Validation of Proprietary and Novel Step-counting Algorithms for Individuals Ambulating With a Lower Limb Prosthesis.

OBJECTIVE: To compare the accuracy and reliability of 10 different accelerometer-based step-counting algorithms for individuals with lower limb loss, accounting for different clinical characteristics and real-world activities. DESIGN: Cross-sectional study. SETTING: General community setting (ie, institutional research laboratory and community free-living). PARTICIPANTS: Forty-eight individuals with a lower limb amputation (N=48) wore an ActiGraph (AG) wGT3x-BT accelerometer proximal to the foot of their prosthetic limb during labeled indoor/outdoor activities and community free-living. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Intraclass correlation coefficient (ICC), absolute and root mean square error (RMSE), and Bland Altman plots were used to compare true (manual) step counts to estimated step counts from the proprietary AG Default algorithm and low frequency extension filter, as well as from 8 novel algorithms based on continuous wavelet transforms, fast Fourier transforms (FFTs), and peak detection. RESULTS: All algorithms had excellent agreement with manual step counts (ICC>0.9). The AG Default and FFT algorithms had the highest overall error (RMSE=17.81 and 19.91 steps, respectively), widest limits of agreement, and highest error during outdoor and ramp ambulation. The AG Default algorithm also had among the highest error during indoor ambulation and stairs, while a FFT algorithm had the highest error during stationary tasks. Peak detection algorithms, especially those using pre-set parameters with a trial-specific component, had among the lowest error across all activities (RMSE=4.07-8.99 steps). CONCLUSIONS: Because of its simplicity and accuracy across activities and clinical characteristics, we recommend the peak detection algorithm with set parameters to count steps using a prosthetic-worn AG among individuals with lower limb loss for clinical and research applications.

Effectiveness of a Web-Based Direct-to-User Transfer Training Program: A Randomized Controlled Trial.

OBJECTIVE: To determine the effectiveness of a web-based, direct-to-user transfer training program in improving transfer quality and maintaining improvements for up to 1 month after training as compared with a control group. DESIGN: Randomized controlled trial with participants randomized to an immediate intervention group (IIG) or waitlist control group (WLCG) that received the training after a 6-month delay. SETTING: Wherever the participants accessed the web-based training, likely the home environment. PARTICIPANTS: Convenience sample of full-time wheelchair users (N=72; IIG, n=34; WLCG, n=38 for between-group analysis, n=48 for combined within-group analysis) with spinal cord injury or disorder who were able to independently perform a lateral scoot transfer. INTERVENTIONS: Self-paced, web-based transfer training module. MAIN OUTCOME MEASURES: Transfer Assessment Instrument Questionnaire (TAI-Q) score at baseline, 1 month, and 6 months postbaseline (WLCG only), immediately posttraining, and 1 month posttraining. The TAI-Q is an 18-item self-assessment that covers several aspects of a quality transfer. RESULTS: The IIG significantly increased particpants' baseline TAI-Q score from 6.91±0.98 to 7.79±1.12 (P<.001) by 1 month posttraining. The WLCG also increased from baseline to the 1-month postbaseline assessment (from 6.52±1.13 to 7.00±1.09; P=.014), potentially from learning effects secondary to self-assessment with the TAI-Q. The extent of change over time did not differ significantly between the IIG and WLCG from baseline to 1 month (P=.169). However, significant improvements in TAI-Q scores were still evident after the training for the WLCG (P<.001). Those with a lower pretraining TAI-Q score and more shoulder pain were most likely to benefit from the training. CONCLUSIONS: Repeated TAI-Q self-assessments likely contributed to improved transfer quality, with web-based training having an additive effect. Wheelchair users are likely to benefit from transfer training and self-assessment of transfer quality in their home environments. This has the potential to decrease injury risk while avoiding barriers to in-person training.

Intra- and Interrater Reliability of Remote Assessment of Transfers by Wheelchair Users Using the Transfer Assessment Instrument (Version 4.0).

OBJECTIVE: To evaluate the reliability, standard error of measurement, minimum detectable change, and item-level consistency of the Transfer Assessment Instrument (TAI) version 4.0 when used to evaluate transfer quality remotely. DESIGN: Participants transferred from their wheelchair to a mat table (transfer 1), repeated this after a 10-minute delay to assess intrarater reliability (transfer 2), and repeated this 1-2 days later to assess test-retest reliability (transfer 3). Each transfer was scored in person by 4 raters and asynchronously by a remote clinician rater. SETTING: 2017 National Veterans Wheelchair Games. PARTICIPANTS: Convenience sample of 44 full-time wheelchair users (N=44). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: TAI total score, subscores (wheelchair setup, body setup, flight/landing), and item scores (15 items). RESULTS: Moderate to excellent reliability was found when scoring remotely for TAI total and subscores for intrarater (intraclass correlation coefficient (ICC(3,1)=0.687-0.854), test-retest (ICC(3,1)=0.695-0.836), and interrater reliability (ICC(3,5)=0.746-0.962). Remote rater total score and flight/landing subscore were greater (indicating higher transfer quality) compared to the average in-person raters (P=.021 and P=.005, respectively). There were no differences between transfers 1-3 in remote rater scores. Item-level percentage agreement between the remote rater and in-person exceeded the 75% cutoff for clinical utility for all items. CONCLUSIONS: The TAI is a reliable outcome measure for assessing transfer technique remotely.

Toward Improving the Prediction of Functional Ambulation After Spinal Cord Injury Through the Inclusion of Limb Accelerations During Sleep and Personal Factors.

OBJECTIVE: To determine if functional measures of ambulation can be accurately classified using clinical measures; demographics; personal, psychosocial, and environmental factors; and limb accelerations (LAs) obtained during sleep among individuals with chronic, motor incomplete spinal cord injury (SCI) in an effort to guide future, longitudinal predictions models. DESIGN: Cross-sectional, 1-5 days of data collection. SETTING: Community-based data collection. PARTICIPANTS: Adults with chronic (>1 year), motor incomplete SCI (N=27). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Ambulatory ability based on the 10-m walk test (10MWT) or 6-minute walk test (6MWT) categorized as nonambulatory, household ambulator (0.01-0.44 m/s, 1-204 m), or community ambulator (>0.44 m/s, >204 m). A random forest model classified ambulatory ability using input features including clinical measures of strength, sensation, and spasticity; demographics; personal, psychosocial, and environmental factors including pain, environmental factors, health, social support, self-efficacy, resilience, and sleep quality; and LAs measured during sleep. Machine learning methods were used explicitly to avoid overfitting and minimize the possibility of biased results. RESULTS: The combination of LA, clinical, and demographic features resulted in the highest classification accuracies for both functional ambulation outcomes (10MWT=70.4%, 6MWT=81.5%). Adding LAs, personal, psychosocial, and environmental factors, or both increased the accuracy of classification compared with the clinical/demographic features alone. Clinical measures of strength and sensation (especially knee flexion strength), LA measures of movement smoothness, and presence of pain and comorbidities were among the most important features selected for the models. CONCLUSIONS: The addition of LA and personal, psychosocial, and environmental features increased functional ambulation classification accuracy in a population with incomplete SCI for whom improved prognosis for mobility outcomes is needed. These findings provide support for future longitudinal studies that use LA; personal, psychosocial, and environmental factors; and advanced analyses to improve clinical prediction rules for functional mobility outcomes.

Changes in Internet Use Over Time Among Individuals with Traumatic Spinal Cord Injury.

OBJECTIVE: To investigate the changes in total internet and mobile internet use over time and determine how demographic characteristics are related to changes in internet and mobile internet use among individuals with spinal cord injury (SCI). DESIGN: Cross-sectional analysis of a multicenter cohort study. SETTING: National SCI Database. PARTICIPANTS: Individuals with traumatic SCI with follow-up data collected between 2012 and 2018 (N=13,622). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Proportion of sample reporting internet use at all or through a mobile device over time and specifically in 2018. RESULTS: The proportion of internet users increased from 77.7% in 2012 to 88.1% in 2018. Older participants (P<.001); those with lower annual income (P<.001), less education (P<.001), non-White race or Hispanic ethnicity (P<.001), or motor incomplete tetraplegia (P=.004); and men (P=.035) were less likely to use the internet from 2012-2018. By 2018, there were no longer differences in internet use based on race and ethnicity (P=.290) or sex (P=.066). Mobile internet use increased each year (52.4% to 87.7% of internet users from 2012-2018), with a participant being 13.7 times more likely to use mobile internet in 2018 than 2012. Older age (P<.001), income <$50,000 (P<.001), high school diploma or less (P=.011), or non-Hispanic White race/ethnicity (P=.001) were associated with less mobile internet use over time. By 2018, there were no differences in mobile internet use by education (P=.430), and only participants with incomes >$75,000 per year had greater odds of mobile internet use (P=.016). CONCLUSIONS: Disparities associated with internet access are decreasing likely as a result of mobile device use. Increased internet access offers an important opportunity to provide educational and training materials to frequently overlooked groups of individuals with SCI.

Limb accelerations during sleep are related to measures of strength, sensation, and spasticity among individuals with spinal cord injury.

BACKGROUND: To evaluate the relationship between measures of neuromuscular impairment and limb accelerations (LA) collected during sleep among individuals with chronic spinal cord injury (SCI) to provide evidence of construct and concurrent validity for LA as a clinically meaningful measure. METHODS: The strength (lower extremity motor score), sensation (summed lower limb light touch scores), and spasticity (categorized lower limb Modified Ashworth Scale) were measured from 40 adults with chronic (≥ 1 year) SCI. Demographics, pain, sleep quality, and other covariate or confounding factors were measured using self-report questionnaires. Each participant then wore ActiGraph GT9X Link accelerometers on their ankles and wrist continuously for 1-5 days to measure LA from movements during sleep. Regression models with built-in feature selection were used to determine the most relevant LA features and the association to each measure of impairment. RESULTS: LA features were related to measures of impairment with models explaining 69% and 73% of the variance (R²) in strength and sensation, respectively, and correctly classifying 81.6% (F1-score = 0.814) of the participants into spasticity categories. The most commonly selected LA features included measures of power and frequency (frequency domain), movement direction (correlation between axes), consistency between movements (relation to recent movements), and wavelet energy (signal characteristics). Rolling speed (change in angle of inclination) and movement smoothness (median crossings) were uniquely associated with strength. When LA features were included, an increase of 72% and 222% of the variance was explained for strength and sensation scores, respectively, and there was a 34% increase in spasticity classification accuracy compared to models containing only covariate features such as demographics, sleep quality, and pain. CONCLUSION: LA features have shown evidence of having construct and concurrent validity, thus demonstrating that LA are a clinically-relevant measure related to lower limb strength, sensation, and spasticity after SCI. LA may be useful as a more detailed measure of impairment for applications such as clinical prediction models for ambulation.

Investigating the Efficacy of Web-Based Transfer Training on Independent Wheelchair Transfers Through Randomized Controlled Trials.

OBJECTIVES: To determine the efficacy of a web-based transfer training module at improving transfer technique across 3 groups: web-based training, in-person training (current standard of practice), and a waitlist control group (WLCG); and secondarily, to determine subject factors that can be used to predict improvements in transfer ability after training. DESIGN: Randomized controlled trials. SETTING: Summer and winter sporting events for disabled veterans. PARTICIPANTS: A convenience sample (N=71) of manual and power wheelchair users who could transfer independently. INTERVENTIONS: An individualized, in-person transfer training session or a web-based transfer training module. The WLCG received the web training at their follow-up visit. MAIN OUTCOME MEASURE: Transfer Assessment Instrument (TAI) part 1 score was used to assess transfers at baseline, skill acquisition immediately posttraining, and skill retention after a 1- to 2-day follow-up period. RESULTS: The in-person and web-based training groups improved their median (interquartile range) TAI scores from 7.98 (7.18-8.46) to 9.13 (8.57-9.58; P<.01), and from 7.14 (6.15-7.86) to 9.23 (8.46-9.82; P<.01), respectively, compared with the WLCG that had a median score of 7.69 for both assessments (baseline, 6.15-8.46; follow-up control, 5.83-8.46). Participants retained improvements at follow-up (P>.05). A lower initial TAI score was found to be the only significant predictor of a larger percent change in TAI score after receiving training. CONCLUSIONS: Transfer training can improve technique with changes retained within a short follow-up window, even among experienced wheelchair users. Web-based transfer training demonstrated comparable improvements to in-person training. With almost half of the United States population consulting online resources before a health care professional, web-based training may be an effective method to increase knowledge translation.

Reliability of home-based remote and self-assessment of transfers using the Transfer Assessment Instrument among wheelchair users with spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To evaluate the reliability of home-based remote and self-assessment of transfer quality using the Transfer Assessment Instrument (TAI) among wheelchair users with spinal cord injury (SCI). SETTING: Participant's home environment. METHODS: Eighteen wheelchair users with SCI transferred from their wheelchair to a surface of their choice (bed, sofa, or bench) in their homes. During a live video conference, the transfer was recorded and evaluated live using the TAI (rater 1). Participants completed a self-assessment of their transfer using the TAI- questionnaire (TAI-Q). Two additional raters (raters 2 & 3) completed asynchronous assessments by watching recorded videos. Interrater reliability was assessed using Intraclass Coefficient Correlations (ICC) to compare rater 1 with the average of raters 2 & 3 and TAI-Q. Intrarater reliability was assessed by rater 1 completing another TAI by watching the recorded videos after a 4-week delay. Assessments were compared using paired sample t-tests and level of agreement between TAI scores was evaluated using Bland-Altman plots. RESULTS: Moderate to good interrater and good intrarater reliability were found for the total TAI score with ICCs: 0.57-0.90 and 0.90, respectively. Moderate to good intrarater and interrater reliability were found for all TAI subscores (ICC: 0.60-0.94) except for interrater reliability of flight/landing which was poor (ICC: 0.20). Bland-Altman plots indicate no systematic bias related to the measurement of error. CONCLUSIONS: The TAI is a reliable outcome measure for assessing the wheelchair and body setup phases of home-based transfers remotely and through self-assessment among individuals with SCI.

Concurrent Validity and Reliability of the Transfer Assessment Instrument Questionnaire as a Self-Assessment Measure.

OBJECTIVES: To evaluate the psychometric properties of the Transfer Assessment Instrument Questionnaire (TAI-Q), a self-assessment measure to evaluate transfer quality compared with clinician-reported measures. DESIGN: Participants self-assessed transfers from their wheelchair to a mat table using the TAI-Q. For session 1, participants self-assessed their transfer both before and after reviewing a video of themselves completing the transfer (session 1). Self-assessment was completed for another transfer after a 10-minute delay (session 2, intrarater reliability) and after a 1- to 2-day delay (session 3, test-retest reliability). Self-assessment was compared with a criterion standard of an experienced clinician scoring the same transfers with the Transfer Assessment Instrument (TAI) version 4.0 (concurrent validity). SETTING: 2017 National Veterans Wheelchair Games. PARTICIPANTS: Convenience sample of full-time wheelchair users (N=44). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: TAI-Q and TAI. RESULTS: After video review of their transfer, acceptable levels of reliability were demonstrated for total TAI-Q score for intrarater (intraclass correlation [ICC], 0.627) and test-retest reliability (ICC, 0.705). Moderate to acceptable concurrent validity was demonstrated with the TAI (ICC, 0.554-0.740). Participants tended to underestimate the quality of their transfer (reported more deficient items) compared with the TAI. However, this deficit decreased and reliability improved from pre-video review to post-video review and from session 1 to session 2. The minimum detectable change indicated that a change of 1.63 to 2.21 in the TAI-Q total score is needed to detect a significant difference in transfer skills. CONCLUSIONS: When paired with video review, the TAI-Q demonstrates moderate to acceptable levels of reliability and validity for the total score. Self-assessment was completed quickly (<5min) and could help to potentially screen for deficiencies in transfer quality and opportunities for intervention.

Reliability and Validity of the Revised Transfer Assessment Instrument.

Background: Proper transfer technique is associated with improved biomechanics and decreased pain and pathology. However, many users do not use proper technique, and appropriate assessment and training are needed to address these deficits. The transfer assessment instrument (TAI) 4.0 was designed to meet those needs and improve on past versions by removing the need for clinician training, shortening administration time, and simplifying question content. Objectives: Evaluate the psychometric properties of the TAI 4.0. Methods: A convenience sample of full-time wheelchair users was scored on multiple transfers by four raters to assess interrater, intrarater, and test-retest reliability and concurrent validity of the TAI 4.0. Each user also was scored using a visual analog scale (VAS). Results: For 44 participants, the mean TAI 4.0 and VAS across all transfers were 7.58 ± 1.12 and 7.44 ± 1.78, respectively, and scores were significantly correlated (r = 0.52-0.7). VAS scores were more strongly influenced by the flight/landing and body setup phases of the transfer. There were no significant associations between TAI 4.0 score and demographics. Intraclass correlation coefficients (ICC) ranged from 0.80 to 0.85 for interrater reliability, 0.60 to 0.76 for intrarater reliability, and 0.55 to 0.76 for test-retest reliability. The minimum detectable change (MDC) for the total score ranged from 1.02 to 1.30. Conclusion: The TAI 4.0 provides reliable and valid quantitative assessment of an individual's transfer without the need for comprehensive training, as is the case with the TAI 3.0. The tool can be completed in 3 minutes (average) in a clinical setting with only a ruler and goniometer.

Biomechanical Analysis of Internal Fixation Methods for Distal Interphalangeal Joint Arthrodesis.

BACKGROUND: The biomechanical performance of distal interphalangeal joint (DIPJ) fixation techniques in response to cyclic and load-to-failure bending loads is generally unknown. The purpose of this study is to assess the performance of 4 commonly used techniques for DIP arthrodesis. METHODS: Phalanges were fixed by one of the following techniques: (1) 2 parallel Kirschner wires (K-wires), (2) 1 longitudinal K-wire and 1 oblique K-wire, (3) an Acutrak® 2 Micro headless compression screw, or (4) 90-90 wiring. The phalanges were loaded in cantilever bending on the palmar side of the phalange for 3000 cycles, then loaded-to-failure. RESULTS: The 90-90 wiring was significantly worse than the other 3 methods in 9 of 10 parameters analyzed. Both K-wire methods and the screw produced similar results in nearly all parameters. CONCLUSIONS: Given the lack of difference in biomechanical performance between K-wires and compression screws, consideration should be given to other factors such as cost and complication profiles when choosing an implant for DIPJ fusion.