Ultrasonographic diagnosis of medial meniscus posterior root tear in early knee osteoarthritis: a comparative study.

INTRODUCTION: This study aimed to detect medial meniscal posterior root tear (MMPRT) diagnostic methods with high sensitivity and specificity using dynamic ultrasonographic evaluation in patients with early knee osteoarthritis (OA) and demonstrate the usefulness of dynamic ultrasonographic medial meniscal extrusion (MME) evaluation in MMPRT diagnosis using a cutoff value. MATERIALS AND METHODS: Between 2018 and 2020, a total of 120 patients were diagnosed with early knee OA using clinical and radiographic findings. Dynamic ultrasonographic evaluations and magnetic resonance imaging were performed in all patients, and 47 patients who had and 73 patients who did not have MMPRT were classified into the MMPRT and non-MMPRT groups, respectively. Age, sex, femorotibial angle, MME of knee extension and flexion, and MME at weight-bearing were compared between the two groups. Additionally, the sensitivity and specificity of significant ultrasonographic findings were calculated using a receiver operating characteristic (ROC) curve. RESULTS: The MMEs under knee extension-flexion and weight-loading in the MMPRT group were significantly larger than those in the non-MMPRT group. ROC curve analysis for each ultrasonographic evaluation condition to diagnose MMPRT indicated that the sensitivity was 72-88% and the specificity was 66-85% when the cutoff values of MME under knee flexion at 0°, 90°, and weight-loading were set at 2.55 mm, 2.00 mm, and 3.55 mm, respectively. The highest sensitivity (88%) and specificity (85%) were exhibited upon > 2 mm MME at a knee flexion of 90° and were the most useful indicators for MME diagnosis. CONCLUSIONS: Ultrasonographic MME evaluations for MMPRT diagnosis showed relatively high sensitivity and specificity in patients with early knee OA. Dynamic ultrasonographic MME evaluation may lead to appropriate additional examinations, early diagnosis, and intervention for MMPRT in patients with early knee OA.

Large opening gaps, unstable hinge fractures, and osteotomy line below the safe zone cause delayed bone healing after open-wedge high tibial osteotomy.

PURPOSE: To evaluate bone formation in the osteotomy gap after open-wedge high tibial osteotomy (OWHTO), including after plate removal, and to investigate risk factors for delayed bone healing. METHODS: Ninety-three patients (102 knees) who underwent OWHTO without bone grafting were enrolled. The osteotomy gap was divided into the lateral hinge and the four zones on anteroposterior radiographs, and we defined the zone in which trabecular bone continuity could be observed as gap filling. Bone formation in the osteotomy gap was evaluated according to this definition at 3, 6, and 12 months postoperatively; at plate removal; and at the final follow-up (mean, 62.3 ± 30.2 months). We also investigated the risk factors for delayed bone healing. RESULTS: The lateral hinge united at 3 months postoperatively in 92 knees (90.2%). At 1 year postoperatively, 98 knees (96.1%) reached zone 1 and 92 knees (90.2%) reached zone 2. At plate removal, gap filling reached zone 2 in all cases and progressed further without loss of correction after plate removal. Opening width over 13.0 mm [odds ratio (OR): 1.61, P = 0.02], Takeuchi's classification type II lateral hinge fracture (OR: 20.4, P < 0.01), and osteotomy line below the safe zone (OR: 8.98, P < 0.01) significantly delayed bone formation after OWHTO. CONCLUSIONS: Gap filling progressed from lateral to medial after OWHTO without bone grafting and progressed further after plate removal. Large opening gaps, unstable hinge fractures, and osteotomy line below the safe zone cause delayed bone healing after OWHTO.

Greater body mass index and hip abduction muscle strength predict noncontact anterior cruciate ligament injury in female Japanese high school basketball players.

PURPOSE: This 3-year prospective study assessed risk factors for noncontact anterior cruciate ligament (ACL) injuries in female Japanese high school basketball players. Players suffering noncontact ACL injuries were assumed to demonstrate poorer hip abductor, knee flexor, and knee extensor muscle strength, as well as static balance, than those without injuries. METHODS: One hundred and ninety-five new female high school basketball players underwent baseline examinations for various parameters during their first year of high school. After the baseline data were collected, all ACL injuries occurring over the subsequent 3 years were recorded. The assessment parameters between the noncontact ACL injury group and the control group were compared. RESULTS: Of the 195 players, 24 were excluded due to pre-existing injuries present during the initial examination, quitting the basketball club during the follow-up period, or missing data. The remaining 171 players were observed for 3 years; unilateral noncontact ACL injuries were occurred in 12 players. Significantly lower general joint laxity and greater hip abductor strength were observed in the ACL injury group than in the control group. Body mass index (BMI) and hip abductor strength were significantly greater in the ACL injury group than in the control group, based on logistic regression analysis. CONCLUSIONS: Greater BMI and hip abductor muscle strength were independent risk factors for noncontact ACL injuries in female Japanese high school basketball players. Although performing complete screens may be difficult, attention should be given to ACL injuries, particularly in highly competitive players with strong muscles. LEVEL OF EVIDENCE: III.

Two-dimensional motion analysis of dynamic knee valgus identifies female high school athletes at risk of non-contact anterior cruciate ligament injury.

PURPOSE: Female athletes are at greater risk of non-contact ACL injury. Three-dimensional kinematic analyses have shown that at-risk female athletes have a greater knee valgus angle during drop jumping. The purpose of this study was to evaluate the relationship between knee valgus angle and non-contact ACL injury in young female athletes using coronal-plane two-dimensional (2D) kinematic analyses of single-leg landing. METHODS: Two hundred ninety-one female high school athletes newly enrolled in basketball and handball clubs were assessed. Dynamic knee valgus was analysed during single-leg drop jumps using 2D coronal images at hallux-ground contact and at maximal knee valgus. All subjects were followed up for 3 years for ACL injury. Twenty-eight (9.6%) of 291 athletes had ACL rupture, including 27 non-contact ACL injuries. The injured group of 27 knees with non-contact ACL injury was compared with a control group of 27 randomly selected uninjured knees. The relationship between initial 2D movement analysis results and subsequent ACL injury was investigated. RESULTS: Dynamic knee valgus was significantly greater in the injured group compared to the control group at hallux-ground contact (2.1 ± 2.4 vs. 0.4 ± 2.2 cm, P = 0.006) and at maximal knee valgus (8.3 ± 4.3 vs. 5.1 ± 4.1 cm, P = 0.007). CONCLUSION: The results of this study confirm that dynamic knee valgus is a potential risk factor for non-contact ACL injury in female high school athletes. Fully understanding the risk factors that increase dynamic knee valgus will help in designing more appropriate training and interventional strategies to prevent injuries in at-risk athletes. LEVEL OF EVIDENCE: Prognostic studies, Level II.

Poor static balance is a risk factor for non-contact anterior cruciate ligament injury.

BACKGROUND: This prospective study aimed to investigate the relationship between static balance and the incidence of non-contact anterior cruciate ligament (ACL) injury in female high school athletes. METHODS: This study included 276 female high school handball or basketball players. At the time of admission, each subject's static balance was measured with a gravicorder, and the incidence of non-contact ACL injury was investigated in the 3 years until the student graduated. The measured parameters of postural sway were locus length per time (the distance that a center of gravity of the foot pressure moves per second) and environmental area (AR: the area surrounded by the integumentary covering of the trace of the center of gravity). Twenty-seven players (9.8%) experienced an ACL injury during the 3-year observation period. Twenty-four injured players sustained a non-contact injury and three injured players sustained a contact injury. In this study, the three contact injury players were excluded. We compared the differences in the static balance between injured and uninjured players. RESULTS: The locus length per time was significantly longer in injured than in uninjured players (p = 0.046). Though there was no statistically significant difference between the two groups in AR (p = 0.190), AR tended to be larger in the ACL injured group. CONCLUSIONS: This result shows that poor static balance is a risk factor for non-contact ACL injury.

Ampicillin- and ampicillin/sulbactam-resistant Escherichia coli infection in a neonatal intensive care unit in Japan.

The incidence of ampicillin (ABPC)-resistant Escherichia coli (E. coli) infection in very low-birthweight infants has been increasing. The rate of ABPC/sulbactam (ABPC/SBT)-resistant E. coli in this population, however, is currently unknown. We encountered two cases of severe infection due to resistant E. coli and retrospectively studied the prevalence of ABPC- and ABPC/SBT-resistant E. coli in regular surveillance cultures obtained from all neonatal intensive care unit (NICU) patients between 2000 and 2013. The overall prevalence of ABPC-resistant E. coli was 39% (47/120), accounting for 63% of cases (32/51) between 2007 and 2013, compared with 22% (15/69) between 2000 and 2006. The prevalence of ABPC/SBT resistance was 17% (20/120), which was similar in both periods (16%, 8/51 vs 17%, 12/69). According to these results, not only ABPC, but also ABPC/SBT-resistant E. coli must be considered in the NICU.

A refined definition improves the measurement reliability of the tip-apex distance.

BACKGROUND: Tip-apex distance (TAD) is reported as a good predictor for cut-outs of lag screws and spiral blades in the treatment of intertrochanteric fractures, and surgeons are advised to strive for TAD within 20 mm. However, the femoral neck axis and the position of the lower limb in the lateral radiograph are not clearly defined and can lead to measurement errors. We propose a refined TAD by defining these factors. The objective of this study was to analyze the reliability of this refined TAD. METHODS: The radiographs of 130 prospective cases with unstable trochanteric fractures were used for the analysis of the refined TAD. The refined TAD was independently measured by 2 raters with clinical experience of more than 10 years (rater 1, 2) and 2 raters with much less clinical experience (rater 3, 4) after they received a training about the new measurement method. Intraclass correlation coefficient (ICC [2,4]) was calculated to assess the interrater reliability. RESULTS: The mean refined TADs were 18.2:18.4:18.2:18.2 mm for rater 1:2:3:4. There was a strong correlation among all four raters (ICC 0.998, (95% CI: 0.998, 0.999). CONCLUSIONS: Regardless of the clinical experience of raters, the refined TAD is a reliable tool and can be used to develop new TAD recommendations for predicting failure of fixation. Future studies with larger samples are needed to evaluate the predictive value of the refined TAD.

Risk factors for noncontact anterior cruciate ligament injury in female high school basketball and handball players: A prospective 3-year cohort study.

INTRODUCTION: The risk factors of noncontact anterior cruciate ligament (ACL) injury remain an enigma. The purpose of this study was to prospectively evaluate the risk factors for noncontact ACL injury in female high school basketball and handball players. MATERIALS AND METHODS: We conducted a 3-year prospective cohort study between 2009 and 2014, and it included 317 female high school athletes aged 15 years. At baseline, they underwent detailed examinations for various parameters that were documented during their first year of high school. The parameters assessed were height (cm), weight (kg), general joint laxity (points), navicular drop (mm), anterior laxity of the knee using the KT-1000 Knee Ligament Arthrometer (mm), angle of femoral anteversion (º), knee extensor/flexor muscle strength (Nm/kg), and hip abductor strength (Nm/kg). All ACL injuries that occurred during these 3 years were recorded. RESULTS: Of 317 players, 27 were excluded because they either had a history of ACL injury or could not complete the study. Thirty ACL tears occurred. Three of the ACL injuries were contact injuries, whereas the remaining 27 were noncontact injuries. Greater body weight (95% confidence interval [CI], 1.030-1.174; P = 0.004), a high hip abductor strength (95% CI, 1.462-4.827; P = 0.001), and small femoral anteversion (95% CI, 0.746-0.982; P = 0.027) were found to be risk factors in logistic regression analysis. CONCLUSION: Greater body weight, a high hip abductor strength, and small femoral anteversion were risk factors for noncontact ACL injury in female high school basketball and handball players.

Use of bisphosphonates for the treatment of stress fractures in athletes.

A literature review was performed to investigate the potential role of bisphosphonates for the treatment of stress fractures in athletes. Given the inhibitory action on osteoclast-mediated bone resorption, short-term suppression of bone remodeling using bisphosphonates could potentially treat stress fractures and prevent stress fractures from becoming regular fractures. To date, while there are some animal studies showing the scientific basis of bisphosphonates on stress fractures, there is still no conclusive evidence to prove any effect of bisphosphonates on stress fracture healing in humans. Further well-designed clinical trials should be carried out to establish their usefulness and safety. Until the results are available, it is prudent to limit the use of bisphosphonates for the treatment of stress fractures.

Clinical application of scaffolds for cartilage tissue engineering.

The purpose of this paper is to review the basic science and clinical literature on scaffolds clinically available for the treatment of articular cartilage injuries. The use of tissue-engineered grafts based on scaffolds seems to be as effective as conventional ACI clinically. However, there is limited evidence that scaffold techniques result in homogeneous distribution of cells. Similarly, few studies exist on the maintenance of the chondrocyte phenotype in scaffolds. Both of which would be potential advantages over the first generation ACI. The mean clinical score in all of the clinical literature on scaffold techniques significantly improved compared with preoperative values. More than 80% of patients had an excellent or good outcome. None of the short- or mid-term clinical and histological results of these tissue-engineering techniques with scaffolds were reported to be better than conventional ACI. However, some studies suggest that these methods may reduce surgical time, morbidity, and risks of periosteal hypertrophy and post-operative adhesions. Based on the available literature, we were not able to rank the scaffolds available for clinical use. Firm recommendations on which cartilage repair procedure is to be preferred is currently not known on the basis of these studies. Randomized clinical trials and longer follow-up periods are needed for more widespread information regarding the clinical effectiveness of scaffold-based, tissue-engineered cartilage repair.

Hip and Ankle Kinematics in Noncontact Anterior Cruciate Ligament Injury Situations: Video Analysis Using Model-Based Image Matching.

BACKGROUND: Detailed kinematic descriptions of real anterior cruciate ligament (ACL) injury situations are limited to the knee only. PURPOSE: To describe hip and ankle kinematics as well as foot position relative to the center of mass (COM) in ACL injury situations through use of a model-based image-matching (MBIM) technique. The distance between the projection of the COM on the ground and the base of support (BOS) (COM_BOS) normalized to the femur length was also evaluated. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten ACL injury video sequences from women's handball and basketball were analyzed. Hip and ankle joint kinematic values were obtained by use of MBIM. RESULTS: The mean hip flexion angle was 51° (95% CI, 41° to 63°) at initial contact and remained constant over the next 40 milliseconds. The hip was internally rotated 29° (95% CI, 18° to 39°) at initial contact and remained unchanged for the next 40 milliseconds. All of the injured patients landed with a heel strike with a mean dorsiflexion angle of 2° (95% CI, -9° to 14°), before reaching a flatfooted position 20 milliseconds later. The foot position was anterior and lateral to the COM in all cases. However, none of the results showed larger COM_BOS than 1.2, which has been suggested as a criterion for ACL injury risk. CONCLUSIONS: Hip kinematic values were consistent among the 10 ACL injury situations analyzed; the hip joint remained unchanged in a flexed and internally rotated position in the phase leading up to injury, suggesting that limited energy absorption took place at the hip. In all cases, the foot contacted the ground with the heel strike. However, relatively small COM_BOS distances were found, indicating that the anterior and lateral foot placement in ACL injury situations was not different from what can be expected in noninjury game situations.

On the iteration of coincidence summing correction for determination of gamma-ray intensities.

In order to determine the γ-ray emission intensities of nuclei far from the ß-stability line with HPGe detectors under large solid-angle geometry, coincidence summing corrections should be performed, even if full energy peak efficiencies of detectors are accurately measured with standard sources. Because the summing effects depend on decay schemes and emission intensities, the correction needs to be iterated several times starting from the initial values of intensities obtained directly from the measured peak counts of γ-rays. Considering (134)Cs, (154)Eu and (56)Co as typical examples, we discuss the number of iterations of summing correction required for self-consistency with respect to the total efficiencies of the detectors.

Psychological traits regarding competitiveness are related to the incidence of anterior cruciate ligament injury in high school female athletes.

BACKGROUND: The purpose of this study was to investigate the relationship between psychological competitive ability and the incidence of noncontact ACL injuries among high school female athletes. METHODS: A three-year prospective cohort study was conducted using 300 15-year-old high school female athletes with no previous injuries or symptoms in their lower limbs (106 handball players and 194 basketball players). At baseline, their psychological competitive abilities were assessed using a self-administered questionnaire-the Diagnostic Inventory of Psychological Competitive Ability (DIPCA.3). After the baseline examination was performed at high school entry, all players were prospectively followed for 36months to document any subsequent incidence of ACL injury, according to their coaches. An unpaired t-test with Welch's correction was performed to compare the differences in the psychological competitive abilities between the injured and uninjured players. RESULTS: Of the 300 players, 25 (8.3%) experienced a noncontact ACL injury during the three-year observation period. The injured players had significantly higher total DIPCA.3 scores for psychological competitive ability than the uninjured players (169.9±18.8 vs. 159.2±21.6, P=.036). Additionally, the injured players had significantly higher scores than the uninjured players in the following categories: aggressiveness, volition for self-realization, volition for winning, judgment, and cooperation. However, no significant differences were observed in patience, self-control, ability to relax, concentration, confidence, decision, and predictive ability. CONCLUSIONS: High psychological competitive ability was associated with the incidence of noncontact ACL injuries in high school female athletes. LEVEL OF EVIDENCE: Level II (prospective cohort study).

Determination of full-energy peak efficiency at the center position of a through-hole-type clover detector between 0.05 MeV and 3.2 MeV by source measurements and Monte Carlo simulations.

Full-energy peak efficiency at the center position of a through-hole-type clover detector was determined by the measurement of standard sources and by Monte Carlo simulation. The coincidence summing under the large-solid-angle condition was corrected using Monte Carlo calculation based on the specific decay scheme for (133)Ba, (152,154)Eu, and (56)Co. This allowed the peak efficiency to be extended from 0.05 MeV to 3.2 MeV with an approximate uncertainty of 3%.

Do design adaptations of a trochanteric nail make sense for Asian patients? Results of a multicenter study of the PFNA-II in Japan.

PURPOSE: Asian patients with osteoporosis suffer from an increased incidence of hip fracture and a potentially increased risk of fixation failure due to anatomical differences compared to Caucasians. To cope with these differences, an Asian size- and geometry-adapted Proximal Femoral Nail Antirotation (PFNA-II) was developed. The objective of this prospective multicenter study was to assess the risk of fracture fixation complications (FFCs), the occurrence of mismatch and the quality of life status of patients treated with the PFNA-II. PATIENTS AND METHODS: 176 Japanese patients with an isolated, unstable, closed trochanteric fracture were treated with the PFNA-II. Patients were prospectively screened for anticipated complications and classified accordingly; complications were centrally reviewed by a complication review board to avoid bias by the treating surgeon, and categorized using a standardized reporting system. Outcome measurements included the occurrence and evaluation of FFCs, the radiological assessment of mismatch and quality of life measured with the EQ-5D score. RESULTS: 3 Intraoperative and 15 postoperative complications were found in 16/176 patients. The risk of sustaining any intraoperative or postoperative FFC was 1.7% (3/176; 95% CI: 0.35-4.9) and 8% (14/176; 95% CI: 4.4-13), respectively. The most likely cause for FFCs was the "bone/fracture" factor (9/14 patients). Radiologically detectable contact of the implant with the inner cortex ("mismatch") was reported for 17/173 patients (10%). CONCLUSIONS: The reported complication risks and mismatches are reasonable for this patient cohort. The geometry- and size-adapted PFNA-II is relatively safe but requires standardized assessment in a larger target cohort.

Relative intensities of prompt γ-rays from the 35Cl(n,γ)36Cl reaction with thermal neutrons as secondary γ-ray intensity standards.

The relative intensities of 16 prompt γ-rays from the (35)Cl(n,γ)(36)Cl reaction with a thermal neutron were precisely determined as secondary γ-ray intensity standards with HPGe detectors. The detection efficiencies were calibrated from 0.2 to 10.8 MeV using the standard sources (152)Eu and (56)Co and the (14)N(n,γ)(15)N reaction. We performed appropriate analyses for the evaluation of doublet peaks, subtraction of mixing with escape γ-rays and other corrections; consequently, the values were determined within 1% accuracy. Relative intensities in the range of 0.7 to 8.6 MeV are proposed as reliable secondary standards for 16 γ-rays.

Cervical pachymeningeal hypertrophy as the initial and cardinal manifestation of mucopolysaccharidosis type I in monozygotic twins with a novel mutation in the alpha-L-iduronidase gene.

We describe a pair of monozygotic twins with an attenuated form of mucopolysaccharidosis type I (MPS-I). At age 24, they both developed cervical myelopathy as a cardinal manifestation. They each also had mild valve abnormalities and both inguinal and umbilical hernia, however, other characteristic features of MPS-I were absent or very mild. Magnetic resonance imaging revealed the cervical cord compressed by pachymeningeal hypertrophy. Surgery with dural plasty and laminoplasty resulted in decompression of the cervical cord with clinical improvement, revealing marked thickening of the dura mater. Both patients showed a marked decrease of alpha-L-iduronidase (IDUA) activity with c.252insC (p.P55fsX62; known) and c.1209C>A (p.T374N; novel) mutations of the IDUA gene (IDUA). Patients with MPS-I have been reported to present with various clinical phenotypes and severities even if they have identical mutations of IDUA. The quite similar, unique phenotype in monozygotic twins suggests that not only IDUA mutation but also other genetic factors than IDUA markedly influence the clinical manifestations of MPS-I.

Mechanisms for noncontact anterior cruciate ligament injuries: knee joint kinematics in 10 injury situations from female team handball and basketball.

BACKGROUND: The mechanism for noncontact anterior cruciate ligament injury is still a matter of controversy. Video analysis of injury tapes is the only method available to extract biomechanical information from actual anterior cruciate ligament injury cases. PURPOSE: This article describes 3-dimensional knee joint kinematics in anterior cruciate ligament injury situations using a model-based image-matching technique. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Ten anterior cruciate ligament injury video sequences from women's handball and basketball were analyzed using the model-based image-matching method. RESULTS: The mean knee flexion angle among the 10 cases was 23° (range, 11°-30°) at initial contact (IC) and had increased by 24° (95% confidence interval [CI], 19°-29°) within the following 40 milliseconds. The mean valgus angle was neutral (range, -2° to 3°) at IC, but had increased by 12° (95% CI, 10°-13°) 40 milliseconds later. The knee was externally rotated 5° (range, -5° to 12°) at IC, but rotated internally by 8° (95% CI, 2°-14°) during the first 40 milliseconds, followed by external rotation of 17° (95% CI, 13°-22°). The mean peak vertical ground-reaction force was 3.2 times body weight (95% CI, 2.7-3.7), and occurred at 40 milliseconds after IC (range, 0-83). CONCLUSION: Based on when the sudden changes in joint angular motion and the peak vertical ground-reaction force occurred, it is likely that the anterior cruciate ligament injury occurred approximately 40 milliseconds after IC. The kinematic patterns were surprisingly consistent among the 10 cases. All players had immediate valgus motion within 40 milliseconds after IC. Moreover, the tibia rotated internally during the first 40 milliseconds and then external rotation was observed, possibly after the anterior cruciate ligament had torn. These results suggest that valgus loading is a contributing factor in the anterior cruciate ligament injury mechanism and that internal tibial rotation is coupled with valgus motion. Prevention programs should focus on acquiring a good cutting and landing technique with knee flexion and without valgus loading of the knee.

Effect of heat shock preconditioning on ROS scavenging activity in rat skeletal muscle after downhill running.

The mechanisms of the protective effect conferred by heat shock preconditioning (HS) are currently unknown. The purpose of this study was to determine the effect of HS on muscle injury after downhill running and to address the mechanism of the effect. Female Wistar rats were assigned to three groups: HS, downhill running (E), and downhill running after heat shock preconditioning (HS + E). The HS and HS + E rats were placed in a heat chamber for 60 min (ambient temperature 42 +/- 1.0 degrees C) 48 h before downhill running. Reactive oxygen species (ROS) scavenging activity was determined by electron spin resonance (ESR), and heat shock protein 72 (HSP72) mRNA expression was measured in rat quadriceps femoris. Leukocyte infiltration and degenerated muscle fibers were determined histopathologically. ROS scavenging activity significantly increased at 3 days after HS (151 +/- 18%) and HSP72 mRNA expression increased immediately after HS (1750 +/- 1914%). No decrease in ROS scavenging activity was observed in the HS + E rats at 2 days after exercise compared with the E rats (102 +/- 9% vs. 79 +/- 5%). Degenerated muscle fibers in HS + E rats were significantly less than in E rats at 2, 3, and 7 days after exercise (0.8 +/- 1.0 vs. 2.8 +/- 1.6, 0.8 +/- 1.0 vs. 1.8 +/- 1.6, 0 vs. 0.3 +/- 0.6, respectively). These data demonstrated that HS can reduce muscle injury after downhill running, and this effect may be mediated by increased ROS scavenging activity. Furthermore, HS may protect the antioxidant defense system in skeletal muscle by enhancing the adaptive HSP72 mRNA response.