Mary E. Sesto

Effect of Touch Screen Button Size and Spacing on Touch Characteristics of Users With and Without Disabilities

Objective: The aim of this study was to investigate the effect of button size and spacing on touch characteristics (forces, impulses, and dwell times) during a digit entry touch screen task. A secondary objective was to investigate the effect of disability on touch characteristics. Background: Touch screens are common in public settings and workplaces. Although research has examined the effect of button size and spacing on performance, the effect on touch characteristics is unknown. Method: A total of 52 participants (n = 23, fine motor control disability; n = 14, gross motor control disability; n = 15, no disability) completed a digit entry task. Button sizes varied from 10 mm to 30 mm, and button spacing was 1 mm or 3 mm. Results: Touch characteristics were significantly affected by button size. The exerted peak forces increased 17% between the largest and the smallest buttons, whereas impulses decreased 28%. Compared with the fine motor and nondisabled groups, the gross motor group had greater impulses (98% and 167%, respectively) and dwell times (60% and 129%, respectively). Peak forces were similar for all groups. Conclusion: Button size but not spacing influenced touch characteristics during a digit entry task. The gross motor group had significantly greater dwell times and impulses than did the fine motor and nondisabled groups. Application: Research on touch characteristics, in conjunction with that on user performance, can be used to guide human computer interface design strategies to improve accessibility of touch screen interfaces. Further research is needed to evaluate the effect of the exerted peak forces and impulses on user performance and fatigue.

Performance and touch characteristics of disabled and non-disabled participants during a reciprocal tapping task using touch screen technology

Touch screens are becoming more prevalent in everyday environments. Therefore, it is important that this technology is accessible to those with varying disabilities. The objective of the current study was to evaluate performance and touch characteristics (forces, impulses, and dwell times) of individuals with and without a movement disorder during a reciprocal tapping touch screen task. Thirty-seven participants with a motor control disability and 15 non-disabled participants participated. Outcome measures include number of correct taps, dwell time, exerted force, and impulse. Results indicate non-disabled participants had 1.8 more taps than participants with fine motor control disabilities and 2.8 times more than those with gross motor impairments (p<0.05). Additionally, people with gross motor control disabilities demonstrated longer dwell times and greater impulses (p<0.05). The average force used to activate the buttons was 6.2 N, although the button activation force was 0.98 N. Differences in reciprocal tapping and touch characteristics exist between those with and without motor control disabilities. Understanding how people (including those with disabilities) interact with touch screens may allow designers and engineers to ultimately improve usability of touch screen technology.

Hypertonic Dextrose and Morrhuate Sodium Injections (Prolotherapy) for Lateral Epicondylosis (Tennis Elbow). Results of a Single-blind, Pilot-Level, Randomized Controlled Trial

Objective Chronic lateral epicondylosis is common, debilitating, and often refractory. Prolotherapy (PrT) is an injection therapy for tendinopathy. The efficacy of two PrT solutions for chronic lateral epicondylosis was evaluated. Design This study is a three-arm randomized controlled trial. Twenty-six adults (32 elbows) with chronic lateral epicondylosis for 3 mos or longer were randomized to ultrasound-guided PrT with dextrose solution, ultrasound-guided PrT with dextrose-morrhuate sodium solution, or watchful waiting (“wait and see”). The primary outcome was the Patient-Rated Tennis Elbow Evaluation (100 points) at 4, 8, and 16 wks (all groups) and at 32 wks (PrT groups). The secondary outcomes included pain-free grip strength and magnetic resonance imaging severity score. Results The participants receiving PrT with dextrose and PrT with dextrose-morrhuate reported improved Patient-Rated Tennis Elbow Evaluation composite and subscale scores at 4, 8, and/or 16 wks compared with those in the wait-and-see group (P < 0.05). At 16 wks, compared with baseline, the PrT with dextrose and PrT with dextrose-morrhuate groups reported improved composite Patient-Rated Tennis Elbow Evaluation scores by a mean (SE) of 18.7 (9.6; 41.1%) and 17.5 (11.6; 53.5%) points, respectively. The grip strength of the participants receiving PrT with dextrose exceeded that of the PrT with dextrose-morrhuate and the wait and see at 8 and 16 wks (P < 0.05). There were no differences in magnetic resonance imaging scores. Satisfaction was high; there were no adverse events. Conclusions PrT resulted in safe, significant improvement of elbow pain and function compared with baseline status and follow-up data and the wait-and-see control group. This pilot study suggests the need for a definitive trial.

Leveraging Electronic Health Record Systems to Create and Provide Electronic Cancer Survivorship Care Plans: A Pilot Study

PURPOSE The Institute of Medicine (IOM) recommends cancer survivors receive survivorship care plans after completing active cancer treatment. However, care plan creation requires significant time and effort, contributing to diminished adoption of this recommendation. Electronic health record (EHR) systems have been proposed as a solution. We assessed the feasibility of creating and delivering care plans within an EHR system. METHODS Thirty-eight breast cancer survivors without existing care plans were recruited during a follow-up visit to their primary oncologist. Using an EHR template, an oncologist created an individualized care plan for each participant. Time spent creating each plan was recorded. Participant use and feedback were collected. RESULTS Participants enrolled a median of 19.7 months after diagnosis (range, 4.3 to 57 months). A minority of IOM-recommended plan elements could be automatically imported without any manual entry. The majority of elements required interpretation and manual import by the clinician. However, with an established infrastructure for importing elements, the time needed to create a care plan electronically was short (median, 3 minutes; range 2 to 12 minutes). Most survivors (n = 36; 95%) successfully accessed their care plans online and spent a median of 12 minutes (range, 0.5 to 61.9 minutes) reviewing them. Survivors perceived the plans as useful and did not generally report difficulty in accessing them online or understanding content. CONCLUSION Rapid care plan creation and delivery within an EHR is possible. Plans were available to all (survivors, oncologists, primary care physicians) via the EHR. Further research is required to explore the barriers to automating data importation into plans as well as the impact of EHR-integrated plans.

The Effect of Disability and Approach on Touch Screen Performance during a Number Entry Task

As touch screen technology improves in functionality and decreases in price, these input devices are becoming increasingly more integrated into daily life. People are frequently required to interact with touch screens at places ranging from their local grocery stores to airport check-in kiosks. Since it is becoming necessary for people to use touch screens in order to access needed products or services, we conducted an experiment to examine how individuals with varying motor control disabilities perform on a simple number entry task. Since some individuals may also be wheelchair users, and the Americans with Disabilities Act Accessibility Guidelines allows for the touch screen to be approachable by a wheelchair user from the front or parallel (side), the effect of approach on performance was also evaluated. Participants with and without motor control disabilities, including wheelchair users, performed a number entry task on a number pad with different combinations of button and gap sizes, while seated at a touch screen kiosk. Results revealed that participants with motor control impairments had significantly more inaccurate touches overall than participants without. Performance from the front orientation was significantly more accurate than from the side for all participants, regardless of the presence of a motor control disability. Results from this study may be used to guide design of touch screen accessibility for individuals with motor control disabilities and wheelchair users.

Effect of sitting or standing on touch screen performance and touch characteristics.

Objective: The aim of this study was to evaluate the effect of sitting and standing on performance and touch characteristics during a digit entry touch screen task in individuals with and without motor-control disabilities. Background: Previously, researchers of touch screen design have not considered the effect of posture (sitting vs. standing) on touch screen performance (accuracy and timing) and touch characteristics (force and impulse). Method: Participants with motor-control disabilities (n = 15) and without (n = 15) completed a four-digit touch screen number entry task in both sitting and standing postures. Button sizes varied from 10 mm to 30 mm (5-mm increments), and button gap was 3 mm or 5 mm. Results: Participants had more misses and took longer to complete the task during standing for smaller button sizes (<20 mm). At larger button sizes, performance was similar for both sitting and standing. In general, misses, time to complete task, and touch characteristics were increased for standing. Although disability affected performance (misses and timing), similar trends were observed for both groups across posture and button size. Conclusion: Standing affects performance at smaller button sizes (<20 mm). For participants with and without motor-control disabilities, standing led to greater exerted force and impulse. Application: Along with interface design considerations, environmental conditions should also be considered to improve touch screen accessibility and usability.

Functional Tests to Quantify Recovery Following Carpal Tunnel Release

BACKGROUND An objective test is needed to evaluate outcome following carpal tunnel release. A method to evaluate sensory and motor function related to carpal tunnel syndrome was investigated. METHODS Thirty-six candidates for carpal tunnel surgical procedures underwent a physical examination and nerve-conduction studies and completed a survey regarding symptoms. A battery of psychomotor and sensory tests was administered bilaterally immediately before surgery and again six weeks after surgery. The outcome variables included dynamic sensory gap-detection thresholds and rapid pinch-and-release rates. RESULTS The average gap-detection threshold for the index finger in the surgical-treatment group demonstrated a 43% improvement, decreasing from 0.14 mm preoperatively to 0.08 mm at six weeks postoperatively (p < 0.01). The average gap-detection threshold for the index finger in the non-surgical-treatment group demonstrated no significant improvement, decreasing from 0.10 mm preoperatively to 0.08 mm postoperatively (p = 0.10). With the upper force level set at 10% of the maximum voluntary contraction, the average pinch rate in the surgical-treatment group demonstrated a 20% improvement, increasing from 6.65 pinches per second preoperatively to 7.96 pinches per second postoperatively (p < 0.001). The average pinch rate in the non-surgical-treatment group demonstrated a 7% improvement, increasing from 6.89 pinches per second preoperatively to 7.37 pinches per second at six weeks postoperatively (p < 0.05). CONCLUSIONS Measurable and significantly greater improvement was observed when the surgical-treatment group was compared with the non-surgical-treatment group in terms of these two sensory and psychomotor functional testing outcomes at six weeks. LEVEL OF EVIDENCE Therapeutic study, Level II-1 (prospective cohort study). See Instructions to Authors for a complete description of levels of evidence.

Relationships Between Biomechanics, Tendon Pathology, and Function in Individuals With Lateral Epicondylosis

STUDY DESIGN Single-cohort descriptive and correlational study. OBJECTIVES To investigate the relationships between tendon pathology, biomechanical measures, and self-reported pain and function in individuals with chronic lateral epicondylosis. BACKGROUND Lateral epicondylosis has a multifactorial etiology and its pathophysiology is not well understood. Consequently, treatment remains challenging, and lateral epicondylosis is prone to recurrence. While tendon pathology, pain system changes, and motor impairments due to lateral epicondylosis are considered related, their relationships have not been thoroughly investigated. METHODS Twenty-six participants with either unilateral (n = 11) or bilateral (n = 15) chronic lateral epicondylosis participated in this study. Biomechanical measures (grip strength, rate of force development, and electromechanical delay) and measures of tendon pathology (magnetic resonance imaging and ultrasound) and self-reported pain and function (Patient-Rated Tennis Elbow Evaluation) were performed. Partial Spearman correlations, adjusting for covariates (age, gender, weight, and height), were used to evaluate the relationship between self-reported pain, function, and biomechanical and tendon pathology measures. RESULTS Statistically significant correlations between biomechanical measures and the Patient-Rated Tennis Elbow Evaluation ranged in magnitude from 0.44 to 0.68 (P<.05); however, no significant correlation was observed between tendon pathology (magnetic resonance imaging and ultrasound) measures and the Patient-Rated Tennis Elbow Evaluation (r = -0.02 to 0.31, P>.05). Rate of force development had a stronger correlation (r = 0.54-0.68, P<.05) with self-reported function score than with grip strength (r = 0.35-0.47, P<.05) or electromechanical delay (r = 0.5, P<.05). CONCLUSION Biomechanical measures (pain-free grip strength, rate of force development, electromechanical delay) have the potential to be used as outcome measures to monitor progress in lateral epicondylosis. In comparison, the imaging measures (magnetic resonance imaging and ultrasound) were useful for visualizing the pathophysiology of lateral epicondylosis. However, the severity of the pathophysiology was not related to pain and function, indicating that imaging measures may not provide the best clinical assessment.

Effect of Lateral Epicondylosis on Grip Force Development

STUDY DESIGN Case-Control. INTRODUCTION Although it is well known that grip strength is adversely affected by lateral epicondylosis (LE), the effect of LE on rapid grip force generation is unclear. PURPOSE OF THE STUDY To evaluate the effect of LE on the ability to rapidly generate grip force. METHODS Twenty-eight participants with LE (13 unilateral and 15 bilateral LE) and 13 healthy controls participated in this study. A multiaxis profile dynamometer was used to evaluate grip strength and rapid grip force generation. The ability to rapidly produce force is composed of the electromechanical delay and rate of force development. Electromechanical delay is defined as the time between the onset of electrical activity and the onset of muscle force production. The Patient-rated Tennis Elbow Evaluation (PRTEE) questionnaire was used to assess pain and functional disability. Magnetic resonance imaging was used to evaluate tendon degeneration. RESULTS LE-injured upper extremities had lower rate of force development (50 lb/sec, confidence interval [CI]: 17, 84) and less grip strength (7.8 lb, CI: 3.3, 12.4) than nonnjured extremities. Participants in the LE group had a longer electromechanical delay (- 59% , CI: 29, 97) than controls. Peak rate of force development had a higher correlation (r = 0.56; p<0.05) with PRTEE function than grip strength (r = 0.47; p<0.05) and electromechanical delay (r = 0.30; p>0.05) for participants with LE. In addition to a reduction in grip strength, those with LE had a reduction in rate of force development and an increase in electromechanical delay. CONCLUSIONS Collectively, these changes may contribute to an increase in reaction time, which may affect risk for recurrent symptoms. These findings suggest that therapists may need to address both strength and rapid force development deficits in patients with LE. LEVEL OF EVIDENCE 3B.

Reliability and Validity of the Multiaxis Profile Dynamometer with Younger and Older Participants

STUDY DESIGN Clinical Measurement. INTRODUCTION Grip strength has been administered for many years with a wide variety of instruments and for very different purposes. PURPOSE OF THE STUDY To examine the reliability and validity of a new grip measurement device, the multiaxis profile (MAP) dynamometer, compared with the Baseline dynamometer (Fabrication Enterprises Inc., White Plains, NY) and vigorimeter. METHODS Twenty-eight participants (<30 yr, n=14; and >65 yr, n=14) completed grip strength testing using all three devices. Measurements were obtained at baseline and one to two weeks later. RESULTS Intraclass correlation coefficients (ICCs) for the MAP ranged from 0.94 to 0.99. The other two devices had ICCs of 0.95-0.98. Correlations among the MAP dynamometer, the Baseline dynamometer, and the vigorimeter were 0.78-0.90. The results indicate high concurrent validity among all the three devices and that all devices are reliable instruments to measure the grip strength of both younger and older adults. CONCLUSIONS In addition to measuring grip strength, the MAP dynamometer measures other grip-related information, such as grip force vectors, rate of force buildup, and force variability. This additional grip information may improve our understanding of hand function and changes because of aging. LEVEL OF EVIDENCE n/a.