Determining skill level in myoelectric prosthesis use with multiple outcome measures (original) (raw)
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Assessment of Capacity for Myoelectric Control: a new rasch-built measure of prosthetic hand control
Journal of Rehabilitation Medicine, 2004
Objective: To report the results from a Rasch rating scale analysis of the Assessment of Capacity for Myoelectric Control (ACMC) implemented to evaluate internal scale validity, person response validity, separation reliability, targeting and responsiveness of the measures over time. Design: Longitudinal data (18 months) from a prospective study of development of capacity for myoelectric control in children and adults were used for the analysis. Patients: A consecutive sample of 75 subjects (43 males, 32 females) with upper limb reduction de®ciency or amputation and myoelectric prosthetic hands referred for occupational therapy from September 2000 to March 2002. Participants' ages ranged from 2 to 57 years. Methods: Outcome measure was the ACMC. Occupational therapists completed 210 assessments at an arm prosthesis centre in Sweden. A two-faceted rating scale analysis of the data was performed. Results: All 30 ACMC items and 96.2% of participants demonstrated goodness-of-®t to the rating scale model for the ACMC. Separation and SE values suggested adequate reliability of the item and person estimates. Conclusion: The items demonstrated internal scale validity and the participants demonstrated person response validity. The ACMC was well targeted and sensitive enough to detect expected change in ability.
Journal of Prosthetics and Orthotics, 2023
Introduction: Research with multiarticulating prosthetic hands on patient-reported ease of activities of daily living (ADLs) and usefulness is still limited. This study aimed at comparing ease of ADL performance and usefulness of two common multiarticulating prosthetic hands. Methods: Twenty subjects with transradial amputation wearing the bebionic (n = 10) or i-Limb (n = 10) hands were assessed with a hybrid Orthotics and Prosthetics User Survey-Upper Extremity Functional Status (OPUS-UEFS)/Prosthetic Upper Extremity Functional Index (PUFI) outcome measure previously used in a study with another multigrip prosthetic hand. Results: There were no significant differences between the bebionic and i-Limb hands. However, the analysis of individual activities revealed that each multiarticulating hand had specific strengths and weaknesses compared with a historic control group with conventional myoelectric hands. Discussion: Both multiarticulating hands may improve ease of performing ADLs compared with conventional myoelectric hands. However, more grip types available do not necessarily result in greater ease or usefulness compared with advanced hands with fewer grip types. Conclusions: Clinicians must match the patients' functional needs with the differential functional profiles of the available multiarticulating hands. Clinical Relevance: The present study is the first to provide comparative patient-reported outcomes on 3 multigrip prosthetic hands as well as standard myoelectric hands in 23 common ADLs. The distinct patient-reported ease and usefulness profiles of the different hands may inform and support clinicians' decision-making on hand selection for individual patients with transradial amputation.
Skill assessment in upper limb myoelectric prosthesis
2018
Upper limb myoelectric prostheses remain challenging to use and are often abandoned. A proficient user must be able to plan/execute arm movements while activating the residual muscle(s), accounting for delays and unpredictability in prosthesis response. There is no validated, low cost measure of skill in performing such actions. Trial-trial variability of joint angle trajectories measured during functional task performance, linearly normalised by time, shows promise. However, linear normalisation of time introduces errors, and expensive camera systems are required for joint angle measurements. This study investigated whether trial-trial variability, assessed using dynamic time warping (DTW) of limb segment acceleration measured during functional task performance, is a valid measure of user skill. Temporal and amplitude variability of forearm accelerations were determined in 1) seven myoelectric prosthesis users and six anatomically-intact controls and 2) seven anatomically-intact subjects learning to use a prosthesis simulator over repeated sessions. 1: temporal variability showed clear group differences (p<0.05). 2: temporal variability considerably increased on first use of a prosthesis simulator, then declined with training (both p<0.05). Amplitude variability showed less obvious differences. Analysing forearm accelerations using DTW appears to be a valid low-cost method for quantifying movement quality of upper limb prosthesis use during goal-oriented task performance.
Changes in performance over time while learning to use a myoelectric prosthesis
Background: Training increases the functional use of an upper limb prosthesis, but little is known about how people learn to use their prosthesis. The aim of this study was to describe the changes in performance with an upper limb myoelectric prosthesis during practice. The results provide a basis to develop an evidence-based training program. Methods: Thirty-one able-bodied participants took part in an experiment as well as thirty-one age-and gender-matched controls. Participants in the experimental condition, randomly assigned to one of four groups, practiced with a myoelectric simulator for five sessions in a two-weeks period. Group 1 practiced direct grasping, Group 2 practiced indirect grasping, Group 3 practiced fixating, and Group 4 practiced a combination of all three tasks. The Southampton Hand Assessment Procedure (SHAP) was assessed in a pretest, posttest, and two retention tests. Participants in the control condition performed SHAP two times, two weeks apart with no practice in between. Compressible objects were used in the grasping tasks. Changes in end-point kinematics, joint angles, and grip force control, the latter measured by magnitude of object compression, were examined. Results: The experimental groups improved more on SHAP than the control group. Interestingly, the fixation group improved comparable to the other training groups on the SHAP. Improvement in global position of the prosthesis leveled off after three practice sessions, whereas learning to control grip force required more time. The indirect grasping group had the smallest object compression in the beginning and this did not change over time, whereas the direct grasping and the combination group had a decrease in compression over time. Moreover, the indirect grasping group had the smallest grasping time that did not vary over object rigidity, while for the other two groups the grasping time decreased with an increase in object rigidity.
Instrumented objects for quantitative evaluation of hand grasp
Journal of rehabilitation research and development, 1997
Two instrumented objects have been developed for quantitative assessment of functional tasks performed with the hand. These objects are useful for assessing neuroprosthetic hand grasp systems, and may also be useful in evaluating a variety of other upper limb disabilities and rehabilitation techniques. One object monitors grasp forced and object orientation during palmar prehension, allowing simulation of a drinking task or of manipulating a book. The second object monitors grasp force during lateral prehension for simulating eating or writing tasks. The two objects provide tools to analyze how a subject uses a hand grasp neuroprosthesis to perform activities of daily living. The objects will also be useful in comparing different methods of controlling the neuroprosthesis and in evaluating future changes in the neuroprosthetic system. Assessment trials with these two instrumented objects were performed quickly in an outpatient clinic setting.
Ease of Activities of Daily Living with Conventional and Multigrip Myoelectric Hands
JPO Journal of Prosthetics and Orthotics, 2015
Introduction: The human hand is greatly complex and makes it possible to manipulate and hold objects using many different grips, whereas the function of traditional myoelectric prosthetic hands is dramatically limited, offering only the tripod grip. Therefore, amputees use the prosthesis actively for only about 50% of activities of daily living (ADLs). The purpose of this study was to investigate whether the Michelangelo hand (Otto Bock HealthCare GmbH, Duderstadt, Germany) offering more grip modes as well as a flexible wrist improves function and reduces perceived difficulty of performing ADLs in comparison to conventional myoelectric hands. Materials and Methods: A questionnaire that combined the validated Orthotics and Prosthetics User SurveyYUpper Extremity Functional Status (OPUS-UEFS) and the Prosthetic Upper Extremity Functional Index (PUFI) was used to assess perceived difficulty and usefulness of the prosthesis in performing 23 ADLs. Patients completed this questionnaire at baseline for their existing prosthetic hand and after a minimum of 4 weeks of use of the Michelangelo hand. Results: Sixteen male transradial amputees with an average age of 41 T 14 years were enrolled. The mean period since amputation was 11.8 T 16.1 years, and the mean duration of Michelangelo use was 12.4 T 7.3 weeks. The Michelangelo hand significantly improved the ease of performing the 23 ADLs in the OPUS-UEFS from 27.0 T 9.7 to 36.4 T 12.7 (p = 0.03). The mean total score for bimanual activities improved highly significantly (p = 0.01) with 26.2 T 8.1 for Michelangelo as compared with 20.0 T 7.1 with the previous hand. Using the Michelangelo hand patients performed significantly more ADLs with ''both hands together with the prosthetic hand used actively to grasp'' as compared with the conventional myoelectric hands (means 9.3 T 4.6 vs. 7.1 T 4.1 ADLs; p = 0.04). In addition, the Michelangelo hand was rated as very useful for significantly more ADLs (9.1 T 4.3 vs. 6.4 T 4.1 ADLs; p = 0.01). Conclusions: These results suggest that the Michelangelo hand offering more grip types and functional hand positions as well as a flexible wrist may be used more actively and for more ADLs. These effects seem to be promoted by a reduced perceived difficulty to perform many ADLs as Michelangelo shortens the functional gap between prosthetic and sound human hands.
Quantitative assessment of four men using above-elbow prosthetic control
Archives of Physical Medicine and Rehabilitation, 1993
Quantitative assessment of four men using above-elbow prosthetic control. Arch Phys Med Rehabil 1993;74:720-9. a We studied the relationship between kinematically unconstrained activities of daily living (ADL) tasks and a kinematically constrained task in above-elbow (AE) amputee subjects using myoelectrically controlled prostheses. Four men, 24 to 49 years old, with unilateral AE amputation wore a prosthesis interfaced to a programmable controller to emulate two different elbow control schemes, conventional velocity and a new "natural" controller. Subjects were timed during three ADL tasks-cutting meat, donning socks, and rolling dough-with both controllers. The prosthesis emulator was then connected to a crank device with a handle, and the subjects turned the crank from bottom to top positions in a vertical plane using each controller. Synergistic shoulder-elbow joint coordination required for crank turning was quantified as the maximum slope of the change in elbow torque versus the change in crank-angle. Performance between the two controllers differed significantly for the crank test but not for ADL tasks. One subject did not complete all crank turning tests. Positive canonical correlation of 0.77 was found between time and crank domain measures. We conclude that biomechanical assessments should be integrated with time-based clinical tests to comprehensively evaluate performance of AE amputee subjects with a myoelectric device.