Effect of CO2 and H2 gas mixture in cold water immersion on recovery after eccentric loading

Background

The findings of previous studies support the efficacy of cold water immersion (CWI) with carbon dioxide (CO2) in enhancing muscle blood flow and maintaining aerobic performance efficiency. We hypothesize that the addition of hydrogen gas (H2), known for its antioxidant properties and role in inflammation regulation, to C-CWI can enhance recovery after eccentric exercise.

Subjects

and Methods: Thirty-four healthy subjects performed a knee-extensor eccentric exercise. They were randomly allocated into four groups: control, CWI, CO2-rich CWI (C-CWI), and CO2 + H2 gas mixture CWI (CH-CWI). In the three CWI groups, all subjects were immersed in the appropriate bath at 20 °C for 20 min immediately after 60 repetitions of eccentric exercise. Before exercise and after 48 h of recovery, the subjects' maximal voluntary isometric contraction torque (MVC-ISO), maximal voluntary concentric (MVC-CON) contraction torque, countermovement jump (CMJ) height, knee flexion range of motion (ROM), muscle soreness, and muscle thickness were measured.

Results

In the CH-CWI group only, the MVC-ISO, CMJ height, and ROM did not decrease significantly post-exercise, whereas all of these decreased in the other three groups. Muscle soreness at palpation, contraction, and stretching significantly increased post-exercise in all groups. Echo intensity and tissue hardness did not increase significantly in the CH-CWI group.

Conclusions

CH-CWI stimulated recovery from impairments in MVC-ISO torque, CMJ height, knee-flexion ROM, tissue hardness, and echo intensity. These findings indicate that CH-CWI can promote recovery after eccentric exercise.

Synergistic Dominance Induced by Hip Extension Exercise Alters Biomechanics and Muscular Activity During Sprinting and Suggests a Potential Link to Hamstring Strain

ABSTRACT

Iguchi, J, Hojo, T, Fujisawa, Y, Kuzuhara, K, Yanase, K, Hirono, T, Koyama, Y, Tateuchi, H, and Ichihashi, N. Synergistic dominance induced by hip extension exercise alters biomechanics and muscular activity during sprinting and suggests a potential link to hamstring strain. J Strength Cond Res 37(9): 1770-1776, 2023-Hamstring strain is likely to occur during the late swing phase or the first half of the stance phase in sprinting. During the late swing phase, the hamstrings and gluteus maximus (Gmax) contract eccentrically to decelerate the lower limb. We hypothesized that, when the Gmax becomes dysfunctional because of delayed onset muscle soreness (DOMS), the hamstring workload is increased (i.e., there is synergetic dominance), which could lead to an increased risk of strain. A total of healthy 15 male undergraduate or graduate students (age 23.1 ± 1.28 years) were recruited to perform exercises and maximal sprints. On day 1, before subjects performing DOMS-causing exercises, and on day 3, while subjects were experiencing DOMS in the Gmax, lower-limb biomechanical and muscle activity data were recorded using a motion analysis system and electromyography (EMG), respectively. Data were analyzed and compared between day 1 and day 3. Hip flexion angle on day 3 was significantly lower than that on day 1, but the opposite was true for the knee flexion angle (P < 0.05). Vastus medialis (VM), biceps femoris (BF), and Gmax muscle activities on day 3 were significantly higher than those on day 1 (P < 0.05). Peak propulsive forces on day 3 were significantly higher than those on day 1 (P < 0.05). Kinematic changes such as decreased hip flexion angle and EMG changes such as increased BF EMG activity on day 3 to compensate for the loss of function of the Gmax may potentially increase the risk of hamstring strain.

The field study about the effects of artificial CO2-rich cool-water immersion after outdoor sports activity in a hot environment

Background/objective

In our previous laboratory experiment (room temperature of 25 °C), CO₂-rich cool-water immersion (CCWI) suppressed subjects' core body temperature even during repeated exercise. It is unclear whether the suppression of body temperature elevation would also continue after CCWI in a hot outdoor environment. Herein we investigated the thermal effects of CCWI after regular exercise training in heat on subjects' core temperature (T_core), three skin temperatures (T_skin), heart rate (HR), and the rate of perceived ice (RPI).

Methods

Thirty-six subjects (25 males, 11 females) were randomly allocated into three groups (CCWI, CWI, and control). After training at their competitive clubs, each subject was immersed up to the chest in CCWI or CWI at 20 °C for 20 min, followed by a 60-min recovery period. T_core, T_skin, HR, and RPI were measured at the initial rest, the end of immersion, and every 10 min during the recovery period.

Results

Compared to the control, the CCWI subjects' T_core was significantly lower at 50-60 min after the end of immersion (p < 0.05). T_skin at abdominal and lower-leg regions during the recovery period was maintained at significantly lower values in the CWI and CCWI groups versus control (p < 0.05). The CCWI subjects maintained lower T_skin for a longer time than the CWI subjects.

Conclusions

These findings indicate that CCWI suppresses the rise in body temperatures more than CWI, even in a hot environment, suggesting that CCWI may be a more effective countermeasure against increasing body temperature in a hot outdoor environment.

Acute changes in passive stiffness of the individual hamstring muscles induced by resistance exercise: effects of muscle length and exercise duration

PURPOSE

A previous study revealed that resistance exercise with eccentric contraction and a wide range of motion (ROM) can acutely decrease muscle stiffness of a specific muscle. To explore further approaches to decrease the stiffness, we examined the acute changes in passive stiffness of the individual hamstring muscles after eccentric-only resistance exercise with different combinations of muscle lengths and exercise durations.

METHODS

Thirteen healthy young male participants performed three sessions of eccentric-only exercises that comprised stiff-leg deadlift with different muscle lengths and exercise durations (duration per repetition × the total number of repetitions) on separate days as follows: (1) short muscle lengths with a short duration (SS); (2) long muscle lengths with a short duration (LS); and (3) long muscle lengths with a long duration (LL). Maximal joint ROM, passive torque, shear modulus of each hamstring muscle, and maximal isometric torque of knee flexion were measured before, and at 3, 30, and 60 min after each session.

RESULTS

The shear modulus of the semimembranosus was significantly lower at 3 min post-exercise (129.8 ± 22.7 kPa) than at pre-exercise (140.5 ± 19.1 kPa, p < 0.01) in LL, but not in SS or LS. No significant differences were observed in the shear moduli of the biceps femoris long head or semitendinosus between pre-exercise and 3 min post-exercise in any session.

CONCLUSION

The combination of long muscle lengths and a long duration during eccentric-only resistance exercise is important to immediately decrease the stiffness (shear modulus) of a specific muscle.

Side-To-Side Difference in Electromyographic Activity of Abdominal Muscles during Asymmetric Exercises

A side-to-side difference in the muscle size of the rectus abdominis has been suggested to increase the strain injury risk. Attenuating the difference in size of the rectus abdominis may decrease the injury risk. To explore ways to highly activate one side of the rectus abdominis, we aimed to clarify the activity levels of both sides of the muscle during asymmetric abdominal exercises. Fifteen male sprinters performed the following five asymmetric exercises for the right and left sides: (i) sit-up twist, (ii) oblique leg raise, (iii) side bridge, (iv) side bridge roll out with the elbow, and (v) side bridge roll out with the foot. Side bridge roll out with the elbow and that with the foot were performed using a wheeled platform. During the exercises, electromyographic signals were recorded bilaterally from the upper, central, and lower portions of the rectus abdominis. We calculated the root mean square of electromyograms during the concentric and eccentric phases of the exercises and normalized to that during maximal voluntary contractions. In all portions of the rectus abdominis, the root mean squares of electromyograms were significantly higher in the moving side than in the non-moving side during the concentric and eccentric phases of the side bridge, the side bridge roll out with the elbow and that with the foot (all p < 0.01), but not in sit-up twist or oblique leg raise. The root mean squares of electromyograms of all portions of the rectus abdominis in the moving side were significantly higher in the side bridge roll out with the elbow and that with the foot than in the side bridge during both phases (all p < 0.01). The results suggest that the application of the wheeled platform to side bridge is useful to highly activate one side of the rectus abdominis.

The Acute Effects of a Single Dose of Molecular Hydrogen Supplements on Responses to Ergogenic Adjustments during High-Intensity Intermittent Exercise in Humans

This research examined the effects of single-dose molecular hydrogen (H₂) supplements on acid-base status and local muscle deoxygenation during rest, high-intensity intermittent training (HIIT) performance, and recovery. Ten healthy, trained subjects in a randomized, double-blind, crossover design received H₂-rich calcium powder (HCP) (1500 mg, containing 2.544 μg of H₂) or H₂-depleted placebo (1500 mg) supplements 1 h pre-exercise. They performed six bouts of 7 s all-out pedaling (HIIT) at 7.5% of body weight separated by 40 s pedaling intervals, followed by a recovery period. Blood gases’ pH, PCO₂, and HCO₃⁻ concentrations were measured at rest. Muscle deoxygenation (deoxy[Hb + Mb]) and tissue O₂ saturation (S_tO₂) were determined via time-resolved near-infrared spectroscopy in the vastus lateralis (VL) and rectus femoris (RF) muscles from rest to recovery. At rest, the HCP group had significantly higher PCO₂ and HCO₃⁻ concentrations and a slight tendency toward acidosis. During exercise, the first HIIT bout’s peak power was significantly higher in HCP (839  ±  112 W) vs. Placebo (816  ±  108 W, p = 0.001), and HCP had a notable effect on significantly increased deoxy[Hb + Mb] concentration during HIIT exercise, despite no differences in heart rate response. The HCP group showed significantly greater O₂ extraction in VL and microvascular (Hb) volume in RF during HIIT exercise. The HIIT exercise provided significantly improved blood flow and muscle reoxygenation rates in both the RF and VL during passive recovery compared to rest in all groups. The HCP supplement might exert ergogenic effects on high-intensity exercise and prove advantageous for improving anaerobic HIIT exercise performance.

Acute changes in passive stiffness of the individual hamstring muscles induced by resistance exercise: effects of contraction mode and range of motion

PURPOSE

Recent studies raise an interesting possibility that resistance exercise also decreases passive muscle stiffness, as does stretching exercise. However, little is known about how program variables of resistance exercise acutely influence muscle stiffness. We aimed to examine the acute changes in passive stiffness of the individual hamstring muscles after resistance exercises using different combinations of contraction modes and ranges of motion (ROMs).

METHODS

Thirteen healthy young male participants performed three sessions of resistance exercises that comprised stiff-leg deadlift with different contraction modes and exercise ROMs on separate days as follows: (1) eccentric contractions with a wide exercise ROM (EW); (2) eccentric contractions with a narrow exercise ROM (EN); and (3) concentric contractions with a wide exercise ROM (CW). Maximal joint ROM, passive torque, shear modulus of the individual hamstring muscles, and maximal isometric torque of knee flexion were measured before and 3 min, 30 min, and 60 min after completing each session.

RESULTS

The shear modulus of the semimembranosus was significantly lower at 3 min post-exercise (121.8 ± 16.0 kPa) than at pre-exercise (129.0 ± 18.9 kPa, p = 0.021, r = 0.45) in EW, but not in EN or CW. There were no significant changes in the shear moduli of the biceps femoris long head or the semitendinosus at any timepoint in any exercise protocols.

CONCLUSIONS

The present results suggest that the combination of eccentric contraction and wide ROM during resistance exercise has the potential to acutely decrease passive stiffness (shear modulus) of a specific muscle.

Physical and performance characteristics related to starter status, position, and division in Japanese collegiate American-football players

BACKGROUND: Few studies have investigated the variations in body composition and performance in Japanese collegiate American-football players. OBJECTIVE: To clarify what characterizes competitors at the highest levels – in the top division or on the starting lineup – we compared players’ body compositions and performance test results. METHODS: This study included 172 players. Each player’s body composition and performance (one-repetition maximum bench press, one-repetition maximum back squat, and vertical jump height) were measured; power was estimated from vertical jump height and body weight. Players were compared according to status (starter vs. non-starter), position (skill vs. linemen), and division (1 vs. 2). Regression analysis was performed to determine characteristics for being a starter. RESULTS: Players in higher divisions and who were starters were stronger and had more power, greater body size, and better performance test results. Players in skill positions were relatively stronger than those in linemen positions. Vertical jump height was a significant predictor of being a starter in Division 1. CONCLUSION: Power and vertical jump may be a deciding factor for playing as a starter or in a higher division.

The Effects of Hydrogen Supplement on Cycling Performance During Aerobic and Anaerobic Exercise in Humans: A Pilot Study

Objectives

In this study we investigated the effects of hydrogen (H2) supplement, in the form of calcium bound H2 powder capsules, on aerobic and anaerobic cycling exercise.

Methods

Trained male subjects participated in a randomized, double-blind, crossover design trial and received H2-rich calcium powder (HCP) supplement (1500 mg/day, 2.544 μg/day of H2 gas) or H2-depleted placebo (PLA) (1500 mg/day) for 3 consecutive days.

Aerobic experiment: Eighteen subjects carried out a cycling incremental exercise starting at 20 watts (W) work rate, and increasing by 20 W/2 minutes until exhaustion. Blood gases including pH, bicarbonate ion (HCO3−), partial pressures of CO2 (PCO2), metabolic profile including lactate (Lac), and electrolytes including chloride (Cl−) were measured at rest and at 120-, 200-, and 240-W work rates.

Anaerobic experiment: Six subjects carried out a 30 second Wingate anaerobic exercise test (WAnT) bout with a resistive load of 7.5% of body mass. Lac was then measured at 1-, 3-, 5-, and 15-minutes following the WAnT exercise.

Results

Aerobic experiment: At rest, HCP had a significantly lower pH (P = 0.048), Cl− (P = 0.011), and a higher HCO3− (P = 0.041), PCO2 (P = 0.026) compared to the PLA group. During exercise, pH decrease (supplement effect: P = 0.043) and the HCO3− increase (supplement effect: P = 0.030) continued in the HCP group. Additionally, HCP did not affect peak work load and exercise duration. And no changes were noted in Lac at rest or during exercise.

Anaerobic experiment: HCP did not affect peak power output or Lac recovery following WAnT. However the average power output during exercise was significantly higher in the HCP group (P = 0.019) compared to the PLA group.

Conclusions

HCP supplementation following 3 days of intake, slightly lowered pH during aerobic exercise, and increased average power output in the anaerobic WAnT exercise compared to the PLA group. HCP supplement might have an ergogenic effect in an anaerobic exercise setting.

Funding Sources

This study was supported by The Japan Society for the Promotion of Science, and the Ministry of Education, Science, and Culture of Japan. In addition, we received a research grant from the company ENAGEGATE Inc. and they provided the HCP supplement and placebo. However, no intercession, restrictions or agreements of any kind was imposed between parties regarding research design, results or publications.

Effects of artificial CO2-rich cold-water immersion on repeated-cycling work efficiency

We investigated the acute effects of cold-water immersion (20°C) with higher CO₂ concentration (CCWI) following a high-intensity Wingate anaerobic exercise test (WAnT) on subjects' sublingual temperature (T_sub), blood lactate ([La]b), heart rate (HR), and aerobic cycling work efficiency (WE) compared to cold tap-water immersion (20°C; CWI) and passive recovery (PAS). Fifteen subjects completed three testing sessions at 1-week intervals. Each trial consisted of a first WE and WAnT, and a 20-min recovery intervention (randomized: CCWI, CWI, and PAS) before repeating a second WE and WAnT. The WE was measured by the metabolic demand during 50%V̇O₂max exercise. HR, T_sub, and [La]b were recorded throughout the testing sessions. There was a significant decline in the WE from 1st bout to 2nd bout at each recovery intervention. The WAnT was also significantly reduced at 2nd bout. Significantly reduced [La]b was achieved at CCWI compared to PAS, but not to the CWI. Likewise, the reduction in HR following immersion was the largest at CCWI compared to the other conditions. These findings indicate that CCWI is an effective intervention for maintaining repeated cycling work efficiency, which might be associated with reduced [La]b and HR.

Seasonal Changes in Anthropometric, Physiological, Nutritional, and Performance Factors in Collegiate Rowers

Iguchi J, Kuzuhara, K, Katai, K, Hojo, T, Fujisawa, Y, Kimura, M, Yanagida, Y, and Yamada, Y. Seasonal changes in anthropometric, physiological, nutritional, and performance factors in collegiate rowers. J Strength Cond Res 34(11): 3225-3231, 2020-Well-controlled seasonal distribution of training intensity seems to be an important variable for endurance athletes' success as competitors and for avoidance of overtraining. The aim of this study was to examine the interrelationships of training distribution, body composition, energy intake/expenditure, and rowing ergometer performance throughout the 2012-2013 season. In this study of 15 collegiate male rowers, most of whom started rowing during their time at the university, we divided the 2012-2013 season (total 37 weeks) into 3 phases (off-season, December to mid-March, 16 weeks; pre-season, late March-April, 5 weeks; and in-season, May-August, 16 weeks) and analyzed the transition of 2,000-m rowing ergometer time, training intensity/volume, body composition (body mass and body fat), and energy intake/expenditure in each phase. There were significant main effects of the training time by the intensities; 2,000-m rowing ergometer time; energy expenditure; and protein, fat, and carbohydrate intake across the seasons (p < 0.05). Two findings were particularly important. First, on-water high-intensity training, especially for inexperienced rowers, may contribute to improvement of 2,000-m rowing ergometer performance. Second, higher intake of carbohydrate, and to a lesser degree, protein, is necessary for optimal training adaptation (e.g., increase of muscle glycogen content), and results in better 2,000-m performance on the rowing ergometer. Also, those findings may be beneficial to the coaches who are interested in designing the well-controlled seasonal training program, which is especially intended to improve the 2,000-m rowing ergometer performance as well as avoidance of overtraining.

Application of carbon dioxide to the skin and muscle oxygenation of human lower-limb muscle sites during cold water immersion

Background

Cold therapy has the disadvantage of inducing vasoconstriction in arterial and venous capillaries. The effects of carbon dioxide (CO₂) hot water depend mainly on not only cutaneous vasodilation but also muscle vasodilation. We examined the effects of artificial CO₂ cold water immersion (CCWI) on skin oxygenation and muscle oxygenation and the immersed skin temperature.

Subjects and Methods

Fifteen healthy young males participated. CO₂-rich water containing CO₂ >1,150 ppm was prepared using a micro-bubble device. Each subject’s single leg was immersed up to the knee in the CO₂-rich water (20 °C) for 15 min, followed by a 20-min recovery period. As a control study, a leg of the subject was immersed in cold tap-water at 20 °C (CWI). The skin temperature at the lower leg under water immersion (T_sk-WI) and the subject’s thermal sensation at the immersed and non-immersed lower legs were measured throughout the experiment. We simultaneously measured the relative changes of local muscle oxygenation/deoxygenation compared to the basal values (Δoxy[Hb+Mb], Δdeoxy[Hb+Mb], and Δtotal[Hb+Mb]) at rest, which reflected the blood flow in the muscle, and we measured the tissue O₂ saturation (S_tO₂) by near-infrared spectroscopy on two regions of the tibialis anterior (TA) and gastrocnemius (GAS) muscles.

Results

Compared to the CWI results, the Δoxy[Hb+Mb] and Δtotal[Hb+Mb] in the TA muscle at CCWI were increased and continued at a steady state during the recovery period. In GAS muscle, the Δtotal[Hb+Mb] and Δdeoxy[Hb+Mb] were increased during CCWI compared to CWI. Notably, S_tO₂values in both TA and GAS muscles were significantly increased during CCWI compared to CWI. In addition, compared to the CWI, a significant decrease in T_sk at the immersed leg after the CCWI was maintained until the end of the 20-min recovery, and the significant reduction continued.

Discussion

The combination of CO₂ and cold water can induce both more increased blood inflow into muscles and volume-related (total heme concentration) changes in deoxy[Hb+Mb] during the recovery period. The T_sk-WI stayed lower with the CCWI compared to the CWI, as it is associated with vasodilation by CO₂.

Ground golf-induced changes in the blood pressure of healthy elderly people

Background

Ground golf is a popular sport among the elderly in Japan. Several types of exercise can reduce the body's mean arterial pressure (MAP), but little is known about how ground golf affects the MAP. We investigated the effects of ground golf on the MAP and the oxygen uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$\end{document}V˙O2) in a healthy elderly population.

Participants and methods

Thirteen elderly Japanese people (3 males and 10 females, mean age of 66 years) participated. All participants played 8 holes of ground golf 6 times, as game (G)1 to G6. The MAP, heart rate (HR), and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$\end{document}V˙O2 were measured at rest and every 5 min during each game.

Results

A linear trend analysis revealed that participants’ MAP values progressively decreased as each game proceeded with marginal differences (p = 0.054). There were no significant differences in HR between at rest and any of the games. The \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$\end{document}V˙O2 during the games (except for G6) were significantly higher than that at-rest (p < 0.05). The resting MAP values were negatively associated with the ground golf-induced changes in MAP (r = 0.786, p = 0.001). The participants with greater changes in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$\end{document}V˙O2 during the games showed significantly greater reductions in MAP (r = 0.276, p = 0.043).

Conclusions

Playing ground golf reduced the participants’ MAP and increased their \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$\end{document}V˙O2. Participants with higher resting MAP experienced greater reductions in MAP by playing ground golf, which suggests that ground golf can be a useful recreational sport for the elderly.

In-match physical demands on elite Japanese rugby union players using a global positioning system

Objectives

Our aim of this study was to quantify the physical demands of elite rugby union players by each position as a step towards designing position-specific training programme using a Global Positioning System/accelerometer system.

Methods

This study was performed as a retrospective observational study. Data were obtained from 45 official matches. The sample size used for the analysis was 298. The per-match total distances, accelerations and impacts were calculated and statistically compared for the forwards and backs and for individual positions.

Results

Total distances for the forwards and backs were 5731.1±507.8 and 6392.1±646.8 m, respectively. The high-velocity running distances (>18.0 km/hour) covered by the forwards and backs were 317.4±136.9 and 715.0±242.9 m, respectively. The number of accelerations (>1.5 m/s²) for the forwards and backs were 76.3±18.9 and 100.8±19.6 times, respectively, and the number of high impacts (>10 g) were 48.0±46.9 and 35.6±28.3 times for the forwards and backs, respectively. All characteristics were significantly different between the forwards and backs (p<0.05). The per-position characteristics were also calculated. Within the backs, scrum half (SH) and wingers (WTBs) covered high-velocity running significantly higher distance than fly-half (SH d=2.571, WTBs d=1.556) and centres (SH d=1.299, WTBs d=0.685) (p<0.05).

Conclusion

By clarifying the physical demands according to the positions, it will be possible to create optimised position-specific training programmes.

Evaluation of a Novel Device for Assessing Ballet Dancers' Functional Turnout

Despite various approaches to measuring ballet dancers' turnout, no standardized method for doing so has yet been estab- lished. Here a newly designed rotational goniometer (RGM) for assessing ballet dancers' functional turnout is evaluated. Twenty experienced female ballet dancers participated in the study. Measurements of the dancers' turnout were taken three times in each of the following conditions: 1. while standing on the RGM device (RGMT); 2. as if the participant was in a ballet class (CT); and 3. performing an active external rotation of the lower extremities in the supine position (AT). The angles obtained in the three trials in each condition were averaged and the results of the three conditions were compared. The mean angle of RGMT (RGMT_angle: 103.89° ± 15.2°) was significantly smaller than those of the CT (CT_angle: 128.7° ± 15.1°) and AT (AT_angle: 110.09° ± 17.6°) conditions (p < 0.05 and p < 0.01, respectively). The greatest angle (i.e., the CT_angle) is influenced by both friction and weightbearing. The AT_angle is released from weightbearing, unlike the RGMT_angle. Positive correlations were revealed between the RGMT_angle and the AT_angle (r = 0.78, p < 0.01) and between the RGMT_angle and the CT_angle (r = 0.57, p = 0.05). These findings demonstrate that the novel RGM device, characterized by elimination of friction and full weightbearing, is useful for assessing ballet dancers' functional turnout.

Abstract OT2-01-05: A randomized controlled trial comparing post-operative intensive follow-up with standard follow-up in high-risk breast cancer patients (JCOG1204: INSPIRE)

Background: The standard follow-up after surgery for breast cancer includes periodic interviews, clinical examinations, and mammography, but many institutions are conducting intensive follow-up including periodic computed tomography(CT), magnetic resonance imaging(MRI), and bone scintigraphy in the world, despite the lack of evidence to support this approach. While intensive follow-up may contribute to prolonged survival through earlier diagnosis and treatment of relapse, it has the disadvantages of high effort and costs placed on patients(pts) and healthcare workers, radiation exposure for imaging examinations, and overtreatment owing to false-positive results. Although past two randomized trials could not show significant difference in overall survival (OS), as imaging methods have remarkably improved, leading to the earlier detection of relapse, and medical therapies have remarkably improved in recent years, randomized controlled trials are needed to confirm whether intensive follow-up can really prolong survival sufficiently to offset these disadvantages in high-risk breast cancer pts.

Trial design: This study is a multi-institutional two-arm open label randomized controlled phase III trial being conducted with the participation of 42 hospitals belonging to the Breast Cancer Study Group of Japan Clinical Oncology Group. Eligible pts are randomized either to the intensive follow-up group or to the standard follow-up group; the former will undergo physical examination, bone scintigraphy, chest and abdominal CT, brain MRI/CT and frequent tumor markers, whereas the latter will undergo physical examination at the same frequency and tumor markers will be evaluated once a year. Mammography once a year is planned for both groups. This trial has been registered at the UMIN Clinical Trials Registry as UMIN000012429.

Eligibility criteria: High-risk breast cancer pts, who are expected to have recurrence rates of over 30% within 5 years after surgery. The main inclusion criteria are as follows: four or more axillary nodal metastases in the estrogen receptor (ER) positive pts without neoadjuvant chemotherapy(NC)., axillary node metastases in ER-negative pts without NC, axillary nodal metastases in ER-positive pts with NC, histologically proven residual invasive cancer in the breast or axilla in ER-negative with NC.

Specific Aims: The primary endpoint is OS, and secondary endpoints are disease-free survival, relapse-free survival, distant metastasis–free survival, OS in intrinsic subtypes, actual number of implemented examinations, compliance with pre-specified examinations, and adverse events.

Statistical methods: The primary endpoint will require a total of 538 events to be assessed in order to obtain a statistical power of 80% with a one-sided significance level of 0.05. Thus, the planned sample size to compare the two survival curves is set at 1500 pts, assuming an accrual time of 6 years and a follow-up time of 7 years according to the Schoenfeld and Richter's method.

Present accrual and target accrual: The trial was activated in November 2013. 773 pts have been enrolled by the end of June 2018.

Contact: Principal investigator Takashi Hojo MD tahojo@east.ncc.go.jp

Citation Format: Hojo T, Masuda N, Shibata T, Mizutani T, Shien T, Kinoshita T, Iwatani T, Kanbayashi C, Kitagawa D, Tsuneizumi M, Iwata H. A randomized controlled trial comparing post-operative intensive follow-up with standard follow-up in high-risk breast cancer patients (JCOG1204: INSPIRE) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-01-05.

Pudendal Nerve Electroacupuncture for Lumbar Spinal Canal Stenosis – a Case Series

Objective

To investigate the effectiveness of pudendal nerve electroacupuncture for lumbar and lower limb symptoms in patients with lumbar spinal canal stenosis for whom acupuncture of the lumbar and lower limb muscles had been ineffective.

Methods

Nine patients with lumbar spinal canal stenosis for whom conventional acupuncture at the lumbar and lower limb muscles had no effect. Pudendal nerve electroacupuncture was performed eight times (once per week). VAS scores and continuous walking distance were used to evaluate changes in symptoms.

Results

The following changes in symptoms occurred after pudendal nerve electroacupuncture: low back pain was improved from 45.3±17.4mm (mean ± SD) to 39.2±14.0mm, lower limb pain was improved from 61.1±5.6mm to 35.4±11.9mm, lower limb dysaesthesia was improved from 63.9±8.4mm to 46.9±16.2mm, and continuous walking distance was improved from 100.0±35.4m to 250.0±136.9m.

Conclusion

Pudendal nerve electroacupuncture may be an effective treatment for lumbar and lower limb symptoms due to spinal canal stenosis, and is potentially useful in patients who have not responded to conventional acupuncture.

Effects of Lumbar Acupuncture Stimulation on Blood Flow to the Sciatic Nerve Trunk - An Exploratory Study

Introduction

Acupuncture may have a role in the treatment of intermittent claudication of the cauda equina due to lumbar spinal canal stenosis. The aim of this study was to explore the possible physiological mechanisms.

Methods

In a laboratory experiment, manual acupuncture was performed at a point adjacent to the sixth lumbar vertebra of 13 animals and its effect on sciatic nerve blood flow was measured using a laser Doppler flowmetry. Simultaneously, changes in blood pressure and cardiac rate were observed. Each animal was stimulated four to eight times, making a total of 58 experiments.

Results

Acupuncture stimulation did not produce consistent changes in sciatic nerve blood flow, with increased and decreased blood flow as well as no change in blood flow observed. Among the 58 individual experiments, sciatic nerve blood flow was increased in 33, reduced in 12, and unchanged in 13. Approximately half of the stimulations showed a correlation between blood flow and blood pressure change.

Conclusion

Our results indicate that lumbar acupuncture stimulation can have an influence on sciatic nerve blood flow. The effect is dependent not only on blood pressure but also other factors, for example vasodilator and vasoconstrictor nerve activity. This mechanism may contribute to a clinical effect on intermittent claudication of the cauda equina.

Direct Current Electrical Stimulation of Acupuncture Needles for Peripheral Nerve Regeneration: An Exploratory Case Series

Objective

To examine the therapeutic effect of a novel therapeutic method based on electroacupuncture with intermittent direct current (DCEA) and associated adverse events in patients with peripheral nerve damage and a poor clinical prognosis.

Methods

In seven older patients with peripheral nerve damage (neurapraxia 2, axonotmesis 4, neuromesis 1), an acupuncture needle connected to an anode electrode was inserted proximal to the site of the injury along the route of the nerve, while the cathode electrode was inserted into the innervated muscle, and DCEA was performed (100 Hz for 20 min, weekly). Muscular paralysis was evaluated weekly with manual muscle testing, the active range of motion of joints related to the muscular paralysis and, when necessary, needle electromyography. Adverse events were also recorded during the course of the treatment.

Results

Complete functional recovery was observed in the two cases with neurapraxia and two with axonotmesis, while one axonotmesis case achieved improvement and the other showed reinnervation potential without functional recovery. No improvement was observed in the neurotmesis case. Pigmentation of the skin where the anode needle was inserted occurred in three cases. Although there was no definite causal link, one case showed excessive formation and resorption of bone in the area close to the cathode needle site.

Discussion

Accelerated nerve regeneration caused by DCEA may contribute to recovery. The skin pigmentation and callus formation suggest that the shape of the anode electrode, current intensity and other factors should be examined to establish a safer treatment method.

The Effect of Electrical Stimulation of the Pudendal Nerve on Sciatic Nerve Blood Flow in Animals

Objective

To investigate the mechanism of the clinical effect of electroacupuncture of the pudendal nerve on the lumbar and lower limb symptoms caused by lumbar spinal canal stenosis, we studied changes in sciatic nerve blood flow during electrical stimulation of the pudendal nerve in the rat.

Methods

Using rats (n=5), efferent electrical stimulation to the pudendal nerve was performed and sciatic nerve blood flow was measured with laser Doppler flowmetry. Simultaneously, changes in the blood pressure and cardiac rate were measured. Furthermore, the effect of atropine on these responses to the stimulation was also studied.

Results

Electrical stimulation of the pudendal nerve significantly increased blood flow in the sciatic nerve transiently without increasing heart rate and systemic blood pressure. The significant increase in the sciatic nerve blood flow disappeared after administration of atropine.

Conclusion

Electrical stimulation of the pudendal nerve causes a transient and significant increase in sciatic nerve blood flow. This response is eliminated or attenuated by administration of atropine, indicating that it occurs mainly via cholinergic nerves.

Effect of Electroacupuncture on the Healing Process of Tibia Fracture in a Rat Model: A Randomised Controlled Trial

Background

Electrical stimulation is used to promote bone reunion, and is most effective when applied directly to the fracture site.

Objective

To examine the effects of electroacupuncture (EA) on the healing process of tibia fracture in a rat model.

Methods

Thirty 12-week-old male Wistar rats underwent unilateral open osteotomies of the tibiae. The rats were then assigned randomly to three groups: EA group (n=10), sham group (n=10) and control group (n=10). In the EA group, a cathodal electrode was connected to an acupuncture needle percutaneously penetrated directly at the surgery site, while an acupuncture needle inserted at 15 mm proximal to the surgery site was used as an anodal electrode. EA (50 Hz, 20 μA, 20 min) was performed daily for 3 weeks. In the sham group the acupuncture needles were inserted at the same sites but no electrical stimulation was given and in the control group, no treatment was given. The response was evaluated at 1, 3, 4 and 6 weeks after surgery by radiographic, macroscopic and mechanical examinations.

Results

The EA group showed accelerated bone healing (EA group 29.92±4.55 mm2, sham group 26.46±5.21 mm2, control group 26.19±2.81 mm2, p<0.05 at 3 weeks) and accretion of the callus (radiographic evaluation: EA group 35.66±4.37 mm2, sham group 32.60±5.73 mm2, control group 29.72±6.39 mm2, p<0.05 at 6 weeks) compared with the other groups. Mechanical testing also showed an excellent result (EA group 16.54±9.92 N, sham group 7.13±3.57 N, control group 6.67±3.12 N, p<0.05) at 6 weeks in the EA group compared with the other groups. There was no difference between the sham and control groups in any evaluation.

Conclusion

The use of EA enhanced callus development and bone mineralisation during the bone healing process.

Electroacupuncture Direct to Spinal Nerves as an Alternative to Selective Spinal Nerve Block in Patients with Radicular Sciatica – a Cohort Study

We applied electroacupuncture to the spinal nerve root by inserting needles under x ray imaging in three cases with radicular sciatica, as a non-pharmacological substitute for lumbar spinal nerve block. In all three cases, symptoms were markedly reduced immediately after electroacupuncture to the spinal nerve root. The sustained effect was noticeably longer than that of spinal nerve blocks previously performed, in two out of the three cases. We suggest that descending inhibitory control, inhibitory control at the spinal level, inhibition of potential activity by hyperpolarisation of nerve endings, or changes in nerve blood flow may be involved in the mechanism of the effect of electroacupuncture to the spinal nerve root. These results suggest that electroacupuncture to the spinal nerve root may be superior to lumbar spinal nerve block when it is applied appropriately in certain cases of radicular sciatica, taking into consideration patient age, severity of symptoms and duration of the disorder.

Spinal Nerve Root Electroacupuncture for Symptomatic Treatment of Lumbar Spinal Canal Stenosis Unresponsive to Standard Acupuncture: A Prospective Case Series

Objective

To study the effectiveness of electroacupuncture of the spinal nerve root using a selective spinal nerve block technique for the treatment of lumbar and lower limb symptoms in patients with lumbar spinal canal stenosis.

Methods

Subjects were 17 patients with spinal canal stenosis who did not respond to 2 months of general conservative treatment and conventional acupuncture. Under x-ray fluoroscopy, two acupuncture needles were inserted as close as possible to the relevant nerve root, as determined by subjective symptoms and x-ray and MRI findings, and low-frequency electroacupuncture stimulation was performed (10 Hz, 10 min). Patients received 3–5 once-weekly treatments, and were evaluated immediately before and after each treatment and 3 months after completion of treatment.

Results

After the first nerve root electroacupuncture stimulation, scores for lumbar and lower limb symptoms improved significantly (low back pain, p<0.05; lower limb pain, p<0.05; lower limb dysaesthesia, p<0.01) with some improvement in continuous walking distance. Symptom scores and continuous walking distance showed further improvement before the final treatment (p<0.01), and a significant sustained improvement was observed 3 months after completion of treatment (p<0.01).

Conclusion

Lumbar and lower limb symptoms, for which conventional acupuncture and general conservative treatment had been ineffective, improved significantly during a course of electroacupuncture to the spinal nerve root, showing sustained improvement even 3 months after completion of treatment. The mechanisms of these effects may involve activation of the pain inhibition system and improvement of nerve blood flow.

Characteristics of cardiovascular responses to an orthostatic challenge in trained spinal cord-injured individuals

Background

We investigated cardiovascular responses to an orthostatic challenge in trained spinal cord-injured (SCI) individuals compared to able-bodied (AB) individuals.

Methods

A total of 23 subjects participated, divided into three groups: seven were trained as spinal cord-injured (Tr-SCI) individuals, seven were able-bodied individuals trained as runners (Tr-AB), and nine were untrained able-bodied individuals (UnTr-AB). We measured the cardiovascular autonomic responses in all three groups during each 5-min head-up tilt (HUT) of 0°, 40°, and 80°. Stroke volume (SV), heart rate (HR), and cardiac output (Qc) as cardiovascular responses were measured by impedance cardiography. Changes in deoxyhemoglobin (∆[HHb]) and total hemoglobin (∆[Hb_tot]) concentrations of the right medial gastrocnemius muscle were measured using near-infrared spectroscopy (NIRS).

Results

As the HUT increased from 0° to 80°, Tr-SCI group showed less change in SV at all HUT levels even if HR increased significantly. Mean arterial pressure (MAP) also did not significantly increase as tilting increased from 0° to 80°. Regarding peripheral vascular responses, the alterations of ∆[Hb_tot] from 0° to 80° were less in Tr-SCI group compared to AB individuals.

Conclusion

There is a specific mechanism whereby blood pressure is maintained during a HUT in Tr-SCI group with the elicitation of peripheral vasoconstriction and the atrophy of the vascular vessels in paraplegic lower limbs, which would be associated with less change in SV in response to an orthostatic challenge.

Influence of Age on Cardiorespiratory Kinetics During Sinusoidal Walking in Humans

We sought to determine the influence of age on cardiorespiratory kinetics during sinusoidal walking in two groups: 13 healthy young subjects (YG; 7 men and 6 women, age 21 ± 2 years) and 15 healthy elderly subjects (ELD; 9 men and 6 women, age 67 ± 5 years). A treadmill’s speed was sinusoidally changed between 3 and 6 km h^-1 in the YG and between 3 and 5 km h^-1 in the ELD during periods of 1, 2, 5, and 10 min, and in a stepwise manner. We compared the groups’ heart rate (HR), ventilation (V˙_E), and gas exchange (CO₂ output (V˙CO₂) and O₂ uptake (V˙O₂)) responses. We determined the phase shift (PS) and the normalized amplitude (Amp) ratio of these kinetics in relation to the sinusoidal change in walking speed in response to the magnitude from the maximum to minimum speeds as revealed by a Fourier analysis in all cardiorespiratory variables. Both the Amp ratio and PS in the V˙_E, V˙CO₂, and V˙O₂ responses were very similar between the ELD and YG, and being independent of the periods of sinusoidal oscillations. In marked contrast, the PS of the HR kinetics was significantly slowed in the ELD compared to the YG. The Amp ratio of HR was not related to the covariance variation of HR (CVHR) at standing rest in the ELD. The HR kinetics during sinusoidal walking may not be attributable to parasympathetic nerve activity into the heart in the ELD. The slope of the Amp of V˙_E related to the Amp of V˙CO₂ (V˙_E/V˙CO₂ slope) was steeper in the ELD (0.0258) compared to the YG (0.0132), suggesting that exercise hyperpnea could be greatly induced during walking in the ELD. These findings suggest that aging influences the alterations of autonomic nervous system-dependent slower HR kinetics and exercise hyperpnea during walking in the ELD.

Conscious sedation with midazolam intravenously for a patient with Parkinson's disease and unpredictable chorea-like dyskinesia

Oral surgery can be difficult in patients with chorea-like dyskinesia, which is common in those on long-term levodopa medication for Parkinson's disease, and we know of no conclusive evidence to indicate whether conscious sedation with midazolam is effective in such cases. We report a patient in whom levodopa-induced chorea-like dyskinesia disappeared when midazolam was given intravenously for conscious sedation.

Effect of electroacupuncture stimulation on long-term recovery following Achilles tendon rupture in a rat model

AIMS

In this study we examined the effect of electroacupuncture (EA) stimulation on the mechanical strength of the rat Achilles tendon after long-term recovery.

METHODS

Using 20 rats, an Achilles tendon rupture model was created in an invasive manner. The rats were assigned to one of three groups, that received EA treatment (EA group), minimal acupuncture (MA group) or remained untreated (Control group). In the EA group, EA stimulation (5 ms, 50 Hz, 20 µA, 20 min) was applied to the rupture region over a period of 90 days (five times/week). In the MA group, needles were inserted into the same positions as in the EA group but no electrical current was applied. After 90 days the tendon was measured to calculate the cross-sectional area of the rupture region. Then, the mechanical strength of the tendon was measured by tensile testing.

RESULTS

No significant differences were observed between the three groups in cross-sectional area of the injured tendon. For maximum breaking strength, the EA group showed a significantly higher threshold compared with the Control group (P<0.05) but not the MA group (P=0.24). No significant difference was seen between the MA group and the Control group (P=0.96).

CONCLUSION

Given the EA group showed a significant increase in maximum breaking strength, it is likely that EA stimulation increases the mechanical strength of a repaired tendon after long-term recovery, and EA stimulation could be useful for preventing re-rupture.

Abstract P3-13-17: A multi-center prospective study of radiofrequency ablation therapy for small breast carcinomas

Background: As the management of breast carcinoma evolves toward less invasive treatments, the next step is the possibility of removing the primary tumor without surgery. The most promising noninvasive ablation technique is radiofrequency ablation (RFA), which can effectively kill tumor cells with a low complication rate. Our preliminary studies of RFA followed by standard surgical resection have indicated that this technique is effective for surgical ablation of small (≤ 2cm) breast tumors without extensive intraductal components (EIC).

Methods: To determine if RFA is oncologically and cosmetically appropriate for the local treatment of primary breast carcinoma, this multi-center prospective study used RFA as the sole local treatment of breast tumors ≤ 1.5cm in size on ultrasound and MRI. Exclusion criteria include receiving of preoperative chemotherapy, or the presence of invasive lobular carcinoma or invasive ductal carcinoma with suspicious EIC. After confirmation that the standard baseline core biopsy for diagnosis and measurement of tumors markers (ER, PgR, HER-2/neu expression and the presence of the Ki-67 proliferative marker) have been obtained, consent will be obtained and the patient scheduled RFA. All patients received adjuvant radiation therapy. The use and choice of systemic therapy will be based on the information from the baseline core biopsy. The first primary endpoints of this study is successful tumor ablation, as evidenced by negative findings on vacuum-assisted or core biopsies and imaging studies after RFA. The second primary endpoints is the incidence of procedure related adverse events. Forty patients with small tumors that are clearly identifiable and measurable by ultrasound and MRI were enrolled. The response to ablation was evaluated with both vacuum-assisted or core biopsies and imaging studies every 3 months during the first year. The long-term outcomes were assessed using quality of life measurement scales and imaging studies every 6 months thereafter through year 5.

Results: Of the 58 patients who participated in this study, 55 completed the protocol. In 48 of the 55 (87%) treated patients, successful tumor ablation, as determined by negative findings on vacuum-assisted or core biopsies and imaging studies, was confirmed. The remaining 7 patients with biopsies positive for residual tumor underwent surgical resection. There were no local or distant recurrences in treated 55 patients with a median follow up of 47 (range 36-73) months.

Conclusions: RFA can be safely used alone in patients with small breast tumors, provided that local tumor control must be regularly assessed by image-guided vacuum-assisted or core biopsies after ablation. RFA has several potential advantages over lumpectomy for the treatment of early stage breast cancer.

Citation Format: Kinoshita T, Ohtani S, Doihara H, Yamamoto N, Takahashi M, Fujisawa T, Aogi K, Hojo T, Asaga S, Yoshida M, Tsuda H. A multi-center prospective study of radiofrequency ablation therapy for small breast carcinomas [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-13-17.

Prevalence of posterior elbow problems in Japanese high school baseball players

BACKGROUND

Various posterior elbow problems cause posterior elbow pain among baseball players. We aimed to determine the prevalence and diagnoses associated with posterior elbow problems and post-treatment recovery time for returning to sports in Japanese high school baseball players when treated in the off-season.

METHODS

A total of 576 Japanese high school baseball players who participated in baseball skill training camp during the off-season were enrolled in the study. The elbow of each player's throwing arm was assessed by use of a questionnaire and physical examination. Players with abnormal results were advised to visit the hospital. Players who visited the hospital were initially treated conservatively and underwent surgery if necessary. Retrospectively, players with positive physical examination results associated with posterior elbow pain, defined as olecranon tenderness and/or a positive elbow extension impingement test, were selected. Information about their position, elbow pain, physical examination results, diagnosis, treatment, and recovery time before returning to playing sports was assessed.

RESULTS

Olecranon tenderness and/or positive elbow extension impingement test results were found in 76 players (13.2%). Of these, 33 agreed to visit the hospital for further diagnostic imaging and 25 players (75.8%) were diagnosed with posteromedial elbow impingement. By the next spring, 87.9% of players returned to sport, and 100% of players returned to sport before the next summer. The average recovery period was 77 ± 47 days.

CONCLUSION

Physical examinations related to posterior elbow injuries were positive in 13.2% of high school baseball players. The most common diagnosis for posterior elbow pain was posteromedial elbow impingement. All players returned to competitive sports activity levels within 77 ± 47 days.

Effects of electrical stimulation therapy on the blood flow in chronic critical limb ischemia patients following regenerative therapy

OBJECTIVES

We investigated the effects of electrical stimulation therapy on cutaneous and muscle blood flow in critical limb ischemia patients following regenerative therapy.

METHODS

Three groups were studied: 10 healthy young subjects, 10 elderly subjects, and 7 critical limb ischemia patients after regenerative therapy. After 5 min rest, electrical stimulation was applied at 5 Hz on the tibialis anterior muscle for 10 min. We estimated the relative changes in oxyhemoglobin and total hemoglobin compared to the basal values at rest (Δ[HbO2], Δ[Hbtot]), which reflected the blood flow in the skin and muscle layer, and we simultaneously measured the tissue O2 saturation (StO2) throughout the electrical stimulation and recovery phase by near-infrared spectroscopy.

RESULTS

The Δ[HbO2] and Δ[Hbtot] values of the muscle layer in critical limb ischemia patients increased gradually and remained significantly higher at the 5-min and 10-min recovery periods after the electrical stimulation without reducing the StO2, but there is no significant change in the other two groups. Skin blood flow was not influenced by electrical stimulation in three groups.

CONCLUSION

This improvement of the peripheral circulation by electrical stimulation would be beneficial as the adjunctive therapy after regenerative cell therapy.

Acupuncture for the treatment of trigger finger in adults: a prospective case series

OBJECTIVE

To determine the effect of acupuncture performed at the synovial and ligamentous tendon sheath (A1 pulley site) on pain during snapping and the severity of the snapping phenomenon in patients with trigger finger.

METHODS

In this observational study, changes in the patients' condition were compared before and after acupuncture treatment. Acupuncture was performed on 19 fingers of 15 patients. Acupuncture needles were inserted into the radial and ulnar sides of the flexor tendon at the A1 pulley of the affected finger. Treatment was performed daily up to a maximum of five times. Before and after each treatment, pain during snapping and the severity of snapping were evaluated using a visual analogue scale (VAS).

RESULTS

VAS scores for pain and snapping severity were significantly improved immediately after the first treatment (p<0.001). Pain during snapping, assessed before each treatment, improved over time, reaching statistical significance from the second treatment onwards (p<0.001); similarly, a significant improvement in the severity of snapping was observed, also from the second treatment (p<0.001). Patients with clinically significant improvements (≥50%) in pain and snapping severity had a significantly shorter duration of the disorder than those with <50% improvement (p<0.05).

CONCLUSIONS

Acupuncture at the impaired A1 pulley site may be an effective treatment for trigger finger. We postulate that acupuncture may reduce inflammation/swelling of the synovial membrane of the tendon sheath, which predominates when the disorder is of short duration. Further research is required to confirm the efficacy/effectiveness of acupuncture for trigger finger and its mechanisms of action.

Endurance training facilitates myoglobin desaturation during muscle contraction in rat skeletal muscle

At onset of muscle contraction, myoglobin (Mb) immediately releases its bound O₂ to the mitochondria. Accordingly, intracellular O₂ tension (P_mbO₂) markedly declines in order to increase muscle O₂ uptake (mO₂). However, whether the change in P_mbO₂ during muscle contraction modulates mO₂ and whether the O₂ release rate from Mb increases in endurance-trained muscles remain unclear. The purpose of this study was, therefore, to determine the effect of endurance training on O₂ saturation of Mb (S_mbO₂) and P_mbO₂ kinetics during muscle contraction. Male Wistar rats were subjected to a 4-week swimming training (Tr group; 6 days per week, 30 min × 4 sets per day) with a weight load of 2% body mass. After the training period, deoxygenated Mb kinetics during muscle contraction were measured using near-infrared spectroscopy under hemoglobin-free medium perfusion. In the Tr group, the mO₂peak significantly increased by 32%. Although the P_mbO₂ during muscle contraction did not affect the increased mO₂ in endurance-trained muscle, the O₂ release rate from Mb increased because of the increased Mb concentration and faster decremental rate in S_mbO₂ at the maximal twitch tension. These results suggest that the Mb dynamics during muscle contraction are contributing factors to faster O₂ kinetics in endurance-trained muscle.

Upgrading of anaerobic digestion of waste activated sludge by a hyper-thermophilic–mesophilic temperature-phased process with a recycle system

A hyper-thermophilic–mesophilic temperature-phased anaerobic digestion with a recycle system effectively upgraded the mesophilic digestion of waste activated sludge.

Prevalence and Clinical Characteristics of Osteochondritis Dissecans of the Humeral Capitellum Among Adolescent Baseball Players

BACKGROUND

The prevalence and clinical characteristics of osteochondritis dissecans (OCD) of the humeral capitellum among adolescent baseball players are unknown.

PURPOSE

To determine the OCD prevalence in adolescent competitive baseball players and to investigate the clinical characteristics of these patients.

STUDY DESIGN

Cross-sectional and case-control study; Level of evidence, 3.

METHODS

A total of 2433 baseball players (mean age, 14.5 ± 1.5 years) belonging to junior high school and high school baseball clubs were enrolled. Players completed a questionnaire, and the elbow of each player's throwing arm was assessed by ultrasonography. Participants with abnormal results on ultrasonography were further examined through radiographic study. The OCD lesions were classified into stages based on radiographic results, and demographic data were compared between players with and without OCD lesions.

RESULTS

Osteochondritis dissecans of the humeral capitellum was found in 82 (3.4%) elbows by ultrasonography. Players with an OCD lesion began playing baseball at an earlier age (P = .016), had a longer duration of competitive play (P = .0013), and had experienced more present (P = .0025) and past (P < .0001) elbow pain compared with players without a lesion. There were no differences between the 2 groups in the position played (P = .26). Sixty-eight patients underwent further radiographic examination for OCD (radiography, computed tomography, magnetic resonance imaging). Of these players, 10 (14.7%) were classified as having stage I OCD (radiolucent stage); 26 (38.2%), stage II (fragmentation stage); 9 (13.2%), stage III (loose body stage); 9 (13.2%), stage IV (residual stage); and 14 (23.5%), stage V (postoperative stage).

CONCLUSION

The prevalence of OCD of the humeral capitellum, including latent cases, was 3.4% among adolescent baseball players. Players with OCD lesions began playing baseball at earlier ages, had played for longer periods, and had experienced more elbow pain. The player's current baseball position may not be related to the existence of OCD lesions in adolescents.

Injuries in a Japanese Division I collegiate american football team: a 3-season prospective study

CONTEXT

Previous research on American football injuries in Japan has focused on incidence proportion in terms of the number of injuries divided by the number of players. This is the first study to examine injury rates over several seasons.

OBJECTIVE

To conduct a prospective study of injuries in a Japanese Division I collegiate American football team over the 2007 through 2009 seasons.

DESIGN

Cohort study.

SETTING

Collegiate football team at Doshisha University, Kyoto, Japan.

PATIENTS OR OTHER PARTICIPANTS

All 289 athletes who played on the collegiate Division I football team during the 2007 through 2009 seasons.

MAIN OUTCOME MEASURE(S)

A certified athletic trainer kept a daily record of all practice and game injuries. Injury rates were calculated according to season, injury type, body part, severity, and mechanism. Injuries were also analyzed according to position of player, school year, and playing experience.

RESULTS

The game injury rate (GIR; 32.7 injuries/1000 athlete-exposures) was higher than the practice injury rate (PIR; 10.9 injuries/1000 athlete-exposures) over the 3 seasons (P < .05). The PIR was higher among Japanese players than the comparable United States collegiate football injury rates (5.8-7.0 injuries/1000 athlete-exposures). Ankle and foot injuries occurred more frequently during games, whereas thigh and gluteal injuries occurred more frequently during practices.

CONCLUSIONS

Our data show differences between games and practices in terms of injury rates, body parts injured, and positions of players injured. The high PIR in Japan may be due to the increased contact during practices and length of practices compared with the United States. Further research involving multiple teams is recommended to validate the trends noted in this study. The expanded data set could assist in the development of safety regulations and preventive interventions for Japanese football.

The Effect of Electroacupuncture on Osteotomy Gap Healing in a Rat Fibula Model

Objective

To examine the effect of electroacupuncture (EA) on osteotomy gap healing in a rat fibula model.

Methods

A total of 40 12-week-old male Wistar rats underwent unilateral open osteotomy of the fibula to create a 2 mm gap. The rats were randomly assigned to an EA group (n=20) and a control group (n=20). In the EA group, a cathodal electrode was connected to an acupuncture needle percutaneously at the surgery site, while another acupuncture needle inserted 15 mm proximal to the surgery site was used as an anodal electrode. EA was performed 5 days a week for 6 weeks. The control group received no treatment. Some rats were killed at 3 days and 1 week after surgery and the cut end of the distal part of the fibula was surgically removed and histologically assessed. Haematoxylin and eosin (H&E) staining was used to measure total cell count and immunohistochemical staining to assess the increase in the bone morphogenetic protein 2 (BMP-2)-positive cells. The healing process was also assessed weekly after surgery via x-ray examinations.

Results

At each time point, total cell count showed a marked increase in the EA group (p<0.05), while BMP-2 expression showed a tendency to increase in the EA group. Radiological examination showed a marked reduction in the distance between the cut ends of the fibula in the EA group.

Conclusions

There was a marked increase in cell count and expression of growth factor in the EA group. These results indicate direct current EA could be useful for promoting bone healing.

Abstract P3-02-06: Survival impact of early detection of recurrence after surgery in early breast cancer patients

Background and Object: Annual mammography and physical examination as the follow-up tests after surgery were recommended to early breast cancer patients based on the two randomized clinical trials (GIVIO and Rosselli Del Turco) which were reported in 1990s. Whereas, radiological imaging and blood test (serum tumor marker) for early detection of recurrence are not recommended due to the lack of evidence from clinical trial. However, the imaging techniques (helical CT, bone scan, PET/CT. MRI et al) to detect minute lesions and therapeutic options for metastatic breast cancer have been remarkably advanced since then. In fact, routine radiological examinations after surgery were performed in several Japanese hospitals for aiming early detection of recurrence as the clinical practice.

We here evaluate the possible benefit of early detection of recurrence by radiological and laboratory examinations during post-operative follow-up period.

Methods: Clinical information of breast cancer patients who were diagnosed as recurrence after surgery during 2005–2006 was collected from 30 hospitals in Japan. Clinical and pathological characteristics such as molecular subtype of breast cancer, survival time from initial therapy or 1st recurrence, detection methods and symptomatic information when they diagnosed as metastasis were analyzed retrospectively.

Results: As the routine examination of post-operative follow-up, serum tumor maker, chest x-ray/CT, abdominal US/CT and bone scan were done in 95%, 57%, 38%, 24% of 30 hospitals, respectively. Of the 698 patients individually evaluated in this analysis, 248 had loco-regional recurrences and 450 had distant metastases. The first distant metastatic site were 35% in bone, 30% in lung, 17% in liver and 11% in lymph node, respectively. All individual patients are divided into symptomatic (45.7%) or asymptomatic groups (54.3%) at the detection of metastases. Asymptomatic metastases were detected by serum tumor marker (26%), bone scan (18%), chest x-ray (17%), chest CT (17%), abdominal US (11%) and abdominal CT (5%), respectively. The median disease-free interval (DFI) was 3.0 years in both groups, but the median survival time after the diagnosis of recurrence to death were 3.7 years in asymptomatic patients and 3.0 years in symptomatic patients, respectively. In addition, asymptomatic group had significantly superior overall survival (from primary surgery to death) than symptomatic group with oligo-metastases such as limited organ disease (P &lt; 0.001).

Conclusions: Our data may support the hypothesis that early detection of breast cancer recurrences has beneficial impact on survival. Randomized clinical trial would be warranted to prove this hypothesis, and we are currently planning this.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-02-06.