Biotechnology and Sports Engineering II

Results of a recent experimental study challenge the widely-held belief that modern combat helmets are more effective at protecting soldiers against concussions. The research shows that helmets used during First World War without inner paddings may have an advantage in protecting soldiers’ brains from concussions when relying solely on cerebrospinal fluid. The present study explains this counterintuitive finding by revealing that while cerebrospinal fluid can prevent direct brain-to-skull contact during a single event, its protective capabilities diminish with each subsequent event occurring in quick succession—something conventional padded helmets appear to aggravate. The cerebrospinal fluid requires a certain amount of time to reset after an acceleration/deceleration event, which allows it to effectively provide cushioning for any subsequent events and protect against potential brain damage. However, an immediate occurrence of a subsequent event, when the fluid has no time to settle down, may significantly diminish the effectiveness of the fluid’s ability to provide adequate cushioning, thereby putting individuals at risk of serious injury. This new information may have implications for helmet design in the future and calls into question current assumptions regarding the best way to protect soldiers and athletes from concussions. Full article

The current study compared the effects of exercise program and a rehabilitation exercise program (REP) with electro muscle stimulation (EMS) on participants who had anterior cruciate ligament (ACL) reconstruction. The control group (CONG, n = 12) and the electro muscle stimulation group (EMSG, n = 12) were equally assigned among the 24 patients who underwent ACL reconstruction. For 12 weeks, CONG executed the REP, and EMSG executed of added EMS into the REP. Every participant in the rehabilitative exercise program completed two 60 min sessions each week for a total of 12 weeks. Both a pre- and post-evaluation were completed before and after the workout session. IKDC (International Knee Documentation Committee) score, Lysholm score, thigh circumference, muscular activity, and isokinetic muscle function were the variables examined. The EMSG exposed a significant increase (p < 0.05) in Lysholm score, muscle circumference, muscle activity of vastus medialis (VM), rectus femoris (RM), and vastus lateralis (VL), and isokinetic function (peak torque, total work). However, CONG only showed a significant increase in IKDC score (p < 0.05). This study proved that the REP employing EMS following ACL reconstruction enhanced muscular activation during muscle contraction when compared to REP, and it showed that using EMS in rehabilitation exercise is an effective rehabilitation strategy. Full article

As the competition among businesses intensifies and customer needs become increasingly diverse and complex, the need for personalized service has emerged. This study examines the effect of technology-based self-service (TBSS) characteristics of a Taekwondo academy on perceived value and intention to use continuously. The study sample consisted of masters managing a Taekwondo academy who had prior experience with TBSS. A total of 188 responses were collected using an online questionnaire. The collected data were analyzed using SPSS 23.0 and AMOS 23.0. The results demonstrated the following: first, among the sub-factors of TBSS characteristics, reliability, usefulness, and enjoyment were found to affect the perceived value positively; second, among the sub-factors of TBSS characteristics, usefulness and ease of use positively affected the intention to use continuously; and finally, the perceived value was found to affect the intention to use continuously positively. This study provides practical implications for more efficient use of the TBSS provided by a Taekwondo academy by discovering the relationship between the TBSS configuration of the Taekwondo academy, perceived value, and intention to use continuously. Full article

The present study examined the effects of a rehabilitation exercise program with blood flow restriction (BFR) vs. a general rehabilitation exercise program in patients who have undergone anterior cruciate ligament (ACL) reconstruction. Among a total of 24 patients, the general rehabilitation exercise group (GRE, n = 12) and blood flow restriction group (BFR, n = 12) were assigned the same. The GRE group conducted a general rehabilitation exercise, and the BFR group conducted a BFR exercise along with the general rehabilitation exercise. All participants performed the rehabilitation exercise program session for 60 min three times a week for 12 weeks under supervision. All dependent parameters (Lysholm score and International Knee Documentation Committee (IKDC) subjective score, muscle activity, isokinetic muscular function, Y-balance test) were evaluated before and after the rehabilitation exercise program. GRE improved the Lysholm score, IKDC subjective score and Y balance test (posterior-medial, posterior-lateral) (p < 0.05). Moreover, BFR was effective in improving the Lysholm score and IKDC subjective score and muscle activity (e.g., vastus medialis oblique during isokinetic contraction and rectus femoris during isometric contraction), isokinetic function (e.g., peak torque and total work) and Y-balance test (e.g., anterior, posterior medial, posterior lateral) (p < 0.05). Our study confirmed that a rehabilitation exercise program with BFR after ACL reconstruction is a more effective rehabilitation modality for improving muscle activity during muscle contraction and muscle function compared with GRE. Therefore, it is recommended to use BFR as an effective rehabilitation program for rapid recovery after ACL reconstruction. Full article

Korea already entered the aging society (August 2017), in which 14% of the population is 65 years or older, and it is expected to enter as a super-aged society, in which 20% of the population is elderly at the world’s fastest rate by 2025. This means that a health management plan is needed to effectively manage the health of the elderly in preparation for the upcoming super-aging society. Therefore, this study analyzed the effects of exercise on serum osteocalcin, bone ALP, and estradiol, which are representative indicators of bone formation after six months of complex exercise, and confirmed the usefulness of exercise programs and biochemical indicators for the elderly in late years to provide basic data for the prevention of osteoporosis. The subjects of this study were the elderly in late years (exercise group = 14, control group = 15), those 75 years or older in Korea, who performed complex exercises twice a week for six months. As a result of analyzing the effect of exercise performance on osteocalcin in the elderly in late years for six months in this study, no significant difference was found. However, osteocalcin decreased by 7.7% in the control group and increased by 18.66% in the exercise group, while ALP increased by 18.92% in the control group and significantly increased by 69.81% in the exercise group. As a result of analyzing the effect on estradiol, there was no significant difference, but it decreased by 55.09% in the control group and decreased by 1.85% in the exercise group. Based on the results showing that exercise clearly plays a positive role in improving bone density even for middle- and late-aged elderly people, in the future, the exercise will be useful to maintain and improve health related to the skeleton of the elderly through the combined participation of aerobic, resistance, and balance exercises. In addition, it is necessary to conduct repeated studies targeting the elderly of various age groups to evaluate the effects of exercise according to period and gender. Full article

This study aimed to investigate the effects of exercise habits and types on the HRQOL of adults with CP, based on the fact that regular exercise habits, such as exercise, physical activity, etc., during leisure time have a positive effect on the improvement of HRQOL. A total of 215 adults (164 Men and 51 Women; 50 Gross Motor Function Classification System (GMFCS) Level I, 116 Level II, 24 Level III, and 25 Level IV) with CP but ambulant were recruited for this study. The mean (± SD) age of the subjects was 35.74 ± 9.65 years. They were evaluated using Medical Outcomes Study Short Form–36 (SF-36), the world’s most popular questionnaire for measuring health status, which is used widely in research targeting all healthy and elderly individuals with disabilities and is also used for the evaluation of HRQOL. SF-36 includes 8 subscales with 36 questions. In addition, in order to investigate further into exercise habits and types, four more detailed questions were asked: presence of exercise habits at least once a week; duration of exercise in adults who have exercise habits with CP; weekly exercise frequency; time of a single exercise session. The following are the results of the analysis of variance to confirm the difference in HRQOL depending on the presence of exercise habits in adults with CP. A significant difference was found in all items, except for the BP item, among the subscales of the HRQOL (p < 0.01), with higher values observed for those with exercise habits compared with those with no exercise habits. A significant difference was found in all items, except for BP, among the subscales of HRQOL (p < 0.01). Additionally, a positive (+) correlation was found in RP, VT, RE, MH, and MCS (p < 0.05) in terms of exercise duration in adults who have exercise habits with CP. In addition, a negative (−) correlation was found in SF, RE, and MCS (p < 0.05) in terms of the weekly exercise frequency. However, no significant correlation was found in all subscales of HRQOL in terms of the time of a single exercise session. In conclusion, it has become clear from adults with CP that engaging in regular exercise at least once a week has a positive effect on improving all subscales of HRQOL except for BP. Efforts by individuals, groups, and families all need to be made in order for adults with CP to have regular exercise habits to improve their HRQOL. Full article

The purpose of this study is to analyze the effect of lower extremity muscle strength of HIP joint and KNEE joint on the aerobic capacity to provide the basic data for developing an exercise program that can effectively improve the aerobic capacity of adults with cerebral palsy (CP) by identifying the part of the lower extremity muscle. A total of 18 ambulant adults with CP were recruited for this study. Seven ambulant adults with CP were excluded because they did not achieve the criteria of maximal exercise. The data from 11 subjects (11 men) with CP were used for the analysis. The mean (±SD) age, height, weight, and BMI of the subjects were 37.00 ± 12.72 years, 170.45 ± 6.37 cm, 67.02 ± 8.62 kg, and 23.09 ± 2.78 kg/m², respectively. To measure the muscle strength of HIP joint and KNEE joint in lower extremities, the variables of the isokinetic muscle strength and the muscular endurance were performed using the isokinetic equipment (Biodex Co., Shirley, NY, USA). For the isokinetic muscle strength measurement of HIP joint, the 45°/sprotocol indicating the muscle power and the 300°/s protocol indicating the muscle endurance were used. Additionally, the measurement of KNEE joint was performed once on the left and right side, using the protocol of 60°/s indicating the muscle power and 300°/s indicating the muscular endurance. Progressive exercise tests were conducted on the treadmill (Quinton model—4500) using previously developed protocols targeting CP. The initial protocol speeds were 5 km/h⁻¹ and 2 km/h⁻¹ for the subjects who have been classified as Gross Motor Function Classification System (GMFCS) level I and II, respectively. Using a portable cardiopulmonary indirect breath-by-breath calorimetry system (MetaMax 3B; Cortex Biophysik, Leipzig, Germany), pulmonary ventilation (VE), respiratory exchange ratio (RER), and oxygen uptake (VO₂) have been persistently measured. HR monitor (Polar Electro, Kempele, Finland polar Co. RS-800) was used to measure heart rate (HR). A correlation analysis was conducted to find out how the lower extremity muscle strength and aerobic capacity with cerebral palsy are related. Therefore, as a result, VO_2peak among aerobic capacity displayed a significant positive correlation in 45° and 300°/s peak torque/BW of HIP joint, and with 60° and 300°/s peak torque/BW of KNEE joint. It was the same with 60°/s Agon/Antag ratio of KNEE Joint (p < 0.05). VE_peak showed a significant positive correlation with 45° and 300°/s peak torque/BW of HIP joint, as well as correlation with 60° and 300°/s peak torque/BW and 60°/s Agon/Antag ratio of KNEE joint (p < 0.05). However, HRpeak showed a significant positive correlation only in 45°/s peak torque/BW of HIP joint (p < 0.05). The result of step-wise analysis was to find out which muscle strength significantly affects VO_2peak and HR_peak among aerobic abilities in the lower extremity muscles of those disabled with cerebral palsy. Among the muscle functions of lower extremity muscle strength, 300°/s peak torque/BW of KNEE Joint was found to have the greatest effect on VO_2peak (p < 0.001). As a result, 300°/s peak torque/BW of KNEE Joint was found to be the predictable factor that could explain the VO_2peak in the disabled people with cerebral palsy at 67% (R² = 0.661). In particular, among the muscle functions of lower extremity muscle strength at 45°/s peak, torque/BW of HIP Joint was found to have the greatest effect on HR_peak (p < 0.001). As a result, this factor was found to be the predictable factor that could explain the HR_peak in disabled people with cerebral palsy at 39% (R² = 0.392). In this study, the muscle strength of the lower extremity of CP was closely related to the aerobic capacity, and the muscle endurance of KNEE Joint and the muscle power of HIP Joint were found to be important factors to predict the aerobic capacity of CP. Full article

The identification of geriatric depression and anxiety is important because such conditions are the most common comorbid mood problems that occur in older adults. The goal of this study was to build a machine learning framework that identifies geriatric mood disorders of depression and anxiety using low-cost activity trackers and minimal geriatric assessment scales. We collected activity tracking data from 352 mild cognitive impairment patients, from 60 to 90 in age, by having them wear activity trackers on their wrist for more than a month. We then extracted the features of 24-h activity rhythms and sleep patterns from the time-series activity tracking data. To increase the accuracy, we designed a novel method to incorporate additional features from questionnaire-based assessments of the geriatric depression scale and geriatric anxiety inventory into the activity tracking features. In the multi-label classification, we applied the binary relevance method to develop two single-label classifiers for depression and anxiety. The best hyper-parameters of classification algorithms for each label were selected by comparing the classification performance. We finally selected the combination of classifiers for depression and anxiety with the lowest Hamming loss as a multi-label classifier. This study successfully demonstrated the possibility of identifying geriatric depression and anxiety using low-cost activity trackers and minimal geriatric assessment scales for use in the real fields. Full article

Force variability is potentially related to altered low-frequency oscillations in motor outputs. This study examines the contributions of low-frequency oscillations in force to altered force control performances from lower to higher targeted force levels in older women. Fourteen older women executed unilateral hand-grip force control tasks at 10% and 40% of maximum voluntary contraction (MVC). Force control performances were estimated by calculating force accuracy (root-mean-square-error), force variability (standard deviation), and force regularity (approximate entropy). We additionally quantified low-frequency oscillations in force using absolute powers across four different frequency bands: (a) 0–0.5 Hz, (b) 0.5–1.0 Hz, (c) 1.0–1.5 Hz, and (d) 1.5–2.0 Hz. The findings reveal that from lower to higher targeted force level older women show greater force error, force variability, and force regularity with increased values of absolute power in force across the four frequency bands. The multiple regression models identified a significant relationship between greater force frequency power below 0.5 Hz and more impairments in force control performances. These findings suggest that force frequency oscillation below 0.5 Hz is a key predictor indicating altered stability of task performances across different targeted force levels in older women. Full article