Growth/differentiation factor 15 causes TGFß-activated kinase 1-dependent muscle atrophy in pulmonary arterial hypertension.

INTRODUCTION: Skeletal muscle dysfunction is a clinically important complication of pulmonary arterial hypertension (PAH). Growth/differentiation factor 15 (GDF-15), a prognostic marker in PAH, has been associated with muscle loss in other conditions. We aimed to define the associations of GDF-15 and muscle wasting in PAH, to assess its utility as a biomarker of muscle loss and to investigate its downstream signalling pathway as a therapeutic target. METHODS: GDF-15 levels and measures of muscle size and strength were analysed in the monocrotaline (MCT) rat, Sugen/hypoxia mouse and in 30 patients with PAH. In C2C12 myotubes the downstream targets of GDF-15 were identified. The pathway elucidated was then antagonised in vivo. RESULTS: Circulating GDF-15 levels correlated with tibialis anterior (TA) muscle fibre diameter in the MCT rat (Pearson r=-0.61, p=0.003). In patients with PAH, plasma GDF-15 levels of <564 pg/L predicted those with preserved muscle strength with a sensitivity and specificity of ≥80%. In vitro GDF-15 stimulated an increase in phosphorylation of TGFß-activated kinase 1 (TAK1). Antagonising TAK1, with 5(Z)-7-oxozeaenol, in vitro and in vivo led to an increase in fibre diameter and a reduction in mRNA expression of atrogin-1 in both C2C12 cells and in the TA of animals who continued to grow. Circulating GDF-15 levels were also reduced in those animals which responded to treatment. CONCLUSIONS: Circulating GDF-15 is a biomarker of muscle loss in PAH that is responsive to treatment. TAK1 inhibition shows promise as a method by which muscle atrophy may be directly prevented in PAH. TRIAL REGISTRATION NUMBER: NCT01847716; Results.

Forces involved when sliding a patient up in bed.

BACKGROUND: This study investigated the effects of 3 different types of slide sheets upon hand forces while sliding a patient up in bed. METHODS: The sheets used included the reusable Arjo Maxislide, the McAuley disposable sheet, and a standard cotton sheet. Hand forces were measured from 38 male and female participants as they slid a 'patient' up in bed. A repeated measures ANOVA with 5 levels to the repeated factor (number of sheets and sheet type) was used, along with post-hoc repeated measures contrasts to compare differences between each condition. RESULTS: A significant reduction in required force occurred when using the friction reducing sheets as compared to the cotton sheets when used according to manufacturer recommendations, as well as a reduction in one of the single friction reducing sheet categories compared to the cotton. However, it is important to note that there was still substantial force being placed on the participants. CONCLUSIONS: This study illustrates the importance of using friction reducing slide sheets while engaging in manual patient handling. Future research should investigate the forces involved with other friction reducing materials and methods as well as the possibility of combining said materials and methods.

Men in Occupational Therapy: Issues, Factors, and Perceptions.

OBJECTIVE: Relatively few men are occupational therapy practitioners in the United States. Little research has examined issues germane to men working in the profession. The objective of this study was to investigate perceptions, issues, and factors surrounding male occupational therapy practitioners. METHOD: A survey link was emailed to 9,467 licensed occupational therapy practitioners in Ohio; 699 participants responded, yielding a response rate of 7.66%. RESULTS: Male and female participants provided both similar and significantly different responses to the survey questions. Differences generally involved responses to questions on personal finances and client education. Themes were identified from the open-ended questions regarding gender stereotypes. CONCLUSION: Although male and female practitioners differed in opinion on several issues and perceptions related to the profession, in general they were happy with their career choice. Specifically, participants expressed that they enjoyed their job, contributed to society, and had a sense of job security, regardless of gender.

Jump-landing biomechanics following a 4-week real-time feedback intervention and retention.

BACKGROUND: Poor neuromuscular control can increase the risk of anterior cruciate ligament (ACL) injury. Landing with decreased knee and hip flexion may increase the risk of lower extremity injury. Feedback interventions have demonstrated changes in jump-landing biomechanics. Traditional feedback (TF), provided after task completion, includes critical factors to focus on during jump-landing. Real-time feedback (RTF), provided while completing the task, may be superior for improving jump-landing biomechanics. This investigation evaluated the effect of RTF+TF compared to TF and a control group in changing lower extremity jump-landing biomechanics following a 4-week feedback intervention and a 1-week no feedback retention. METHODS: Participants completed 12 feedback sessions over 4 weeks. At each session, participants performed 6 sets of 6 jumps off a 30 cm box. Participants were provided TF or RTF+TF following each set of jumps. Participants were tested at baseline, immediately following the 4-week intervention and following a 1-week retention. The control group was tested at two time points 4 weeks apart. FINDINGS: Acquisition analysis: RTF+TF and TF groups demonstrated greater change in peak hip flexion angles and peak knee flexion angles compared to the control group following the intervention. TF and RTF+TF groups demonstrated a greater decrease in peak vertical ground reaction force compared to the control group. No significant differences were observed between groups in the retention analysis. INTERPRETATION: This study provides evidence of acquisition of biomechanical changes following a 4-week feedback intervention. Future research should further investigate the retention of biomechanical changes, the optimal length of feedback interventions and transfer of learned biomechanics to similar athletic tasks.

Degree of Preference and Its Influence on Motor Control When Reaching for Most Preferred, Neutrally Preferred, and Least Preferred Candy.

The objective of this study was to determine whether reaching for objects with varying levels of preference associated with them elicited influenced motor control in a reaching task. Forty healthy adults were asked to reach for seven different types of candy, which they ranked by personal preference from being the most preferred to the least preferred. In this repeated measures design, data were analyzed on 39 participants who tended to demonstrate greater movement efficiency in movement time and movement units when reaching for candy in which they associated with greater preference (p < .0 167). Although no differences were found between conditions with peak velocity and percentage of movement time to peak velocity (p > .0167), these dependent variables appeared to trend in the direction of similar movement efficiency. Therapists can use this knowledge to help guide clinical reasoning when designing treatment plans and approaches. Future research is needed to further examine intensity along the continuum of preference and its implications for occupational therapy practice.

Occupational Embeddedness, Perceived Risk, and the Quality of Reach Motion in Females Aged 7 to 9 Years.

The perceived meaning ascribed to objects can influence the motor control efficiency in adults when reaching. However, little is known whether the same phenomenon occurs in pediatric females. Twenty-seven girls aged 7 to 9 years recruited from Girl Scout Brownie troupes and afterschool programs were asked to reach for plastic and porcelain teacups in the context of a "tea party" scenario. No differences were found in most of the motion capture variables (p > .05), and effect sizes were small. It is likely that the perceived meaning of the tea party was so robust that it overwhelmed any perceived differences inherent between the two conditions. Future research is needed to clarify the age at which children can qualitatively discern meaningful differences between objects.

Efficiency of unimanual and bimanual reach in persons with and without stroke.

BACKGROUND: Deficiencies in motor control are one of the largest challenges faced by stroke survivors in regaining their independence after stroke. OBJECTIVE: This study investigated movement efficiency in people with and without stroke during both unimanual and bimanual upper extremity reaching tasks. METHOD: Twenty-five participants (12 with stroke and 13 age-matched controls) between the ages of 36-69 years randomly experienced testing conditions involving reaching forward unimanually and bimanually at a preferred speed in a single session. Kinematic and kinetic outcomes included movement time, movement units, peak velocity, and percentage of movement time to peak velocity. RESULTS: In stroke participants, the unimpaired limb accommodated its movements to that of the less efficient paretic limb during bimanual conditions indicating yoked movement efficiency because its performance was more efficient (P < 0.05) in unilateral trials, whereas the impaired limb's performance did not differ between the unimanual and bimanual conditions (P>0.05). Control subjects elicited greater movement efficiency than participants with stroke. CONCLUSION: Motor efficiency of the unimpaired upper extremity may be adversely influenced when yoked with the impaired limb during symmetrical simple movements in persons with stroke. As such, motor efficiency is not exclusively limited to the impaired side, the effects of which may be task dependent.

Alterations in stride-to-stride variability during walking in individuals with chronic ankle instability.

The aim of this study was to evaluate stride-to-stride variability of the lower extremity during walking in individuals with and without chronic ankle instability (CAI) using a nonlinear analysis. Twenty-five participants with self-reported CAI and 27 healthy control participants volunteered for this study. Participants walked on a motor-driven treadmill for 3 min at their selected speed. Lower extremity kinematics in the sagittal and frontal planes were recorded using a passive retroreflective marker motion capture system. The temporal structure of walking variability was analyzed with sample entropy (SampEn). The CAI group produced lower SampEn values in frontal-plane ankle kinematics compared to the control group (P=.04). No significant group differences were observed for SampEn values of other kinematics (P>.05). Participants with CAI demonstrated less stride-to-stride variability of the frontal plane ankle kinematics compared to healthy controls. Decreased variability of walking patterns demonstrated by participants with CAI indicates that the presence of CAI may be associated with a less adaptable sensorimotor system to environmental changes. The altered sensorimotor function associated with CAI may be targets for clinical interventions, and it is critical to explore how interventions protocols affect sensorimotor system function.

Comparison of caregiver forces required for sliding a patient up in bed using an array of slide sheets.

This study investigated the forces required while performing the common patient handling task of moving a patient up in bed using traditional cotton sheets or friction-reducing slide sheets. Twenty-nine healthy adult participants 18 to 36 years of age were recruited as "patients." Hand forces and lumbar compression and shear forces were calculated on the "caregiver" when performing the repositioning task. Significant differences in lumbar compression and lumbar sagittal shear forces at L4-L5 and at L5-S1 were found among the three sheet types. No difference in peak sum hand force was found between the slide sheets; however, the traditional cotton sheet created the greatest force at the hands and every sheet exceeded the recommended summative hand force of 35 pounds. As such, sliding patients up in bed may contribute to increased risk of musculoskeletal injuries in caregivers.

Choice as a strategy to enhance engagement in a colouring task in children with autism spectrum disorders.

This study investigated the effect of choice on a colouring task in children with autism spectrum disorders (ASD). Children with ASD typically have difficulty engaging in purposeful activities, which makes progress toward skill development difficult in therapeutic or educational settings. Participants included 26 male and female children with ASD, aged 8 to 15 years. In this counterbalanced design, participants either chose which picture to colour or were given a picture to colour. When given a choice, participants spent more time colouring (p=0.005) and used more coloured markers (p=0.016), but did not colour more of the page (p=498). This study demonstrated that when offering a choice in a colouring activity, children with ASD participated and engaged in the colouring task for a longer period of time and used a larger array of markers while doing so. However, associated small effect sizes require caution with generalization. Future research should focus upon offering choice with other age-appropriate activities to determine its efficacy as a useful strategy for facilitating activity engagement for children with ASD.

Safe patient handling curriculum in occupational therapy and occupational therapy assistant programs: A descriptive study of school curriculum within the United States of America.

The purpose of this study was to identify safe patient handling (SPH) curricular content in accredited occupational therapy and occupational therapy assistant programs in the United States of America. A survey was emailed to 155 accredited occupational therapy and 137 accredited occupational therapy assistant programs. With a 39% response rate, most programs addressed SPH curricula by including lectures and lab-based experiences with gait belts, slide boards, and manual transfers while stressing 'safe' body mechanics. There were limited responses regarding curricular-based hands-on experience, evaluation of sit-to-stand lifts, how to safely transfer bariatric persons, and information on "no-lift" policies. While occupational therapists have a central role in teaching SPH to caregivers, it is important to enhance SPH curricula to reduce exposure to musculoskeletal risk, thereby, increasing the health and safety of the occupational therapy workforce as well those whom the profession serves.

A questionnaire of musculoskeletal injuries associated with manual patient lifting in occupational therapy practitioners in the state of ohio.

ABSTRACT The purpose of this study is to investigate the prevalence and type of musculoskeletal injury due to patient handling as well as to ascertain current safe patient handling practices in occupational therapy within the state of Ohio. A questionnaire focusing on safe patient handling issues was e-mailed to 1,113 occupational therapy practitioners in the state of Ohio, with an overall response rate of 26%. Sixty-four percent indicated they were required to transfer patients manually. Of these respondents, 8% indicated receiving an injury, 11% missed days away from work in connection with sustaining an injury, and 12% considered leaving the profession early due to patient handling concerns. The study demonstrated that this sample of occupational therapy practitioners was exposed to occupationally based high-risk situations regarding patient handling with moderate to high incidence rates for musculoskeletal injuries. Additional research is needed to ascertain the status of safe patient handling among occupational therapy practitioners nationwide.

Grasping naturally versus grasping with a reacher in people without disability: motor control and muscle activation differences.

OBJECTIVE: We investigated motor control and muscle activation when reaching for and grasping objects with a reacher compared with the unaided hand. METHOD: In a repeated-measures counterbalanced design, 41 healthy participants with no previous experience using a reacher were randomly assigned to a sequence of four conditions. Movements of the wrist and fingers were recorded using a three-dimensional Qualisys camera system for assessing reach and grasp. Muscle activations from finger and arm flexors and extensors were recorded by surface electromyography. RESULTS: Participants exhibited a smaller grasp aperture, longer reaching time, and more muscle activity when they used a reacher. CONCLUSION: Efficient motor control, which requires both time and practice, is needed to successfully use a reacher. Clients presented with reachers without sufficient time to develop motor skills unique to reacher use may be more likely to abandon this assistive device and fail to benefit from its function.

Long-handled shoehorn length, body mass index, and hip range of motion in healthy female adults.

We examined the effect that long-handled shoehorn (LHSH) length and body mass index (BMI) have on hip range of motion (ROM) in female adults. Thirty-eight female participants were asked to don a shoe using 18-, 24-, and 30-in. LHSHs. Significant differences in hip flexion were found between the 18- and the 24-in. shoehorns and between the 18- and the 30-in. shoehorns. A significant positive relationship was found between BMI and internal rotation for each of the LHSHs. The results suggest that healthy women with low BMLs using a 24- or 30-in. LHSH have the greatest chance of not violating hip flexion or hip internal rotation ROM precautions. Implications suggest that therapists consider individual BMI and available hip ROM before prescribing an LHSH. A follow-up study is needed involving populations who would likely benefit from using LHSHs.

Comparison of required operating forces between floor-based and overhead-mounted patient lifting devices.

This study investigated the differences in required push, pull and rotating forces for moving fully loaded, floor-based and overhead-mounted full body patient lifting devices with simulated patients of varying weight on a floor of optimal design (i.e. level vinyl tile over concrete). A single person operated the lifting devices for all of the tests. Eighteen male and female volunteer participants, ranging in weight from 51 to 146 kg, acted as patients during the lifting tests. For each test, the simulated patients were pushed and pulled for 3.7 linear metres and were rotated while sitting in the lift slings. Force measurements were acquired using two single axis dynamometers affixed to the lifting devices. Results revealed that, in general, operator input force and torque increased with patient weight category and floor-based lifts required greater force and torque compared to the overhead-mounted lift. Comparison of the required forces with published force limits reveals that the required push and pull force from the various patient lift systems, across all weight categories, were generally acceptable to 90% of the female population. The required forces for these patient transfer tasks, however, could exceed maximum acceptable force limits if the floor surfaces were less than ideal, such as floors composed of carpet, wood, or inclined surfaces. Additional research is needed to assess these conditions.

Knowledge of results and learning to tell the time in an adult male with an intellectual disability: a single-subject research design.

The present study investigated whether knowledge of results, in the form of visual and audible feedback, would increase the accuracy of time-telling in an individual with an intellectual disability. A 19-year-old male with mild intellectual disability participated in this A1-B1-A2-B2 single-subject study design. The task involved correctly identifying the time given on a computer. Data, based on the Wilcoxon signed-rank test, showed that the participant demonstrated a greater number of correct responses during the intervention phases. Incorporating knowledge of results into a learning strategy for this individual with intellectual disability resulted in an increased ability to accurately identify the correct time on an analogue clock. There is a need to replicate the study design to increase the external validity and generalization of results. The strategies described in the present study may also be useful for occupational therapists who teach individuals with intellectual disability to gain skills in their everyday activities of daily living (ADLs).

Semantic priming of motor task performance in young adults: implications for occupational therapy.

OBJECTIVE: To investigate whether the performance of a multisegment motor task is influenced by reading a segment-specific action word. METHOD: Twenty-four participants performed tasks that involved reaching for a bottle, grasping it, lifting and placing it on a shelf, and returning their hand to the starting position. At the initiation of each task, participants read either aloud or silently five randomly provided, task-related words (reach, grasp, lift, place, and return). RESULTS: Reading task-related words significantly affected the reach and lift/place segments in the direction of the hypothesis (p < 0.05) but not the return segments. Grasp times were shorter and grasp velocities were higher when participants read aloud or silently the words grasp and place for the grasp segment (p < 0.05). CONCLUSIONS: The results suggest that in young adults, motor performance may be influenced by precuing or priming the brain with performance-related words. A meaning of a motor performance can be manipulated by contextually relevant language, which can facilitate performance.

Personal preference and quality of reach in healthy adult women.

OBJECTIVE: A common practice in occupational therapy is to have clients choose an object that they prefer to be used during treatment. This practice assumes that a preference for chosen items will hold greater meaning and result in higher quality of movement. Little research has been conducted that specifically addresses the effect that preference has on quality of movement. Therefore, the purpose of this study was to contribute to the knowledge by determining whether preference affects quality of movement. METHOD: Forty-three healthy right-hand-dominant adult women between the ages of 18 and 60 years in Northwest Ohio engaged in this study. Each participant rank-ordered 15 magazines from most preferred to least preferred. The participant then reached for her most preferred, neutrally preferred, and least preferred magazines. RESULTS: When participants reached for the neutrally preferred magazines, movement time was significantly slower and movement units were significantly greater (less smooth) than when they reached for a magazine perceived as being the least preferred (p < .017). No differences were found between the three conditions in terms of displacement, peak velocity, or percentage of time to peak velocity, nor between the most preferred and the other two preferences. CONCLUSION: This study has shown that preference may not be an influential factor when performing simple reaches for magazines. Although there was a difference between the neutrally preferred and least preferred conditions, the goal when reaching during the neutrally preferred condition may have been different (i.e., to glean more information from the magazine cover) than when reaching in the least preferred condition (e.g., to reach for and discard the magazine as quickly as possible). These results reflect the complexity involved in the formation of meaning, of which preference is a part. Further exploration of individual preferences as well as personal goal formation and their impact on success in occupations of daily living is needed.