Measuring posture change to detect emotional conditions for workers: A scoping review.

BACKGROUND: The emotional management of workers can not only increase the efficiency of work, but also contribute to the improvement of the productivity of a company. OBJECTIVE: This scoping review surveyed the literature to identify the relationship between postural expression and emotion during sedentary tasks. METHODS: We searched relevant literature published up to December 1, 2019 using seven electronic databases (PubMed, CINAHL, Embase, Web of Science, PsycINFO, IEEE Xplore, and MEDLINE Complete). RESULTS: A total of 14 publications were included in this scoping review. It was found that the application of pressure sensor and camera-based measurement equipment was effective. Additionally, it was proposed to predict the emotional state of the worker by using forward and backward movements as the main variable as opposed to left and right movements. The information-based analysis technique was able to further increase the accuracy of workers' emotion prediction. CONCLUSIONS: The emotion prediction of workers based on sitting posture could be confirmed for certain movements, and the information-based technical method could further increase the accuracy of prediction. Expansion of information-based technical research will further increase the possibility of predicting the emotions of workers based on posture, and this will in turn promote safer and more efficient work performance.

Measuring emotional variables in occupational performance: A scoping review.

BACKGROUND: As interest in job-related psychology increased, the need to focus on understanding workplace stress was emphasized. Negative emotional states such as anxiety and stress permeate the organization and, if uncontrolled, can negatively impact the health and work performance of workers. Therefore, attempts to analyze various signals to understand human emotional states or attitudes may be important for future technological development. OBJECTIVE: The purpose of this study was to identify what biological variables can discriminate emotions that can significantly affect work results. METHODS: Databases (Embase, PsychINFO, PubMed, and CINAHL) were searched for all relevant literature published as of December 31, 2019. RESULTS: Brain activity (BA) and heart rate (HR) or heart rate variability (HRV) are adequate for assessing negative emotions, while BA, galvanic skin response (GSR), and salivary samples (SS) can confirm positive and negative emotions. CONCLUSION: In the future, researchers should study measurement tools and bio-related variables while workers perform tasks and develop intervention strategies to address emotions associated with work. This may enable workers to perform tasks more efficiently, prevent accidents, and satisfy clients.

A study on effects of backrest thickness on the upper arm and trunk muscle load during wheelchair propulsion.

[Purpose] The purpose of this study was to investigate the effects of the thickness of a wheelchair backrest provided for support and comfort on upper arm and trunk muscle load during wheelchair propulsion by using accelerometers. [Subjects and Methods] The Fourteen healthy participants were enrolled in this study. The study compared effects of three backrest conditions including no pad, a 3-cm-thick lumbar pad, and a 6-cm-thick lumbar pad. The instruments used for measurement were used two accelerometers. The participants were asked to propel their wheelchairs, which had been equipped with two accelerometers, 30 times. [Results] The intensity of muscle movement with the 3-cm-thick lumbar pad was significantly lower than the intensities with no lumbar pad and the 6-cm-thick lumbar pad. The muscle intensity did not differ significantly between the no pad and 6-cm-thick lumbar pad conditions. [Conclusion] An appropriately thick backrest has good effects on upper arm and trunk muscles during wheelchair propulsion. In the future, we must consider the appropriate backrest thickness for providing wheelchair users with a comfortable wheelchair.

Effects of different lifting and lowering heights on upper arm, shoulder and back muscle activity during a manual material handling task.

BACKGROUND: Previous research has suggested eliminating certain types of manual material handling (MMH) work by recommending specific arm angles and postures to avoid, such as arm flexion or abduction over 90°. MMH with arm flexion over 90° can require lifting objects as well as lowering objects. However, few studies have evaluated MMH work while lowering objects in detail. OBJECTIVE: This study investigated the effects of different lifting and lowering heights on upper arm, shoulder, and back muscle activity during a MMH task. METHODS: The participants performed a MMH task that involved stoop lowering and lifting. The participants transferred the box to shelves positioned 30  cm in front of them under various conditions. Conditions 1 to 4 involved transferring the box to 1) ankle-, 2) knee-, 3) waist-, and 4) shoulder-high shelves, respectively. Surface electrodes were attached to the biceps brachii, upper trapezius, rhomboid minor, and L4 erector spinae. RESULTS: The activity of the biceps brachii was decreased significantly in Conditions 1 and 2 compared to Conditions 3 and 4. The upper trapezius activity was increased significantly in Conditions 1 and 4 compared to Conditions 2 and 3. The rhomboid minor activity increased significantly in Condition 1 compared to Conditions 2 to 4. The L4 erector spinae activity decreased significantly in Condition 1 compared to Conditions 2 to 4 CONCLUSIONS:A low-lowering MMH work could contribute to neck, shoulder, and back pain. Therefore, further studies must examine a height below-knee MMH work in detail.

Specialization in interlimb transfer between dominant and non-dominant hand skills.

[Purpose] This study aimed to confirm the specialization of interlimb transfer in occupationally embedded tasks between dominant and non-dominant hands. [Subjects] Twelve neurologically intact participants were recruited. [Methods] The participants were divided into two training groups and performed training with their dominant or non-dominant hand. Three subtests of the Jebsen-Taylor Hand Function Test were used to practice interlimb transfer training in each group. All Jebsen-Taylor Hand Function Test subtests were evaluated using the untrained hand before and after 5 days of training. [Results] The dominant hand group showed significant differences after training when using the untrained hand in the simulated feeding and lifting large heavy objects subtests. Meanwhile, the non-dominant hand group showed significant differences after training when using the untrained hand in the turning cards, simulated feeding, stacking checkers, and lifting large heavy objects subtests. [Conclusion] When performing occupationally embedded tasks, the dominant hand has interlimb transfer advantages with respect to predictable dynamic movements, while the non-dominant hand has interlimb transfer advantages in stabilization.

The effects of backrest thickness on the shoulder muscle load during wheelchair propulsion.

[Purpose] This study investigated the optimal thickness of the wheelchair backrest for lumbar load and increased comfort. [Subjects] Fifteen healthy people participated. [Methods] The study examined three randomized backrest conditions: no pad; a 3-cm-thick lumbar pad; and a 6-cm-thick lumbar pad. The location of the lumbar pad was standardized at the mid-lumbar level (L3). Participants were instructed to propel the wheelchair using only the handrims. [Results] Activation of the anterior deltoid, upper trapezius, and biceps brachii muscles was significantly reduced when the participants used the 3-cm pad compared to no pad, while it was significantly increased in the anterior deltoid, upper trapezius, posterior deltoid, and biceps brachii when the participants used the 6-cm pad compared to the 3-cm pad. Muscle activation did not differ significantly between the no pad and the 6-cm lumbar pad conditions. [Conclusion] A lumbar pad decreased the activation of the upper extremity muscles. We believe that padding of the appropriate thickness will lead to effective muscle activation while propelling a wheelchair and decrease the risk of musculoskeletal disease.

Effects of chewing gum on driving performance as evaluated by the STISIM driving simulator.

[Purpose] The purpose of this study was to determine the effects of chewing gum on driving performance in a driving simulator. [Subjects] In total, 26 young licensed drivers participated. [Methods] The driving scenario was typical of an urban environment: a single-carriageway, two-way road consisting of a mix of curved and straight sections, with considerable levels of traffic, pedestrians, and parked cars. Mean distance driven above the speed limit, lane position, mean distance driven across the center line, and mean distance driven off the road were used as estimates of brake, accelerator, and steering control. The results were compared with those of a non-chewing gum control condition. [Results] The driving performance while chewing gum was significantly better: the mean distance driven above the speed limit was 26.61% shorter, and the mean distance driven off the road was 31.99% shorter. Lane position and mean distance driven across the center line did not differ significantly between the two conditions. [Conclusion] Chewing gum appears to enhance driving performance during a sustained attention driving task.

Relationships of stroke patients' gait parameters with fear of falling.

[Purpose] The purpose of this study was to assess the correlation of gait parameters with fear of falling in stroke survivors. [Subjects] In total, 12 patients with stroke participated. [Methods] The subjects performed on a Biodex Gait Trainer 2 for 5 min to evaluate characteristic gait parameters. The kinematic gait parameters measured were gait speed, step cycle, step length, and time on each foot (step symmetry). All the subjects also completed a fall anxiety survey. [Results] Correlations between gait parameters and fear of falling scores were calculated. There was a moderate degree of correlation between fear of falling scores and the step cycle item of gait parameters. [Conclusions] According to our results, the step cycle gait parameter may be related to increased fall anxiety.

A comparison of hemisphere-specific training pattern in Inter-limb Learning Transfer (ILT) for stroke patients with hemiparesis.

BACKGROUND: Stroke patients have major problems with impaired upper-extremity function. Unfortunately, many patients do not experience a full recovery from movement deficits in the upper extremities. OBJECTIVES: The purpose of this study was to compare the effectiveness of inter-limb learning transfer (ILT) to the contralateral upper limb after both hemisphere-specific and -unspecific ipsilateral upper limb training for stroke patients with hemiparesis. METHODS: Twenty-four stroke patients with hemiparesis participated. The hemisphere-specific training group performed reaching movements in a customized training setting in which non-dominant limb training participants began from a single starting location and proceeded to one of three target locations (1S3T condition); the dominant limb training participants started from one of three starting locations and proceeded to a single target location (3S1T condition). The hemisphere-unspecific training group performed these movements starting under reverse-start and target conditions. RESULTS: The non-dominant to dominant limb transfer, the hemisphere-specific training group performance time decreased significantly as compared with the pre-training session (p < 0.05). Also, the isolation contraction ratio was decreased significantly from that of the pre-training session in the biceps brachii muscles and increased significantly in the upper trapezius muscles (p < 0.05). And, dominant to non-dominant limb transfer in the hemisphere-specific training group significantly increased RMS amplitudes from the pre-training session in the biceps brachii and triceps muscles (p < 0.05). Also, the isolation contraction ratio was increased significantly from that of the pre-training session in the biceps brachii muscles and decreased significantly in the upper trapezius muscles (p < 0.05). However, the hemisphere-unspecific training group showed no significant differences in inter-limb learning transfer (ILT). CONCLUSION: The transfer of hemisphere-specific training from one arm to the other had a more positive influence on functional recovery than did hemisphere-unspecific training for patients with stroke and hemiparesis.

The Effect of a New Neck Support Tying Method Using Thera-Band on Cervical ROM and Shoulder Muscle Pain after Overhead Work.

[Purpose] This study proposed a new neck support tying (NST) method using Thera-Band for the prevention of neck and shoulder pain in workers doing overhead work. The purpose of this study was to investigate the effect of the new NST method using Thera-Band on cervical ROM and shoulder pain after overhead work. [Subjects] Fourteen male subjects were recruited. [Methods] This study measured the cervical ROM and pressure pain threshold (PPT) of the upper and middle trapezius (UT and MT) muscles after the control and NST groups had performed overhead work. [Results] The cervical flexion, extension, and lateral flexion angles of the NST group were significantly larger than those of the control group. The PPTs of UT and MT of the NST group were significantly higher than those of the control group [Conclusion] The NST prevented ROM reduction and pain in the cervical and shoulder regions.

Effect of specialized task training of each hemisphere on interlimb transfer in individuals with hemiparesis.

BACKGROUND: Therapeutic concept of interlimb transfer provides very important information relevant to patients with stroke because it can be applied to help these patients recover movement skills disrupted following unilateral damage to the brain. OBJECTIVES: The purpose of this study was to determine the transfer effects for both specialized training in each hemisphere and reversed training of a specialized task. METHODS: Twenty patients (ten women and ten men) with stroke and hemiparesis participated. All participants were in Brunnstrom recovery stage five or higher for arm and hand function and had Mini-Mental State Examination scores ≥25. We used a training task involving a modified static cone, modified box and block, and modified pegboard tasks. The specified-training group performed the reaching movements (based on grip, reach, and release movements) in a modified training setting in which left-handed participants began from a single starting location and proceeded to one of three target locations (1S3T condition), and the right-handed participants started form one of three starting locations and proceeded to a single target location (3S1T condition). The unspecified training group performed these movements starting under reverse-start and target conditions. RESULTS: As a result of the left-to-right limb transfer in the specified-training group differed significantly in duration from that in the pre-training group. Also, the biceps brachii and triceps (lateral head) muscles were significantly more active after performing the specified training than before. On the other hand, the activity of the upper trapezius muscle did not significantly differ after specified training compared with before training. CONCLUSION: Consequently, a symmetric transfer advantage was observed that depended on the characteristic resources of each hemisphere. The transfer of specified training from one arm to the other had a more positive influence on functional recovery than did unspecified training for patients with stroke and hemiparesis.

Neck and shoulder muscle activation in farm workers performing simulated orchard work with and without neck support.

OBJECTIVE: The purpose of this study was to detect any differences in electromyographic (EMG) activity in the neck and shoulder muscles while performing simulated orchard work with and without neck support. PARTICIPANTS: Fourteen healthy orchard harvesters (eight men and six women) who had no functional disorder of the neck or upper limbs and had never received orthopedic surgery were recruited. METHODS: A repeated-measures design was used. The subjects were asked to perform simulated orchard work with and without neck support. The EMG activities of the anterior deltoid, middle deltoid, upper trapezius, and triceps brachii (lateral head) muscles during the two conditions were analyzed using paired t-tests. RESULTS: The EMG activity of the anterior deltoid and middle deltoid muscles increased significantly and that of the upper trapezius muscles decreased significantly when the working with a neck support compared to without it (p < 0.05). Wearing a neck support may prevent overuse of the upper trapezius muscles by encouraging shoulder elevation and activating the deltoid muscles. The activation of these muscles decreases scapular movement and the results in greater stabilization of scapulohumeral rhythm. CONCLUSIONS: The appropriate application of a neck support may be helpful in preventing disorders of the neck and shoulder muscles resulting from long-term intensive orchard work, however long term application of such support is necessary before definitive information is available.

Effects of wearing the wrong glove size on shoulder and forearm muscle activities during simulated assembly work.

This study was performed to determine the changes in electromyographic activities in the shoulder and forearm muscles when using the bare hands, well-fitting gloves, and gloves that are one size smaller or one size larger for simulated assembly operations. Sixteen asymptomatic seated workers with normal hands and no obvious deformities, skin diseases, or allergies were recruited. The subjects were asked to simulate assembly operations using their bare hands, well-fitting gloves, and one size smaller or one size larger. This study showed that wearing the wrong glove size led to a decrease in forceful activation of the forearm muscle and a compensatory increase in shoulder movement. In contrast, use of the bare hands or wearing well-fitting gloves led to effective forearm muscle activation, which decreased inefficient shoulder movement. These data indicate that wearing the wrong glove size will lead to continuous inefficient use of the forearm and shoulder muscles, and result in overuse of the shoulder.

Effects of wearing a tight necktie on cervical range of motion and upper trapezius muscle activity during computer work.

OBJECTIVE: This study examined the effects of wearing a tight necktie on cervical range of motion and upper trapezius muscle activity. METHODS AND PARTICIPANTS: Thirty computer workers were recruited. First, the active cervical ROM of the participants while wearing or not wearing a tight necktie was measured using the CROM instrument. Subsequently, upper trapezius muscle activity was measured while working at a visual display terminal with and without a tight necktie. RESULTS: The neck flexion, neck extension, and lateral flexion of the subjects' cervical range of motion were significantly decreased when wearing a tight necktie compared to without it. The activity of the upper trapezius muscle significantly increased when working while wearing a tight necktie compared to without. CONCLUSION: It is especially important for male workers to select and tie neckties appropriately in order to prevent musculoskeletal injuries induced by limitation of cervical ROM or repetitive cumulative tension increase of the upper trapezius.

Effects of a multidisciplinary supervised exercise program on motor performance and quality of life in community-dwelling chronic stroke survivors in Korean.

Studies of strengthening and physical conditioning rehabilitation programs on stroke survivors have shown an increase in their physical function and quality of life (QOL). In this study the effectiveness of two exercise regimens was assessed: 1) a 24-week multidisciplinary supervised exercise program and 2) a 24-week self-monitored conditioning exercise program. Twenty-eight subjects (17 men and 11 women) were allocated to take part in either a multidisciplinary supervised program or a self-monitored exercise program. The primary outcomes were the results of the Wolf Motor Function Test (Korean version), Motor Activity Log (Korean version) and Stroke Short Form--Quality of Life assessment (Korean version). Both groups showed improvement in motor capacity and quality of life, but the improvements achieved by the multidisciplinary supervised group were greater than those of the self-monitored group. A multidisciplinary supervised program was more effective than a self-monitored program for stroke rehabilitation.

Effects of wrist-extension orthosis on shoulder and scapular muscle activities during simulated assembly tasks.

The purpose of this study was to observe changes in electromyographic activity appeared in shoulder and scapular muscles when one wears no wrist extension orthosis, short wrist extension orthosis and long wrist extension orthosis when performing two model assembling operations. The study subjects were 16 adults who use right hand and did not have any functional disorder on their wrist or the upper limbs without any orthopedic surgery. The study subjects were asked to do the two model assembling operations without wrist extension orthosis, with a short wrist extension orthosis and with a long wrist extension orthosis. As a result of repetitive assembling operation that requires shoulder movement, electromyographic activity in upper trapezius and serratus anterior increased significantly when the subjects wore the short and long wrist extension orthoses compared to none. When the subjects performed repetitive assembling operation that requires shoulder stability, electromyographic activity in upper trapezius, lower trapezius, serratus anterior, and anterior deltoid showed significant increase when they wore the short and long wrist extension orthoses compared to none. Especially, the upper trapezius showed significantly high electromyographic activity when they wore the long wrist extension orthosis compared to a short one.