The effect of types of sensory feedback on the acquisition and retention of squat performance: A randomized, double-blind, controlled trial.

Various sensory feedback methods are considered important for motor learning, but the effect of each sensory feedback method on effective squat learning still needs to be clarified. This study aimed to investigate the effect of sensory feedback types on the acquisition and retention of a squat. A double-blinded, randomized controlled trial was carried out. Thirty-healthy people were recruited and randomly assigned to the visual feedback group (VFG = 10), tactile feedback group (TFG = 10), and control group (CG = 10). VFG received visual feedback through video data of the participant performing squats, and TFG received tactile feedback through manual contact with a physical therapist. Both groups received feedback on the movements that needed correction after each set was completed. CG maintained rest without receiving any feedback. The retro-reflexive marker, force plate, and electromyography were used to measure body angle, foot center of pressure (COP), and muscle activity. All assessments were measured to confirm a squat acquisition. VFG and TFG showed significant differences in neutral knee position (NKP), trunk forward lean (TFL), anterior knee displacement (AKD), and anteroposterior (AP) foot COP (p < 0.050). In addition, the acquisition was retained until 3 days later for NKP and a week later for TFL, AKD, and AP foot COP in VFG (p < 0.050), while the acquisition was not retained in TFG (p > 0.050). There was no statistically significant change in CG (p > 0.050). This study demonstrated that visual feedback positively affects the acquisition and retention of squats. Therefore, we recommend the use of visual feedback for squat acquisition and retention in exercise novices.

Effects of dual-task resistance exercise on cognition, mood, depression, functional fitness, and activities of daily living in older adults with cognitive impairment: a single-blinded, randomized controlled trial.

BACKGROUND: Regular exercise is emphasized for the improvement of functional capacity and independence of older adults. This study aimed to compare the effects of a dual-task resistance exercise program and resistance exercise on cognition, mood, depression, physical function, and activities of daily living (ADL) in older adults with cognitive impairment. METHODS: A total of 44 older adults participated in the study. Participants were randomly allocated to an experimental group (n = 22) performing a dual-task resistance exercise program for cognitive function improvement and a control group (n = 22) performing a resistance exercise program. Both groups performed the exercise for 40 min per session, three times a week, for 6 weeks (18 sessions). Cognition, mood, depression, functional fitness, and ADL were quantified before and after the intervention using the Mini-Mental State Examination (MMSE), profile of mood states (POMS), geriatric depression scale (GDS), senior fitness test (SFT), and Korean version of ADL, respectively. RESULTS: There was a significant time and group interaction on the MMSE (p = 0.044). There were no significant time and group interactions in the POMS, GDS, SFT, or ADL. Cognitive function (p < 0.001), mood (p < 0.001), depression (p < 0.001), functional fitness (p < 0.001), and ADL (p < 0.001) significantly improved after dual-task resistance exercise, and cognitive function (p < 0.001), mood (p < 0.001), depression (p < 0.001), functional fitness (p < 0.001), and ADL (p < 0.001) significantly improved after resistance exercise. CONCLUSIONS: Dual-task resistance exercise is more effective than resistance exercise in improving cognitive function in older adults with cognitive impairment. Both dual-task resistance exercise and resistance exercise improves mood, depression, functional fitness, and ADL after the intervention. We propose using dual-task resistance exercises for cognitive and physical health management in the older adults with cognitive impairment. TRIAL REGISTRATION: This study was registered with the Clinical Research Information Service (WHO International Clinical Trials Registry Platform) (Registration ID, KCT0005389; Registration date, 09/09/2020).

Reduction of Edema and Pain in Transcutaneous Electrical Nerve Stimulation Treated-Arthritic Rat.

Transcutaneous electrical nerve stimulation (TENS) has been used to reduce pain or improve motor function in musculoskeletal and neurological disorders in the clinic. Although some studies have suggested electrotherapy as an intervention for edema, the effects and mechanisms of TENS on inflammation-induced edema remain unclear. Thus, we aimed to investigate the effects of TENS on arthritic pain with edema. 1% carrageenan was injected into the right tibiofemoral joint of 69 male Sprague-Dawley rats (200-250 g). After the development of arthritic pain, low-frequency (4-Hz, Low-TENS, n = 25) and high-frequency (100-Hz, High-TENS, n = 25) TENS with sub-motor threshold or placebo-TENS (n = 19) was applied for 20-min to medio-lateral part of the ipsilateral side. Weight bearing and knee-bend tests were used to assess pain-like behaviors. Also, we examined the size of edema and measured tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) levels in the synovium by western blot. Eight rats in each of the two TENS groups were injected with Naloxone. Edema was reduced in the low- and high-frequency TENS groups at 6-h. TENS-treated rats showed reduced pain in the knee-bend test at 6-h. We observed decreased weight load shifts on the ipsilateral side in TENS groups. Naloxone reduced these effects. TNF-α and IL-1ß expression decreased in the synovial membrane at 6-h. These results suggest that low- and high-frequency TENS have acutely positive effects on inflammatory edema, with the management of arthritic pain and reduction in pro-inflammatory mediators. Therefore, Low-TENS and High-TENS may be useful in treating acute inflammatory pain and edema.

Microneedle Array Electrode-Based Wearable EMG System for Detection of Driver Drowsiness through Steering Wheel Grip.

Driver drowsiness is a major cause of fatal accidents throughout the world. Recently, some studies have investigated steering wheel grip force-based alternative methods for detecting driver drowsiness. In this study, a driver drowsiness detection system was developed by investigating the electromyography (EMG) signal of the muscles involved in steering wheel grip during driving. The EMG signal was measured from the forearm position of the driver during a one-hour interactive driving task. Additionally, the participant's drowsiness level was also measured to investigate the relationship between muscle activity and driver's drowsiness level. Frequency domain analysis was performed using the short-time Fourier transform (STFT) and spectrogram to assess the frequency response of the resultant signal. An EMG signal magnitude-based driver drowsiness detection and alertness algorithm is also proposed. The algorithm detects weak muscle activity by detecting the fall in EMG signal magnitude due to an increase in driver drowsiness. The previously presented microneedle electrode (MNE) was used to acquire the EMG signal and compared with the signal obtained using silver-silver chloride (Ag/AgCl) wet electrodes. The results indicated that during the driving task, participants' drowsiness level increased while the activity of the muscles involved in steering wheel grip decreased concurrently over time. Frequency domain analysis showed that the frequency components shifted from the high to low-frequency spectrum during the one-hour driving task. The proposed algorithm showed good performance for the detection of low muscle activity in real time. MNE showed highly comparable results with dry Ag/AgCl electrodes, which confirm its use for EMG signal monitoring. The overall results indicate that the presented method has good potential to be used as a driver's drowsiness detection and alertness system.

Therapeutic Effect of BDNF-Overexpressing Human Neural Stem Cells (F3.BDNF) in a Contusion Model of Spinal Cord Injury in Rats.

The most common type of spinal cord injury is the contusion of the spinal cord, which causes progressive secondary tissue degeneration. In this study, we applied genetically modified human neural stem cells overexpressing BDNF (brain-derived neurotrophic factor) (F3.BDNF) to determine whether they can promote functional recovery in the spinal cord injury (SCI) model in rats. We transplanted F3.BDNF cells via intrathecal catheter delivery after a contusion of the thoracic spinal cord and found that they were migrated toward the injured spinal cord area by MR imaging. Transplanted F3.BDNF cells expressed neural lineage markers, such as NeuN, MBP, and GFAP and were functionally connected to the host neurons. The F3.BDNF-transplanted rats exhibited significantly improved locomotor functions compared with the sham group. This functional recovery was accompanied by an increased volume of spared myelination and decreased area of cystic cavity in the F3.BDNF group. We also observed that the F3.BDNF-transplanted rats showed reduced numbers of Iba1- and iNOS-positive inflammatory cells as well as GFAP-positive astrocytes. These results strongly suggest the transplantation of F3.BDNF cells can modulate inflammatory cells and glia activation and also improve the hyperalgesia following SCI.

Brain activity during a working memory task in different postures: an EEG study.

While working is more comfortable in a supine position and healthier in a standing, most people work in a sitting. However, it is unclear whether there are differences in brain activity efficiency in different postures. Here, we, therefore, compared changes in brain activity across three different postures to determine the optimal posture for performing working memory tasks. Their effect on brain activity was examined using EEG signals together with the information of accuracy and reaction times during 2-back task in 24 subjects. Substantial differences in brain waves were observed at sitting and standing positions compared to the supine, especially in delta waves and frontal lobe, where is known to improve the modulation of brain activity efficiently. Brain efficiency was higher during standing and sitting than in a supine. These findings show that postural changes may affect the efficiency of brain activity during working memory tasks. Practitioner summary: Differences in brain efficiency between different postures during working memory tasks have not been explored. This study suggests that efficiency in several brain areas is higher during sitting and standing than in a supine position. This finding has important implications regarding workplace environments. Furthermore, this result would be useful to improve accomplishment and reduce negative effects of work posture. Abbreviations: EEG: electroencephalogram; PSQI: Pittsburgh sleep quality index; KSS: Karolinska sleepiness scale; FFT: fast fourier transform; ROI: region of interest; ANS: autonomic nervous system; Fp: prefrontal; AF: anterior frontal; frontal; Fz: midline frontal; temporal; central; Cz: midline central; P: parietal; Pz: midline parietal; O: occipital; Oz: midline occipital.

Effects of Prolonged Sitting with Slumped Posture on Trunk Muscular Fatigue in Adolescents with and without Chronic Lower Back Pain.

Background and Objectives: This study investigated the effects of prolonged sitting on trunk muscular fatigue and discomfort in participants with and without chronic lower back pain (LBP). Material and Methods: This study included 15 patients with LBP and 15 healthy controls. All participants were instructed to sit on a height-adjustable chair with their knee and hip joints bent at 90° for 30 min, in slumped sitting postures. Surface electromyography was used to assess the median frequency of the internal obliques (IO)/transversus abdominis (TrA) and multifidus (MF) muscles. Perceived discomfort was measured using a Borg category ratio-scale. Median frequency of the trunk muscles and perceived discomfort after 30 min of sitting were compared with baseline. Result: There were no significant differences within the group and between both groups in the median frequency of bilateral IO and MF muscles. The LBP group showed significantly greater perceived discomfort after prolonged sitting, as compared to the control group. Conclusions: Prolonged sitting with slumped posture could increase the risk of experiencing lower back discomfort.

Apoptotic changes in a full-lengthened immobilization model of rat soleus muscle.

INTRODUCTION: Lengthened immobilization may prevent muscle shortening, and help maintain normal muscle length. However, its apoptotic effects remain unclear. We evaluated the effects of long-term immobilization on apoptotic proteins. METHODS: Rat soleus muscles were immobilized by casting in a neutral (NEUT) or lengthened (LENG) position for 21 days. We evaluated dynamic weight load and muscle atrophy following the 21-day period using hematoxylin and eosin staining. We measured Bax (pro-apoptotic Bcl-2 family member), MyoD (myogenic differentiation factor D), MYH (myosin heavy chain), and cleaved poly(ADP-ribose)polymerase levels and examined apoptotic nucleus expression. RESULTS: Decreased dynamic weight load and muscle atrophy changes were observed in LENG. Both NEUT and LENG showed significantly reduced levels of MYH. LENG showed a significant increase in Bax and MyoD expression as well as in the number of apoptotic nuclei. CONCLUSIONS: Long-term lengthened immobilization may increase apoptotic changes and decrease muscle formation proteins in muscle. Muscle Nerve 59:263-269, 2019.

The reliability and validity of the Korean version of the lower limb functional index.

[Purpose] The purpose of this study was to establish the reliability and validity of the Korean-translated version of the Lower Limb Functional Index (LLFI) in the assessment of patients with lower-limb disorders. [Subjects and Methods] Fifty-six subjects with lower-limb disorders, 24 men and 32 women, participated in this study. Reliability was determined by using the intra-class correlation coefficient and Cronbach's α for internal consistency. Validity was examined by correlating the LLFI scores with the Lower Extremity Functional Scale (LEFS) and Short Form 36 (SF-36) scores. [Results] The test-retest reliability was 0.95. The criterion-related validity was established through a comparison with the Korean versions of the LEFS and SF-36. [Conclusion] The Korean version of the LLFI was shown to be a reliable and valid instrument for assessing lower-limb complaints.

Effects of chin tuck exercise using neckline slimmer device on suprahyoid and sternocleidomastoid muscle activation in healthy adults.

[Purpose] This study investigated the effect of chin tuck exercise (CTE) using a neckline slimmer device on suprahyoid (SH) and sternocleidomastoid (SCM) muscle activation in healthy adults. [Subjects and Methods] We measured activation of the SH and SCM muscles using surface electromyography in 20 healthy adults during head lift exercise (HLE) and CTE using a neckline slimmer device. The order of exercises was randomized and the mean and peak values of each muscle's activation were assessed. [Results] During the CTE using a neckline slimmer device, SH activation was significantly greater and SCM activation was significantly lower than during the HLE. [Conclusion] This study suggest that chin-tuck exercise using a neckline slimmer device may be more helpful than HLE for swallowing training.

Effects of lumbar lordosis assistive support on craniovertebral angle and mechanical properties of the upper trapezius muscle in subjects with forward head posture.

[Purpose] The aim of this study was to investigate the effect of lumbar lordosis assistive support (LLAS) on craniovertebral angle (CVA) and mechanical properties of the upper trapezius (UT) muscle in subjects with forward head posture (FHP). [Subjects and Methods] This study recruited 20 subjects with FHP. CVA and muscle tone, viscoelasticity, and stiffness of the UT were measured using Myoton in all subjects in a sitting position with LLAS and in a neutral sitting position. The order of measurements was randomized and the mean values were calculated twice. [Results] The sitting position with LLAS showed a significantly greater improvement than the neutral sitting position with regard to CVA and muscle tone, viscoelasticity, and stiffness of the UT. [Conclusion] We suggest that the sitting position using LLAS induces the maintenance of normal neck posture and a reduction in the muscle tone of the UT in the subjects with FHP.

Effect of a cervical support pillow on sternocleidomastoid activity and satisfaction in asymptomatic participants.

[Purpose] The aim of this study was to examine the changes in sternocleidomastoid muscle (SCM) activity when using a cervical support pillow (CSP) and to determine the pillow's effect on satisfaction in asymptomatic participants. [Subjects and Methods] This study followed a cross-over design and the order of the measurements was counterbalanced. Twenty asymptomatic participants were positioned supine for 5 minutes by using either a CSP or a general pillow (GP) while the activity of the SCM was measured using surface electromyography. [Results] The CSP significantly decreased the activity of the SCM compared with the GP, and satisfaction after use of the CSP was significantly greater than that after use of the GP. [Conclusion] This study suggests that the CSP may be effective in preventing unnecessary neck muscle activation during sleep in asymptomatic people.

Effects of expiratory muscle strength training on swallowing function in acute stroke patients with dysphagia.

[Purpose] This study was conducted to identify the effects of expiratory muscle strength training on swallowing function in acute stroke patients with dysphagia. [Subjects and Methods] A total of 18 stroke patients with dysphagia were enrolled in the study. All participants were randomly assigned to either an experimental group (n=9) or a control group (n=9). All participants performed traditional-swallowing rehabilitation therapy in 30-minute sessions five times a week for four weeks; however, only the experimental group received expiratory muscle strength training. [Results] Both groups showed significant improvements after mediation. When compared with the control group, the functional dysphagia scale, vallecular residue, and penetration-aspiration scale were significantly improved in the experimental group. [Conclusion] Expiratory muscle strength training is an effective intervention for impaired swallowing function in acute strike patients with dysphagia.

Immediate effects of Graston Technique on hamstring muscle extensibility and pain intensity in patients with nonspecific low back pain.

[Purpose] The purpose of this study was to analyze the effect of Graston Technique on hamstring extensibility and pain intensity in patients with nonspecific low back pain. [Subjects and Methods] Twenty-four patients with nonspecific low back pain (27-46 years of age) enrolled in the study. All participants were randomly assigned to one of two groups: Graston technique group (n=12) and a static stretching group (n=12). The Graston Technique was used on the hamstring muscles of the experimental group, while the static stretching group performed static stretching. Hamstring extensibility was recorded using the sit and reach test, and a visual analog scale was used to measure pain intensity. [Results] Both groups showed a significant improvement after intervention. In comparison to the static stretching group, the Graston technique group had significantly more improvement in hamstring extensibility. [Conclusion] The Graston Technique is a simple and effective intervention in nonspecific low back pain patients to improve hamstring extensibility and lower pain intensity, and it would be beneficial in clinical practice.

The effects of task-oriented training on hand dexterity and strength in children with spastic hemiplegic cerebral palsy: a preliminary study.

[Purpose] The purpose of this study was to investigate the effects of task-oriented training (TOT) on hand dexterity and strength in children with spastic hemiplegic cerebral palsy. [Subjects and Methods] Twelve children with spastic hemiplegic cerebral palsy were randomly assigned to either the TOT group (n=6) or the control group (n=6). In both groups, conventional occupational therapy was performed 40-min/day, 2 times a week, for 4 weeks. In the TOT group, TOT was additionally performed for 20 min, and the control group received usual care. The box and block test (BBT) was performed to assess hand dexterity. Hand strength was also assessed using hand dynamometer. [Results] After intervention, the TOT group showed a significant improvement of hand dexterity. In the control group, BBT and grip strength were not significantly improved after intervention. [Conclusion] In clinical settings, we suggest that TOT may be used as an intervention to improve hand dexterity in children with spastic hemiplegic cerebral palsy.

The reliability and validity of the Korean version of the foot function index for patients with foot complaints.

[Purpose] The purpose of this study was to establish the reliability and validity of the Foot Function Index translated into Korean for use in patients with plantar fasciitis and foot/ankle fracture. [Subjects and Methods] Thirty-six subjects with foot complaints, 14 males and 22 females, participated in the study. Reliability was determined by using the intra-class correlation coefficient and Cronbach's alpha for internal consistency. Validity was examined by correlating Foot Function Index scores with the Short Form-36 and the Visual Analog Scale scores. [Results] Test-retest reliability was 0.90 for the pain subscale, and 0.94 and 0.91 for the disability and activity limitation subscales, respectively. The criterion-related validity was established by comparison with the Korean version of the Short Form-36 and Visual Analog Scale. [Conclusion] The Korean version of the Foot Function Index was shown to be a reliable and valid instrument for assessing foot complaints.

The reliability and validity of the Korean version of the Upper Limb Functional Index.

[Purpose] The purpose of this study was to establish the reliability and validity of Upper Limb Functional Index (ULFI), which has been translated into Korean, in treating patients with upper limb complaints. [Subjects and Methods] Fourty-nine subjects with upper limb disorder, 20 males and 29 females, participated in this study. Reliability was determined by using the intra class correlation coefficient and Cronbach's alpha for internal consistency. Validity was examined by correlating ULFI scores with Disability of Arm, Shoulder and Hand (DASH). [Results] Test-retest reliability was 0.90. The criterion-related validity was established by a comparison with the Korean version of DASH. [Conclusion] The Korean version of ULFI was shown to be a reliable and valid instrument for assessing upper limb complaints.

Effects of lingual strength training on lingual strength and articulator function in stroke patients with dysarthria.

[Purpose] This study investigated the effects of lingual strength training (LST) on lingual strength and articulator function in stroke patients with dysarthria. [Subjects and Methods] 16 stroke patients with dysarthria were randomly assigned into two groups: the experimental group (n=8) or the control group (n=8). Both groups received the conventional rehabilitation therapy at 30 min/day, 5 times for week, and during 4 weeks, and the experimental group received an additional 30 min of LST using the Iowa Oral Performance Instrument (IOPI). The Maximum Isometric Tongue Pressures (MIPs) was used to assess the lingual strength and the Alternating-Motion Rate (AMR) and Sequential-Motion Rate (SMR) were used to measure the articulator function. [Results] After the intervention, the experimental group showed a significant improvement in MIPs and AMR (/tə/) than the control group. [Conclusion] Findings of this study suggest that LST provides positive effects on lingual strength and articulator function, and thus can be used as an interventional method in stroke patients with dysarthria.

The effects of spinal support device on pain and extensibility of the hamstrings in patients with non-specific low back pain.

[Purpose] The objective of this study was to investigate the effects of spinal support device (SSD) on pain and hamstring extensibility in patients with non-specific low back pain (NSLBP). [Subjects and Methods] 20 patients with NSLBP were recruited and randomly assigned to either the SSD group or the control group. In the SSD group, SSD was applied; in the control group, bed rest in supine position was performed. Both groups underwent treatment 20 min/day, 3 times a week, for a duration of 4 weeks. To assess the hamstring extensibility, sit and reach test (SRT) was performed. To assess pain pressure threshold (PPT) of the sacroiliac joint, a pressure algometer was used. Visual analog scale (VAS) was used to quantify pain. [Results] The SSD group showed a significant improvement in sacroiliac joint pain with increased VAS, and the control group showed a significantly increased VAS after intervention. In the SSD group, VAS was significantly increased, but SRT was not changed compared with the control group. [Conclusion] These results demonstrated that an application of SSD effectively attenuates low back pain. Therefore, SSD may be a suitable intervention for pain control in patients with NSLBP.

Trunk exercises performed on an unstable surface improve trunk muscle activation, postural control, and gait speed in patients with stroke.

[Purpose] This study examined the effects of trunk exercises performed on an unstable surface on trunk muscle activation, postural control, and gait speed in stroke patients. [Subjects] Twenty-four participants with stroke were recruited in this study and randomly distributed into experimental (n = 12) and control groups (n = 12). [Methods] Subjects in the experimental group participated in trunk exercises on the balance pad for 30 min, five times a week for 4 weeks; those in the control group performed trunk exercises on a stable surface for 30 min, five times a week for 4 weeks. Trunk muscle activation was measured by using surface electromyography, and trunk control was evaluated with the Trunk Impairment Scale (TIS). Gait speed was measured with the 10-Meter Walk Test. [Results] Activity of the external and internal oblique muscles in the experimental group was significantly higher than that in the control group. The TIS score of the experimental group showed significantly greater improvement than did that of the control group. The 10-Meter Walk Test (10MWT) score also significantly improved in the experimental group. [Conclusion] Trunk exercises on an unstable surface improve trunk muscle activation, postural control, and gait speed in patients with hemiparetic stroke.