Comparative Analysis of Thoracic Rotation Exercises: Range of Motion Improvement in Standing and Quadruped Variants.

There have been few investigations into the effectiveness of thoracic spine exercises for improving thoracic range of motion (ROM) in any plane. This study assessed the effectiveness of two thoracic spine exercises: one in the quadruped position and one in the thoracic standing position. We determined how these exercises affect thoracic spine mobility ROM over a 2-week intervention period. Thirty-nine healthy participants were enrolled and assigned to a Quadruped Thoracic Rotation group (n=17 participants: 9 females and 8 males) or Flamenco Thoracic Spine Rotation group (n=22: 14 females and 8 males). All participants were administered a KOJI AWARENESSTM screening test, and the initial thoracic spine ROM before intervention exercise was measured in a laboratory setting. Quadruped Thoracic Rotation was performed as the quadruped exercise and Flamenco Thoracic Spine Rotation as the standing exercise. The KOJI AWARENESSTM thoracic spine test and ROM were evaluated on the day after the first exercise session and again after the program. Despite their different approaches to thoracic mobility, the quadruped exercise and standing exercise achieved equivalent improvement in thoracic ROM after 2 weeks. Practitioners have a range of exercise options for enhancing thoracic mobility based on their environmental or task-specific needs.

Biomechanical characteristics of the lower extremities during running in male long-distance runners with a history of medial tibial stress syndrome: a case control study.

BACKGROUND: Medial tibial stress syndrome (MTSS) is a running-related injury of the lower extremities. After returning to competition, there are often recurring episodes of MTSS. Therefore, it is important to prevent the onset and recurrence of MTSS among long-distance runners. This case-control study aimed to compare the kinematics and kinetics of runners with and without previous MTSS during running to clarify the biomechanical characteristics of the lower extremity of runners with previous MTSS. METHODS: Thirteen male long-distance runners aged over 18 years and asymptomatic at the time of measurement were divided into an MTSS group and a non-MTSS group based on their history of MTSS as reported in a questionnaire. The kinetics and kinematics of running were analyzed when participants ran at a speed of 2.0 ± 0.2 m/s by a three-dimensional motion analysis system and two force plates. Data regarding the joint angles, moments, and powers of the ankle, knee, and hip during the stance phase while running were extracted and compared between the two groups using the Mann-Whitney U test. RESULTS: Of the 13 participants, 5 and 8 were included in the MTSS (10 legs) and non-MTSS (16 legs) groups, respectively. The ankle maximum eversion moment was significantly larger in the MTSS group than in the non-MTSS group (p = 0.04). There were no significant differences in other parameters. CONCLUSIONS: This study found that the ankle maximum eversion moment during the stance phase of running was larger in the MTSS group than in the non-MTSS group. Even after the disappearance of the symptoms of MTSS, the running biomechanics of participants with previous MTSS differed from those of participants without previous MTSS.

Kinesiophobia Is Negatively Associated With Psychological Readiness to Return to Sport in Patients Awaiting Anterior Cruciate Ligament Reconstruction.

PURPOSE: To identify the factors associated with anterior cruciate ligament return to sport after injury (ACL-RSI) scores in patients awaiting ACL reconstruction (ACLR). METHODS: This was a retrospective cross-sectional observational study conducted at a single clinical center. We recruited patients scheduled for primary ACLR, aged 16-45 years, and with modified Tegner activity scale scores ≥5 before ACL injury. The main outcome was psychological readiness to return to sport (RTS), as measured using the ACL-RSI scale. Participants' personal and injury-related information were obtained, and their psychological status (Tampa Scale for Kinesiophobia [TSK] and athletic identity measurement scale) and knee functions (effusion, range of motion, joint stability, and knee flexion angle during a single-leg squat) were examined. All variables were assessed the day before the surgery. RESULTS: A total of 105 patients (median [interquartile range]: age, 20.0 [9.0] years; body mass index, 22.8 [4.3] kg/m2; days from injury to surgery, 63.0 [65.0] days; 44% female) were enrolled. Univariate analysis indicated that only the TSK score was associated with the ACL-RSI scores (r = -0.305; P = .02). Multiple regression analysis of factors, including sex, preinjury Tegner activity scale score, and days from injury to surgery, further showed that only the TSK score was associated with the ACL-RSI scores (P = .002; 95% confidence interval -1.738 to -0.394). CONCLUSIONS: In patients awaiting ACLR, kinesiophobia was moderately negatively associated with psychological readiness to RTS, while other factors were not. LEVEL OF EVIDENCE: Level III, retrospective cross-sectional observational study.

The Tokyo 2020 Olympic and Paralympic pharmacy services during the COVID-19 pandemic.

BACKGROUND: During the Tokyo 2020 Games, pharmacists were required to provide appropriate pharmacotherapeutic care to athletes and officials at the polyclinic. Owing to the worldwide COVID-19 pandemic that was prevalent at the Games, it was imperative to strengthen infection control measures in the setting of such a major sporting event and to prevent and minimize the spread of COVID-19. OBJECTIVE: This study reports on the COVID-19 infection control measures and services provided by the pharmacy at the Tokyo 2020 Games. By evaluating pharmacy operations that took place under the COVID-19 protocol, this study provides insights for the organization of future sporting events, specifically their medical facilities. METHODS: Infection control measures in the pharmacy were implemented in accordance with the manual for dealing with COVID-19 infections. The number and content of issued and dispensed prescriptions were obtained from the electronic medical records and pharmacy department systems. These data were compared with those of the London 2012 Games, which were used as a reference for the pharmacy operations at the Tokyo 2020 Games. RESULTS: The participating pharmacists were fully trained in infection control measures. The number of prescriptions issued during the Olympics and Paralympics were 1120 and 1022, respectively. Prescriptions issued at the fever clinic accounted for 4% of the total number (77/2142). No influenza antiviral medications were prescribed, though medications to alleviate cold-like symptoms were issued. Compared to the London 2012 Games, there was a decrease (-59%) in the number of prescriptions. CONCLUSION: The positive impact of COVID-19 infection control measures was evident. The volume of prescriptions at the Tokyo 2020 Games was lower than that at the London 2012 Games. It was inferred that this was due to thorough infection control measures as well as enhanced pre-entry medical checkups before entering Japan, which reduced the incidence of diseases.

Association Between Knee Extension Strength at 3 and 6 Months After Anterior Cruciate Ligament Reconstruction.

CONTEXT: Deficits in knee extension strength after anterior cruciate ligament reconstruction have been a major problem. The inadequate recovery of the knee extension strength of surgical limb reportedly delays return to sports and increases reinjury risk. Accordingly, the early detection of knee extension strength deficits after reconstruction may help plan early interventions to manage impairment. This study aimed to clarify the association between knee extension strength at 3 and 6 months after anterior cruciate ligament reconstruction. DESIGN: Retrospective study. METHODS: Fifty patients who underwent primary anterior cruciate ligament reconstruction using hamstring grafts were included. At 3 months postoperatively, the limb symmetry index (LSI) of isokinetic knee extension strength (IKE) at 60°/s, degree of swelling, passive range of motion of knee flexion and extension, and anterior leg reach distance were measured. At 6 months postoperatively, the LSI of IKE was measured at 60°/s, which was used as the main outcome. A correlation analysis was performed with the LSI of IKE at 6 months postoperatively as the dependent variable and the LSI of IKE at 3 months postoperatively as the independent variable. Subsequently, a multiple regression analysis was performed, with LSI of IKE at 6 months postoperatively as the dependent variable; LSI of IKE at 3 months postoperatively as the independent variable; and other variables, demographic information, and surgical data as covariates. RESULTS: The correlation analysis revealed that the LSIs of IKE at 3 and 6 months postoperatively were correlated (r = .535, P < .001). In the multiple regression analysis, the LSI of IKE at 3 months postoperatively was significantly associated with that at 6 months postoperatively, even when other variables were included as covariates (R2 = .349, P = .004). CONCLUSION: Asymmetry of knee extension strength at 3 months postoperatively could be more useful than other variables related to knee strength in predicting the asymmetry of knee extension strength at 6 months postoperatively.

Imaging-detected bone stress injuries at the Tokyo 2020 summer Olympics: epidemiology, injury onset, and competition withdrawal rate.

BACKGROUND: Prevention and early detection of injuries are essential in optimising sport participation and performance. The aim of this study is to investigate the epidemiology, athlete injury history, and competition withdrawal rate of imaging-detected bone stress injuries during the Tokyo 2020 Olympic Games. METHODS: We collected and analysed imaging and clinical information in athletes with bone stress injuries diagnosed in the Olympic Village polyclinic during the Games. Two physicians independently and retrospectively reviewed all imaging examinations of bone stress injuries. RESULTS: A total of 11,315 individual athletes from 206 National Olympic Committees competed at the Games, during which 567 MRIs and 352 X-rays were performed at the Olympic Village polyclinic. Radiology examinations revealed four stress fractures and 38 stress reactions in 29 athletes (median age 24 years, range 18-35 years). Of these, 72% of athletes (n = 21) had symptoms before entering the Olympic Village. Bone stress injuries were most common in women (55%), the lower extremities (66%), and track and field athletes (45%). Six athletes (21%) did not start or did not finish their competitions. CONCLUSIONS: This study revealed 42 imaging-detected bone stress injuries in the polyclinic of the Tokyo 2020 Olympic Village. The high proportion of athletes with symptoms before entering the village and the high proportion of competition withdrawals suggests the usefulness of an early MRI examination.

Incidence and burden of injury at the Tokyo 2020 Paralympic Games held during the COVID-19 pandemic: a prospective cohort study of 66 045 athlete days.

OBJECTIVE: To describe the epidemiology of injuries at the Tokyo 2020 Paralympic Games, including injuries sustained in the new sports of badminton and taekwondo. METHODS: Injury data were obtained daily via the established web-based injury and illness surveillance system (WEB-IISS; 81 countries, 3836 athletes) and local organising committee medical facilities (81 countries, 567 athletes). Univariate unadjusted incidences (injuries per 1000 athlete days with 95% CIs), injury proportion (IP, %) and injury burden (days lost per 1000 athlete days) are reported. RESULTS: A total of 4403 athletes (1853 women, 2550 men) from 162 countries were monitored prospectively during the 3-day pre-competition and 12-day competition periods (66 045 athlete days). 386 injuries were reported in 352 athletes (IP=8.0%) with an incidence of 5.8 per 1000 athlete days (95% CI 5.3 to 6.5). Football 5-a-side (17.2), taekwondo (16.0), judo (11.6) and badminton (9.6) had the highest incidence. There was a higher incidence of injuries in the pre-competition period than in the competition period (7.5 vs 5.4; p=0.0053). Acute (sudden onset) injuries and injuries to the shoulder (0.7) and hand/fingers (0.6) were most common. Injury burden was 10.9 (8.6-13.8), with 35% of injuries resulting in time loss from training and competition. CONCLUSION: Compared with previous Paralympic Games, there was a reduction in injury incidence but higher injury burden at the Tokyo 2020 Paralympic Games. The new sports of taekwondo and badminton had a high injury incidence, with the highest injury burden in taekwondo, compared with other sports. These findings provide epidemiological data to inform injury prevention measures for high-risk sports.

Incidence and burden of illness at the Tokyo 2020 Paralympic Games held during the COVID-19 pandemic: a prospective cohort study of 66 045 athlete days.

OBJECTIVE: To describe the incidence and burden of illness at the Tokyo 2020 Paralympic Games, which was organised with strict COVID-19 countermeasures. METHODS: Daily illnesses were recorded via the web-based injury and illness surveillance system (teams with their own medical staff; n=81), and local polyclinic services (teams without their own medical staff; n=81). Illness proportion, incidence and burden were reported for all illnesses and in subgroups by sex, age, competition period, sports and physiological system. RESULTS: 4403 athletes (1853 female and 2550 male) from 162 countries were monitored for the 15-day period of the Tokyo Paralympic Games (66 045 athlete days). The overall incidence of illnesses per 1000 athlete days was 4.2 (95% CI 3.8 to 4.8; 280 illnesses). The highest incidences were in wheelchair tennis (7.1), shooting (6.1) and the new sport of badminton (5.9). A higher incidence was observed in female compared with male athletes (5.1 vs 3.6; p=0.005), as well as during the precompetition versus competition period (7.0 vs 3.5; p<0.0001). Dermatological and respiratory illnesses had the highest incidence (1.1 and 0.8, respectively). Illness burden was 4.9 days per 1000 athlete days and 23% of illnesses resulted in time loss from training/competition>1 day. CONCLUSION: The incidence of illness at the Tokyo 2020 Paralympic Games was the lowest yet to be recorded in either the summer or winter Paralympic Games. Dermatological and respiratory illnesses were the most common, with the burden of respiratory illness being the highest, largely due to time loss associated with COVID-19 cases. Infection countermeasures appeared successful in reducing respiratory and overall illness, suggesting implementation in future Paralympic Games may mitigate illness risk.

Vascular permeability of skeletal muscle microvessels in rat arterial ligation model: in vivo analysis using two-photon laser scanning microscopy.

Peripheral artery disease (PAD) in the lower limb compromises oxygen supply due to arterial occlusion. Ischemic skeletal muscle is accompanied by capillary structural deformation. Therefore, using novel microscopy techniques, we tested the hypothesis that endothelial cell swelling temporally and quantitatively corresponds to enhanced microvascular permeability. Hindlimb ischemia was created in male Wistar rat's by iliac artery ligation (AL). The tibialis anterior (TA) muscle microcirculation was imaged using intravenously infused rhodamine B isothiocyanate dextran fluorescent dye via two-photon laser scanning microscopy (TPLSM) and dye extravasation at 3 and 7 days post-AL quantified to assess microvascular permeability. The TA microvascular endothelial ultrastructure was analyzed by transmission electron microscopy (TEM). Compared with control (0.40 ± 0.15 µm3 × 106), using TPLSM, the volumetrically determined interstitial leakage of fluorescent dye measured at 3 (3.0 ± 0.40 µm3 × 106) and 7 (2.5 ± 0.8 µm3 × 106) days was increased (both P < 0.05). Capillary wall thickness was also elevated at 3 (0.21 ± 0.06 µm) and 7 (0.21 ± 0.08 µm) days versus control (0.11 ± 0.03 µm, both P < 0.05). Capillary endothelial cell swelling was temporally and quantitatively associated with elevated vascular permeability in the AL model of PAD but these changes occurred in the absence of elevations in protein levels of vascular endothelial growth factor (VEGF) its receptor (VEGFR2 which decreased by AL-7 day) or matrix metalloproteinase. The temporal coherence of endothelial cell swelling and increased vascular permeability supports a common upstream mediator. TPLSM, in combination with TEM, provides a sensitive and spatially discrete technique to assess the mechanistic bases for, and efficacy of, therapeutic countermeasures to the pernicious sequelae of compromised peripheral arterial function.

Development of a Wearable Mouth Guard Device for Monitoring Teeth Clenching during Exercise.

Teeth clenching during exercise is important for sports performance and health. Recently, several mouth guard (MG)-type wearable devices for exercise were studied because they do not disrupt the exercise. In this study, we developed a wearable MG device with force sensors on both sides of the maxillary first molars to monitor teeth clenching. The force sensor output increased linearly up to 70 N. In four simple occlusion tests, the trends exhibited by the outputs of the MG sensor were consistent with those of an electromyogram (EMG), and the MG device featured sufficient temporal resolution to measure the timing of teeth clenching. When the jaw moved, the MG sensor outputs depended on the sensor position. The MG sensor output from the teeth-grinding test agreed with the video-motion analysis results. It was comparatively difficult to use the EMG because it contained a significant noise level. Finally, the usefulness of the MG sensor was confirmed through an exercise tolerance test. This study indicated that the developed wearable MG device is useful for monitoring clenching timing and duration, and the degree of clenching during exercise, which can contribute to explaining the relationship between teeth clenching and sports performance.

Multiple and early hyperbaric oxygen treatments enhance muscle healing after muscle contusion injury: a pilot study.

BACKGROUND: The optimal timing of hyperbaric oxygen (HBO2) treatments for the best recovery following muscle injury has yet to be determined. Thus, the optimal number and timing of HBO2 treatments for maximal muscle regeneration were explored. METHODS: The HBO2 treatment protocol consisted of 2.5 ATA 100% oxygen for 120 minutes. Muscle-injured rats were randomized to one of 10 groups: single HBO2 treatment immediately after injury (HBO 1T day 0), one day (HBO 1T day 1), three days (HBO 1T day 3) and five days (HBO 1T day 5) after injury; three HBO2 treatments from immediately after injury to two days after injury (HBO 3T day 0-2), from one to three days after injury (HBO 3T day 1-3), from three to five days after injury (HBO 3T day 3-5), from five to seven days after injury (HBO 3T day 5-7); five daily HBO2 treatments (HBO 5T); and no treatment (NT). RESULTS: HBO 5T and HBO 3T day 0-2, days 1-3 and days 3-5 significantly promoted CD206-positive cell infiltration, satellite cell differentiation and muscle regeneration compared to the NT group. CONCLUSION: Five HBO2 treatments and three HBO2 treatments within three days of injury promote muscle regeneration.

The Japanese version of the anterior cruciate ligament-return to sport after injury (ACL-RSI) scale has acceptable validity and reliability.

PURPOSE: The anterior cruciate ligament-return to sports after injury (ACL-RSI) scale assesses the psychological impact of returning to sports (also referred to as psychological readiness) after ACL reconstruction. The aim of this study was to evaluate important measurement properties of the Japanese version of ACL-RSI scale. METHODS: Ninety-three participants who underwent ACL reconstruction filled out the Japanese version of ACL-RSI scale, the Tampa scale for kinesiophobia (TSK), the International Knee Documentation Committee-Subjective Knee Form (IKDC-SKF), and Knee injury and Osteoarthritis Outcome Score (KOOS). To assess test re-test reliability, 50 of the 93 participants re-answered the Japanese version of ACL-RSI scale within 10 days. Floor and ceiling effects, internal consistency, construct validity, and reliability of the Japanese version of ACL-RSI scale were analysed. RESULTS: There were no floor and ceiling effects. The Japanese version of ACL-RSI scale showed good internal consistency (Cronbach's alpha = 0.912). It was positively correlated with total points of IKDC-SKF and the Lysholm score, and with the all sub-categories of the KOOS, and it was negatively correlated with the TSK. Reliability of the Japanese version of ACL-RSI scale was satisfactory. CONCLUSION: The Japanese version of ACL-RSI scale has acceptable measurement properties. It can be a useful for evaluation of psychological readiness for return to sports in Japanese athletes who undergo primary ACL reconstruction. Information provided by the Japanese version of the ACL-RSI scale may also help to identify athletes who find return to sport a challenge, and guide conversations regarding treatment and rehabilitation plans. LEVEL OF EVIDENCE: II.

Gene targeting of the transcription factor Mohawk in rats causes heterotopic ossification of Achilles tendon via failed tenogenesis.

Cell-based or pharmacological approaches for promoting tendon repair are currently not available because the molecular mechanisms of tendon development and healing are not well understood. Although analysis of knockout mice provides many critical insights, small animals such as mice have some limitations. In particular, precise physiological examination for mechanical load and the ability to obtain a sufficient number of primary tendon cells for molecular biology studies are challenging using mice. Here, we generated Mohawk (Mkx)(-/-) rats by using CRISPR/Cas9, which showed not only systemic hypoplasia of tendons similar to Mkx(-/-) mice, but also earlier heterotopic ossification of the Achilles tendon compared with Mkx(-/-) mice. Analysis of tendon-derived cells (TDCs) revealed that Mkx deficiency accelerated chondrogenic and osteogenic differentiation, whereas Mkx overexpression suppressed chondrogenic, osteogenic, and adipogenic differentiation. Furthermore, mechanical stretch stimulation of Mkx(-/-) TDCs led to chondrogenic differentiation, whereas the same stimulation in Mkx(+/+) TDCs led to formation of tenocytes. ChIP-seq of Mkx overexpressing TDCs revealed significant peaks in tenogenic-related genes, such as collagen type (Col)1a1 and Col3a1, and chondrogenic differentiation-related genes, such as SRY-box (Sox)5, Sox6, and Sox9 Our results demonstrate that Mkx has a dual role, including accelerating tendon differentiation and preventing chondrogenic/osteogenic differentiation. This molecular network of Mkx provides a basis for tendon physiology and tissue engineering.

Comparison of three approaches for femoral tunnel during double-bundle anterior cruciate ligament reconstruction: A case controlled study.

BACKGROUND: It is still controversial whether which femoral tunnel creation technique is best during anterior cruciate ligament reconstruction (ACLR). We aimed to clarify the features of three different techniques based on the femoral tunnel position created with the same tunnel-creating concept and the measurement data. METHODS: The femoral tunnel of double-bundle (DB) ACLR was created using the behind-remnant approach in a remnant preserved manner following the policy of our institute. The trans-tibial approach (TT) was applied for all primary ACL injured cases until December 2012. The trans-portal approach (TP) was applied from January to September 2013, and the outside-in approach (OI) was indicated from October 2013 to March 2014. We compared the femoral tunnel aperture positions with the postoperative three-dimensional computed tomography (3D-CT). Additionally, the femoral tunnel length and the septum distance of each anteromedial (AM) and posterolateral (PL) tunnel were analyzed. RESULTS: The AM tunnel aperture position of TT was significantly higher and shallower than that of TP in knee flexion position. The femoral tunnel length of TP was significantly shorter than that of TT and OI. The septum between each tunnel of OI trended wider than that of TT and TP. CONCLUSIONS: The AM tunnel aperture position of TT runs the risk of a high and shallow position. TP runs the risk of insufficiently short tunnel length. It is important to apply each method flexibly to each case because no single best approach was found.

Effects of hyperbaric oxygen therapy on recovery acceleration in Japanese professional or semi-professional rugby players with grade 2 medial collateral ligament injury of the knee: A comparative non-randomized study.

INTRODUCTION: The effects of hyperbaric oxygen (HBO2) therapy on sprains, ligament injuries, and muscle strains have been reported in several animal studies. In a dog model of compartment syndrome and in a rat contused skeletal muscle injury model, the significant effects of HBO2 therapy on the reduction of edema and muscle necrosis have been reported. In basic research HBO2 therapy stimulated fibroblast activity to improve the healing process. Because of this it expected that HBO2 therapy might improve focal edema and pain in the acute phase and accelerate the healing of injured tissues in athletes with a medial collateral ligament (MCL) injury of the knee. This study aimed to examine the short-term effects of HBO2 application subjectively, and the long-term effects of HBO2 therapy in Japanese professional or semi-professional rugby players with grade 2 MCL injury of the knee. METHODS: Thirty-two professional or semi-professional rugby players with grade 2 MCL injury of the knee were investigated. First, in the HBO2 group (n=16), HBO2 therapy was performed during the acute phase. Visual analog scales (VASs) immediately before and after HBO2 therapy on the same day were compared. Next, we retrospectively evaluated the time to return to play in the HBO2 (n=16) and non-HBO2 (n=16) groups. RESULTS: VAS scores for pain while walking immediately before and after HBO2 therapy on the same day were 37.4 ± 20.1 (mean ± standard deviation) and 32.4 ± 21.8, respectively (p⟨0.001). The VAS scores for pain while jogging were 50.7 ± 25.6 and 43.9 ± 25.0, respectively (p⟨0.001). The time to return to play was 31.4 ± 12.2 days in the HBO2 group and 42.1 ± 15.8 days in the non-HBO2 group, indicating a significant difference between the groups (p⟨0.05). CONCLUSION: HBO2 therapy may reduce pain and accelerate the return to play in athletes with grade 2 MCL injury of the knee in this non-randomized study.

Direct anterior versus anterolateral approach in one-stage supine total hip arthroplasty. Focused on nerve injury: A prospective, randomized, controlled trial.

BACKGROUND: The difference in clinical results between the direct anterior approach (DAA) and the anterolateral approach (ALA) for total hip arthroplasty (THA) is still unclear. The purpose of this study was to compare clinical results, including nerve injuries, between DAA and ALA in one-stage bilateral THA in a prospective, randomized controlled trial. METHODS: Thirty patients were recruited for primary bilateral THAs from 2014 to 2016. The left and right hips of each patient were randomly assigned to DAA and the others to ALA. We prospectively compared the clinical results, incidence of lateral femoral cutaneous nerve (LFCN) injury, and tensor fascia lata (TFL) atrophy considered to be related to superior gluteal nerve injury between both approaches. RESULTS: No significant difference was found in the clinical results between both sides at postoperative 1 year. Temporary symptom of LFCN injury was observed only in DAA sides (7/30, 23.3%). The ratio of 3-month postoperative to preoperative cross-sectional area of TFL on computed tomography was significantly lower on the side subjected to DAA (DAA side, 78.8 ± 22.8%) than on the side subjected to ALA (ALA side, 90.7 ± 17.7%) (p < 0.01). In magnetic resonance imaging at postoperative 1 year, the mean grade of fatty atrophy of TFL by Goutalier classification was significantly higher in DAA sides (2.00 ± 1.6) than in ALA sides (1.1 ± 1.3) (p = 0.03). CONCLUSIONS: Excellent clinical results for both DAA and ALA were achieved. LFCN injury was found only in DAA sides. Although TFL atrophy was found in both approaches, it was found significantly more in DAA sides. Our study suggested that ALA should be used rather than DAA in terms of the risk of nerve injuries.

A case-control questionnaire survey of decompression sickness risk in Okinawa divers.

BACKGROUND: Decompression sickness (DCS) is a rare condition that is often difficult to diagnose in deep-sea divers. Because of this, prevention and early diagnosis are important. In this case-control study, we examined the risk and preventive factors associated with DCS. METHODS: Our original questionnaire survey was conducted among 269 recreational divers in Okinawa. Divers who were diagnosed with DCS by a physician (n = 94) were compared with healthy recreational divers (n = 175). The questionnaire consisted of 30 items and included a dive profile. Odds ratios and multiple logistic regression analysis were used to estimate the relative risk of DCS. RESULTS: Logistic regression analysis revealed the following risk factors for DCS: a past history of DCS, drinking alcohol the evening before diving, indicating decompression stops, cold exposure after the dive, and maximum depth. Preventive factors included hydration before the dive, deep stops, safety stops and using nitrox gas. The results were reliable according to the Hosmer-Lemeshow and omnibus tests. CONCLUSION: We identified certain risk factors, together with their relative risks, for DCS. These risk factors may facilitate prevention of DCS among Okinawa divers.

Longitudinal morphological change of acetabular subchondral bone cyst after total hip arthroplasty in developmental dysplasia of the hip.

PURPOSE: The purpose of this study is to clarify morphological changes of acetabular subchondral bone cyst after total hip arthroplasty for osteoarthritis secondary to developmental dysplasia of the hip. METHODS: Two hundred and sixty-one primary cementless total hip arthroplasties of 208 patients, 18 males, 190 females, were retrospectively reviewed. Morphological changes of subchondral bone cyst were evaluated by computed tomography (CT). The mean cross-sectional area of the cyst from CT scans at 3 months postoperatively and after 7-10 years (average 8.4 years) were compared. RESULTS: Acetabular subchondral bone cysts were found in 49.0% of all cases in preoperative CT scans. There was no cyst which was newly recognized in CT scan performed after postoperative 7-10 years. All the cross-sectional areas of the cysts evaluated in this study were reduced postoperatively. CONCLUSIONS: This study revealed that acetabular subchondral bone cysts do not increase or expand after total hip arthroplasty and indicated that the longitudinal morphological change of acetabular bone cysts in patients of developmental dysplasia of the hip do not influence long-term implant fixation in total hip arthroplasty.

Limb-dominance and gender differences in the ground reaction force during single-leg lateral jump-landings.

[Purpose] The purpose of this study was to examine limb-dominance and gender differences in the magnitude of the ground reaction force during single-leg lateral jump-landings. We hypothesized that the peak ground reaction force would be larger in the non-dominant leg compared to that in the dominant leg and would be larger in females compared to that in men. [Subjects and Methods] Fifteen females and 15 males performed jump-landings sideways from a height of 20 cm, with a lateral distance of 60 cm. Vertical and medial ground reaction forces were measured, and the elapsed time from the initial contact to the peak ground reaction force was determined. The loading rate was calculated as the peak ground reaction force divided by the elapsed time from the initial contact to the peak ground reaction force. [Results] The vertical and medial peak ground reaction forces during single-leg lateral jump-landings were larger in females compared to that in males. In addition, the medial peak ground reaction force was larger for the non-dominant leg compared to that for the dominant leg. [Conclusion] The results suggest that in rehabilitation and conditioning settings, evaluations and instructions regarding attenuation are especially important for females and the non-dominant leg.

Elimination of CT-detected gas bubbles derived from decompression illness with abdominal symptoms after a short hyperbaric oxygen treatment in a monoplace chamber: a case report.

We report the case of a 54-year-old male compressed-air worker with gas bubbles detected by computed tomography (CT). He had complained of strong abdominal pain 30 minutes after decompression after working at a pressure equivalent to 17 meters of sea water for three hours. The initial CT images revealed gas bubbles in the intrahepatic portal vein, pulmonary artery and bilateral femoral vein. After the first hyperbaric oxygen treatment (HBO2 at 2.5 atmospheres absolute/ATA for 150 minutes), no bubbles were detected on repeat CT examination. The patient still exhibited abdominal distension, mild hypesthesia and slight muscle weakness in the upper extremities. Two sessions of U.S. Navy Treatment Table 6 (TT6) were performed on Days 6 and 7 after onset. The patient recovered completely on Day 7. This report describes the important role of CT imaging in evaluating intravascular gas bubbles as well as eliminating the diagnosis of other conditions when divers or compressed-air workers experience uncommon symptoms of decompression illness. In addition, a short treatment table of HBO2 using non-TT6 HBO2 treatment may be useful to reduce gas bubbles and the severity of decompression illness in emergent cases.