Quantifying the effects of ice hockey upper body pads on mobility and comfort.

Ice hockey is a high-intensity sport in which pads such as shoulder and elbow pads (S/EPs) are necessary to help players avoid injury. However, they can also affect mobility and comfort, thereby affecting players' on-ice performance. We aimed to quantify the effects of S/EPs on mobility and comfort by comparing the range of motion (ROM) of nine elite college-level ice hockey players performing static (nine single-DOF upper-body movements) and dynamic (wrist and slap shots) tasks under six pad conditions (no S/EPs and five types of S/EPs). We also analyzed the relationship between ROM and subjective comfort to provide an objective comfort evaluation of hockey pads. Five types of S/EPs restrict ROM at different levels, imposing additional mobility restrictions. We found significant differences among the five types and a high correlation between comfort and ROM. We conducted a comprehensive evaluation of the impact of ice hockey pads on mobility and comfort.

A new kinematic dataset of lower limbs action for balance testing.

Balance is a common performance but nevertheless an essential part of performance analysis investigations in ski. Many skier pay attention to the training of balance ability in training. Inertial Measurement Unit, as a kind of Multiplex-type human motion capture system, is widely used because of its humanized human-computer interaction design, low energy consumption and more freedom provided by the environment. The purpose of this research is to use sensor to establish a kinematics dataset of balance test tasks extracted from skis to help quantify skier' balance ability. Perception Neuron Studio motion capture device is used in present. The dataset contains a total of 20 participants' data (half male) of the motion and sensor data, which is collected at a 100 Hz sampling frequency. To our knowledge, this dataset is the only one that uses a BOSU ball in the balance test. We hope that this dataset will contribute to multiple fields of cross-technology integration in physical training and functional testing, including big-data analysis, sports equipment design and sports biomechanical analysis.

Development and Evaluation of a Full-Waveform Resistance Training Monitoring System Based on a Linear Position Transducer.

Recent advances in training monitoring are centered on the statistical indicators of the concentric phase of the movement. However, those studies lack consideration of the integrity of the movement. Moreover, training performance evaluation needs valid data on the movement. Thus, this study presents a full-waveform resistance training monitoring system (FRTMS) as a whole-movement-process monitoring solution to acquire and analyze the full-waveform data of resistance training. The FRTMS includes a portable data acquisition device and a data processing and visualization software platform. The data acquisition device monitors the barbell's movement data. The software platform guides users through the acquisition of training parameters and provides feedback on the training result variables. To validate the FRTMS, we compared the simultaneous measurements of 30-90% 1RM of Smith squat lifts performed by 21 subjects with the FRTMS to similar measurements obtained with a previously validated three-dimensional motion capture system. Results showed that the FRTMS produced practically identical velocity outcomes, with a high Pearson's correlation coefficient, intraclass correlation coefficient, and coefficient of multiple correlations and a low root mean square error. We also studied the applications of the FRTMS in practical training by comparing the training results of a six-week experimental intervention with velocity-based training (VBT) and percentage-based training (PBT). The current findings suggest that the proposed monitoring system can provide reliable data for refining future training monitoring and analysis.

A Comprehensive Analysis of the Validity and Reliability of the Perception Neuron Studio for Upper-Body Motion Capture.

The Perception Neuron Studio (PNS) is a cost-effective and widely used inertial motion capture system. However, a comprehensive analysis of its upper-body motion capture accuracy is still lacking, before it is being applied to biomechanical research. Therefore, this study first evaluated the validity and reliability of this system in upper-body capturing and then quantified the system's accuracy for different task complexities and movement speeds. Seven participants performed simple (eight single-DOF upper-body movements) and complex tasks (lifting a 2.5 kg box over the shoulder) at fast and slow speeds with the PNS and OptiTrack (gold-standard optical system) collecting kinematics data simultaneously. Statistical metrics such as CMC, RMSE, Pearson's r, R2, and Bland-Altman analysis were utilized to assess the similarity between the two systems. Test-retest reliability included intra- and intersession relations, which were assessed by the intraclass correlation coefficient (ICC) as well as CMC. All upper-body kinematics were highly consistent between the two systems, with CMC values 0.73-0.99, RMSE 1.9-12.5°, Pearson's r 0.84-0.99, R2 0.75-0.99, and Bland-Altman analysis demonstrating a bias of 0.2-27.8° as well as all the points within 95% limits of agreement (LOA). The relative reliability of intra- and intersessions was good to excellent (i.e., ICC and CMC were 0.77-0.99 and 0.75-0.98, respectively). The paired t-test revealed that faster speeds resulted in greater bias, while more complex tasks led to lower consistencies. Our results showed that the PNS could provide accurate enough upper-body kinematics for further biomechanical performance analysis.

A Quantitative Assessment Grading Study of Balance Performance Based on Lower Limb Dataset.

Balance ability is one of the important factors in measuring human physical fitness and a common index for evaluating sports performance. Its quality directly affects the coordination ability of human movements and plays an important role in human productive activities. In the field of sports, balance ability is an important indicator of athletes' selection and training. How to objectively analyze balance performance becomes a problem for every non-professional sports enthusiast. Therefore, in this paper, we used a dataset of lower limb collected by inertial sensors to extract the feature parameters, then designed a RUS Boost classifier for unbalanced data whose basic classifier was SVM model to predict three classifications of balance degree, and, finally, evaluated the performance of the new classifier by comparing it with two basic classifiers (KNN, SVM). The result showed that the new classifier could be used to evaluate the balanced ability of lower limb, and performed higher than basic ones (RUS Boost: 72%; KNN: 60%; SVM: 44%). The results meant the established classification model could be used for and quantitative assessment of balance ability in initial screening and targeted training.

Effects of EVA glove on hand dexterity at low temperature and low pressure.

Hand dexterity is an important index to assess whether extravehicular activity (EVA) gloves are appropriately designed. Pressurized gloves and low temperature environments can both cause a decrease in hand dexterity. However, due to the difficulty in performing tests under extreme conditions, there has been no report on dexterity tests with gloves under pressure and low temperature. To fill this gap, we performed a dexterity test of EVA gloves with twelve male volunteers involved under the extreme conditions, which were created in the low-pressure simulation cabin with vaporized liquid nitrogen used to cool it down. A total of nine conditions were designed. Purdue pegboard test and nut fastening test were improved before being applied in a hand dexterity test. Completion times for both tests, finger temperatures and cold feeling of the hand were recorded and analyzed. Results showed that the completion times for both tests increased either as the temperature decreased or as the pressure increased. Furthermore, a combined effect of low temperature and pressure was observed. The study provides evidence in support of astronaut training and optimization of EVA glove productivity.

Thermal protection study of bladder compensatory suit using a heat transfer model.

BACKGROUND: The bladder compensatory suit (BCS) is important individual protective equipment for pilots' activities in a high-flying environment. The layout and thermal diffusion ability of the bladder directly affects the thermal comfort of pilots in flight. OBJECTIVE: (1) Established and verified a human-compensatory suit-environment heat transfer model; (2) Used the model to study the human thermal variation of each segment in hot conditions and clothing. METHODS: To verify the two-dimensional heat transfer model, simulated data of body temperature were compared with experimental results under the same conditions (AT: 40/45°C, ordinary clothing). The model could be used to calculate the temperature variation of each body segment in three environments temperature (28°C, 35°C and 40°C) and three types of clothing (naked, ordinary clothing, BCS). RESULTS: The results showed that: (1) the bladder significantly affected sweating speed and skin temperature, as well as core temperature; (2) the skin temperature of the area covered by the bladder was difficult to reduce by the thermal regulation system. It was because sweat secretion was inhibited, thus, to limit evaporation. CONCLUSIONS: The model could be used as a reference for the thermal protection design of bladder compensatory suit. SUMMARY: The bladder compensatory suit (BCS) is important individual protective equipment for pilots activities in a high-flying environment, and its layout directly affects the thermal comfort. Based on a two-dimensional thermal regulation system model, a body-clothing-environment heat transfer model was established. The model was used to calculate the temperature and sweat variation of each body segment in different environments and clothing.

Spontaneous internal hemorrhage of a giant hepatic hemangioma: A case report.

RATIONALE: Hepatic hemangioma, a benign liver tumor, can rarely spontaneously rupture and hemorrhage, which is then associated with significant mortality. The diagnosis of internal hemorrhage is challenging and the management is disputed. PATIENT CONCERNS: We describe the case of a 52-year-old female patient with chief complaints of fever and anemia, with no history of recent trauma. DIAGNOSES: Ultrasound suggested the possibility of a liver abscess and computed tomography (CT) examination revealed a giant space occupying lesion (SOL) (approximately 16 cm) in the right hepatic lobe, indicating a hepatic tumor or abscess. The patient did not respond to antibiotics and blood transfusion. Liver needle biopsy revealed blood clots suggestive of intratumoral hemorrhage, possibly of a hepatic hemangioma. INTERVENTIONS: Interventional radiologic approach revealed active bleeding at the phrenic artery that supplied the liver SOL. Thus, embolization was performed and re-angiography showed no active bleeding from the embolized vessel. The patient became afebrile, but fever recurred the next day. Hence, an exploratory open right hemihepatectomy was undertaken and the intraoperative frozen biopsy confirmed hepatic hemangioma with internal hemorrhage, but malignancy could not be excluded for some focal tissues. Postoperative pathology report confirmed the diagnosis of hepatic hemangioma with internal hemorrhage and excluded malignancy. OUTCOMES: The fever subsided and the patient was discharged in good health. A follow-up CT performed three months, postoperatively, indicated compensatory growth of the left hepatic lobe. LESSONS: This case demonstrates that the diagnosis of hepatic hemangioma with internal hemorrhage can be confirmed by needle biopsy and surgical resection is the optimal treatment for such a lesion.

Effects of EVA gloves on grip strength and fatigue under low temperature and low pressure.

OBJECTIVE: To study the effects of wearing extravehicular activity (EVA) gloves on grip strength and fatigue in low temperature, low pressure and mixing of two factors (low temperature and low pressure). METHODS: The maximum grip strength and fatigue tests were performed with 10 healthy male subjects wearing gloves in a variety of simulated environments. The data was analysed using the normalization method. RESULTS: The results showed that wearing gloves significantly affected the maximum grip strength and fatigue. Pressure (29.6, 39.2 kPa) had more influence on the maximum grip compared with control group while low temperatures (-50, -90, -110 °C) had no influence on grip but affected fatigue dramatically. The results also showed that the maximum grip strength and fatigue were influenced significantly in a compound environment. CONCLUSIONS: Space environment remarkably reduced strength and endurance of the astronauts. However, the effects brought by the compound environment cannot be understood as the superimposition of low temperature and pressure effects.

Simulating extreme environments: Ergonomic evaluation of Chinese pilot performance and heat stress tolerance.

BACKGROUND: High-temperatures in the cockpit environment can adversely influence pilot behavior and performance. OBJECTIVE: To investigate the impact of high thermal environments on Chinese pilot performance in a simulated cockpit environment. METHODS: Ten subjects volunteered to participate in the tests under 40°C and 45°C high-temperature simulations in an environmentally controlled chamber. Measures such as grip strength, perception, dexterity, somatic sense reaction, and analytical reasoning were taken. The results were compared to the Combined Index of Heat Stress (CIHS). RESULTS: CIHS exceeded the heat stress safety limit after 45 min under 40°C, grip strength decreased by 12% and somatic perception became 2.89 times larger than the initial value. In the case of 45°C, CIHS exceeded the safety limit after only 20 min, while the grip strength decreased just by 3.2% and somatic perception increased to 4.36 times larger than the initial value. Reaction and finger dexterity were not statistically different from baseline measurements, but the error rate of analytical reasoning test rose remarkably. CONCLUSION: Somatic perception was the most sensitive index to high-temperature, followed by grip strength. Results of this paper may help to improve environmental control design of new fighter cockpit and for pilot physiology and cockpit environment ergonomics research for Chinese pilots.

Laparoscopic radiofrequency ablation for traumatic splenic rupture.

BACKGROUND: Laparotomy was formerly the routine approach for treating traumatic splenic rupture. Traumatic splenic rupture has traditionally been treated with open splenectomy. The advent of laparoscopy and radiofrequency ablation (RFA) has ushered in new approaches to this surgical problem. The purpose of this study was to evaluate the use of laparoscopic RFA to treat traumatic splenic rupture. METHODS: Four patients with traumatic splenic ruptures underwent laparoscopic RFA-assisted spleen-preserving surgery between September 2011 and April 2012. RFA electrodes were used for traumatic rupture repair or partial splenectomies using classic laparoscopic procedures. Safety and efficacy parameters were documented, including surgery time, intraoperative blood loss, postoperative drainage quantities, and recovery conditions. RESULTS: Three patients received laparoscopic splenic rupture repair and one patient received a partial splenectomy. Three surgeries were successful, based on 1-mo follow-up with computerized tomography and ultrasound examinations that indicated the restoration of satisfactory splenic blood supply. The fourth patient received a laparotomy for a total splenectomy because of massive postoperative bleeding 24 h after surgery. CONCLUSIONS: Laparoscopic RFA-assisted spleen-preserving surgery is another modality that may be considered in the management of splenic trauma. This small sample size and limited clinical experience does not justify its use on a routine basis and requires additional clinical research to fully evaluate its efficacy in certain critical traumatic scenarios compared with traditional open splenectomy.

[Evaluation of operation ergonomics at high-temperature in the cockpit].

10 male subjects participated in the environmental simulation study to evaluate the operation ergonomics at high-temperature in the cockpit. Grip strength, perception, dexterity, reaction and intelligence were measured respectively during the tests at 40 degrees C and 45 degrees C, simulating the high-temperatures in a simulation cockpit chamber. Then the data obtained were compared to the combined index of heat stress (CIHS). The average values of each item of the subjects' performance at the two different temperatures are compared. The results indicated that CIHS exceeded the heat stress safety line after 45 min at 40 degrees C, grip strength decreased by 12%, and perception increased by 2.89 times. In contrast, at 45 degrees C, CIHS exceeded the safety line after 20 min, grip strength decreased by 3.2%, and perception increased by 4.36 times. However, Finger dexterity was less affected. Reaction ability was first accelerated, and then slowed down. The error rate in the intelligence test increased to a greater extent. At the high temperatures, the minimum perception was the most affected, followed by grip strength, reaction and finger dexterity were less affected, while the intelligence did not decline, but rise.