in terms of gait velocity, stride length, stance/swing and double support phases duration, while HR in the direction of motion was significantly lower in pwMS (2.92 vs. 3.67, p<0.001), thus indicating a less smooth gait. The study of trunk accelerations through calculation of HR represents a fast, non-intrusive technique that allows early identification of anomalies in gait patterns of pwMS in absence of disability.

Short-term effects of backpack carriage on plantar pressure and gait in schoolchildren.

PURPOSE: To assess the effects of backpack carriage on plantar pressure distributions and spatio-temporal gait parameters among children. PARTICIPANTS: Two hundred-eighteen schoolchildren, aged 6-13, and attending primary and secondary schools in the city of Cagliari (Italy). METHODS: Participants were tested at school, during regular days. A pressure plate and wearable inertial sensors were used to measure plantar pressures and spatio-temporal parameters of gait. Measures were obtained during both quiet standing and walking, and both with and without a backpack. The latter contained those items a child had on the testing day. RESULTS: Participants carried a mean mass in their backpacks of 5.2 kg, and more than half had a backpack/body mass ratio higher than 15%. While spatio-temporal gait parameters were not affected by backpack carriage, significant increases (up to 25%) in plantar pressures were found during both static standing and walking, especially in the forefoot. CONCLUSION: Under realistic conditions, the impact of backpack carriage was more evident on foot-ground interaction than on gait features. However, long-term consequences of altered plantar pressure need to be assessed in future work, considering the actual durations typically spent carrying school items.