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Published on: February 12, 2018
Validity and reliability of an accelerometer-based assessgame to quantify upper limb selective voluntary motor
Jeffrey W Keller1,2,3, Annina Fahr4,5, Julia Balzer4,5,6
1Swiss Children's Rehab, University Children's Hospital Zurich, Affoltern am Albis, Switzerland. jeffrey.keller@kispi.uzh.ch.
Insights
This study introduces a new game-based method to assess selective voluntary motor control (SVMC) in children with brain lesions. The game shows promise for validity but requires further research to improve reliability for clinical use.
Area of Science:
- Pediatric neurology
- Rehabilitation medicine
- Motor control research
Background:
- Current clinical assessments for selective voluntary motor control (SVMC) use an ordinal scale, limiting precision.
- There is a need for more sensitive and objective methods to evaluate motor function in children with neurological impairments.
Purpose of the Study:
- To introduce and evaluate a novel, playful, interval-scaled method (assessgame) for assessing SVMC in children with brain lesions.
- To determine the validity and reliability of this new assessment tool.
Main Methods:
- Thirty-one neurologically intact children and 33 children with upper motor neuron lesions participated.
- An accelerometer-based movement tracking game (assessgame) measured joint movement accuracy and involuntary movements.
- Outcomes were correlated with established clinical scales (Manual Ability Classification System, Selective Control of the Upper Extremity Scale) and therapist ratings; reliability was assessed using intraclass correlation coefficients.
Main Results:
- The assessgame demonstrated significant correlations with existing clinical measures for both accuracy and involuntary movement scores.
- Patients with brain lesions performed significantly worse than healthy peers across various age levels, except for the dominant/less affected arm in the youngest group.
- The assessment showed good relative and absolute reliability, with intraclass correlation coefficients of 0.80 for accuracy and 0.92 for involuntary movements.
Conclusions:
- The novel assessgame is a valid tool for evaluating SVMC in children with brain lesions.
- While valid, further research is needed to enhance the reliability of the assessgame.
- Future studies should investigate the sensitivity of the assessgame to detect changes following interventions.
Introduction:
Current clinical assessments measure selective voluntary motor control (SVMC) on an ordinal scale. We introduce a playful, interval-scaled method to assess SVMC in children with brain lesions and evaluate its validity and reliability.
Methods:
Thirty-one neurologically intact children (median [1st-3rd quartile]: 11.6 years [8.5-13.9]) and 33 patients (12.2 years [8.8-14.9]) affected by upper motor neuron lesions with mild to moderate impairments participated. Using accelerometers, they played a movement tracking game (assessgame) with isolated joint movements (shoulder, elbow, lower arm [pro-/supination], wrist, and fingers), yielding an accuracy score. Involuntary movements were recorded simultaneously and resulted in an involuntary movement score. Both scores were normalized to the performance of 33 neurologically intact adults (32.5 years [27.9; 38.3]), which represented physiological movement patterns. We correlated the assessgame outcomes with the Manual Ability Classification System, Selective Control of the Upper Extremity Scale, and a therapist rating of involuntary movements. Furthermore, a robust ANCOVA was performed with age as covariate, comparing patients to their healthy peers at the age levels of 7.5, 9, 10.5, 12, and 15 years. Intraclass correlation coefficients and smallest real differences indicated relative and absolute reliability.
Results:
Correlations (Kendall/Spearman) for the accuracy score were τ = 0.29 (p = 0.035; Manual Ability Classification System), ρ = - 0.37 (p = 0.035; Selective Control of the Upper Extremity Scale), and ρ = 0.64 (p < 0.001; therapist rating). Correlations for the involuntary movement metric were τ = 0.37 (p = 0.008), ρ = - 0.55 (p = 0.001), and ρ = 0.79 (p < 0.001), respectively. The robust ANCOVAs revealed that patients performed significantly poorer than their healthy peers in both outcomes and at all age levels except for the dominant/less affected arm, where the youngest age group did not differ significantly. Robust intraclass correlation coefficients and smallest real differences were 0.80 and 1.02 (46% of median patient score) for the accuracy and 0.92 and 2.55 (58%) for involuntary movements, respectively.
Conclusion:
While this novel assessgame is valid, the reliability might need to be improved. Further studies are needed to determine whether the assessgame is sensitive enough to detect changes in SVMC after a surgical or therapeutic intervention.
