Journal of Sports Medicine最新文献

Background. Hamstring injuries continue to affect active individuals and although inadequate muscle extensibility remains a commonly accepted factor, little is known about the most effective method to improve flexibility. Purpose. To determine if an isolated neurodynamic sciatic sliding technique would improve hamstring flexibility to a greater degree than stretching or a placebo intervention in asymptomatic subjects with short hamstring syndrome (SHS). Study Design. Randomized double-blinded controlled trial. Methods. One hundred and twenty subjects with SHS were randomized to 1 of 3 groups: neurodynamic sliding, hamstring stretching, and placebo control. Each subject's dominant leg was measured for straight leg raise (SLR) range of motion (ROM) before and after interventions. Data were analyzed with a 3 × 2 mixed model ANOVA followed by simple main effects analyses. Results. At the end of the study, more ROM was observed in the Neurodynamic and Stretching groups compared to the Control group and more ROM in the Neurodynamic group compared to Stretching group. Conclusion. Findings suggest that a neurodynamic sliding technique will increase hamstring flexibility to a greater degree than static hamstring stretching in healthy subjects with SHS. Clinical Relevance. The use of neurodynamic sliding techniques to improve hamstring flexibility in sports may lead to a decreased incidence in injuries; however, this needs to be formally tested.

Chronological aging is associated with a decrease in skeletal muscle mass and bone mineral density, an increase in fat mass, frequency of falls and fractures, and the likelihood of obesity, diabetes, and coronary heart disease. Resistance exercise has been shown to counter all of these effects of aging and, in turn, reduce the risk of all-cause mortality. However, variables such as volume and frequency have become contentious issues, with recent publications suggesting that similar physiological adaptations are possible with both high- and low-volume approaches. The aim of this research was to consider strength increases as a result of brief, infrequent resistance exercise. The present study offers data from 33 (14 male and 19 female) older adults (M = 55 years) who underwent brief (<15 minutes per exercise session), infrequent (2×/week), resistance exercise to a high intensity of effort (6-repetition maximum) at a controlled repetition duration (10 seconds concentric : 10 seconds eccentric) on 5 resistance machines (chest press, leg press, pull-down, seated row, and overhead press). Data is presented for training interventions of 12 weeks (male) and 19 weeks (female). Significant strength increases were identified for all exercises. With the detailed health benefits obtainable, the present study suggests that resistance exercise can be efficacious in much smaller volumes than previously considered.

The aim of this study was to examine the effect of acute Rhodiola rosea (R. rosea) ingestion on substrate utilisation, mood state, RPE, and exercise affect. Ten males (mean age ± S.D. = 26 ± 6 years) completed two 30-minute cycling trials at an intensity of 70% of [Formula: see text] following ingestion of either 3 mg·kg(-1) body mass of R. rosea or placebo using a double-blind, crossover design. During exercise, heart rate and RPE were recorded. Participants completed measures of mood state and exercise affect before and after exercise. Expired air samples were taken during exercise to determine substrate utilisation. Repeated measures analysis of variance indicated that RPE was significantly lower at 30 minutes into exercise versus placebo (P = 0.003). Perceptions of arousal (P = 0.05) and pleasure were significantly higher after exercise with R. rosea compared to placebo (P = 0.003). Mood state scores for vigor were also higher in R. rosea condition compared to placebo (P = 0.008). There were no significant differences in energy expenditure, carbohydrate, or fat oxidation between conditions (P > 0.05). Ingestion of R. rosea favourably influenced RPE and exercise affect without changes in energy expenditure or substrate utilization during 30-minute submaximal cycling performance.

Background. The purpose of this study was to compare outcomes of medial patellofemoral ligament (MPFL) repair or reconstruction. Methods. Fourteen knees that underwent MPFL repair and nine (F5, M4) knees that underwent reconstruction at our institution were evaluated for objective and subjective outcomes. The mean age at operation was 20.1 years for repair and 19.8 years for reconstruction. All patients had a minimum of 2 years of follow-up (range: 24-75 months). Patient subjective outcomes were obtained using the International Knee Documentation Committee (IKDC) and Kujala patellofemoral subjective evaluations, as well as Visual Analog (VAS) and Tegner Activity Scales. Bilateral isometric quadriceps strength and vastus medialis obliquus (VMO) and vastus lateralis (VL) surface EMG were measured during maximal isometric quadriceps contractions at 30° and 60° of flexion. Results. There were no redislocations in either group. There was no difference in IKDC (P = 0.16), Kujala (P = 0.43), Tegner (P = 0.12), or VAS (P = 0.05) scores at follow-up. There were no differences between repair and reconstruction in torque generation of the involved side at 30° (P = 0.96) and 60° (P = 0.99). In addition, there was no side to side difference in torque generation or surface EMG activation of VL or VMO. Conclusions. There were minimal differences found between patients undergoing MPFL repair and MPFL reconstruction for the objective and subjective evaluations in this study.

The effects of cooling on neuromuscular function and performance during gait are not fully examined. The purpose of this study was to investigate the effects of local cooling for 20 min in cold water at 10°C in a climate chamber also at 10°C on maximal isometric force and electromyographic (EMG) activity of the lower leg muscles. Gait ground reaction forces (GRFs) were also assessed. Sixteen healthy university students participated in the within subject design experimental study. Isometric forces of the tibialis anterior (TA) and the gastrocnemius medialis (GM) were measured using a handheld dynamometer and the EMG was recorded using surface electrodes. Ground reaction forces during gait and the required coefficient of friction (RCOF) were recorded using a force plate. There was a significantly reduced isometric maximum force in the TA muscle (P < 0.001) after cooling. The mean EMG amplitude of GM muscle was increased after cooling (P < 0.003), indicating that fatigue was induced. We found no significant changes in the gait GRFs and RCOF on dry and level surface. These findings may indicate that local moderate cooling 20 min of 10°C cold water, may influence maximal muscle performance without affecting activities at sub-maximal effort.

The objective was to illuminate the experience of injuries and the process of injury reporting within the Swedish skydiving culture. Data contained narrative interviews that were subsequently analyzed with content analysis. Seventeen respondents (22-44 years) were recruited at three skydiving drop zones in Sweden. In the results injury events related to the full phase of a skydive were described. Risk of injury is individually viewed as an integrated element of the recreational activity counterbalanced by its recreational value. The human factor of inadequate judgment such as miscalculation and distraction dominates the descriptions as causes of injuries. Organization and leadership act as facilitators or constrainers for reporting incidents and injuries. On the basis of this study it is interpreted that safety work and incident reporting in Swedish skydiving may be influenced more by local drop zone culture than the national association regulations. Formal and informal hierarchical structures among skydivers seem to decide how skydiving is practiced, rules are enforced, and injuries are reported. We suggest that initial training and continuing education need to be changed from the current top-down to a bottom-up perspective, where the individual skydiver learns to see the positive implications of safety work and injury reporting.

Functional popliteal artery entrapment syndrome (PAES) is an important and possibly underrecognized cause of exertional leg pain (ELP). As it is poorly understood, it is at risk of misdiagnosis and mismanagement. The features indicative of PAES are outlined, as it can share features with other causes of ELP. Investigating functional PAES is also fraught with potential problems and if it is performed incorrectly, it can result in false negative and false positive findings. A review of the current vascular investigations is provided, highlighting some of the limitations standard tests have in determining functional PAES. Once a clinical suspicion for PAES is satisfied, it is necessary to further distinguish the subcategories of anatomical and functional entrapment and the group of asymptomatic occluders. When definitive entrapment is confirmed, it is important to identify the level of entrapment so that precise intervention can be performed. Treatment strategies for functional PAES are discussed, including the possibility of a new, less invasive intervention of guided Botulinum toxin injection at the level of entrapment as an alternative to vascular surgery.

Purpose. In this study, the early and midterm clinical and radiological results of the anterior cruciate ligament (ACL) reconstruction surgery with or without the use of platelet rich plasma (PRP) focusing on the tunnel-widening phenomenon are evaluated. Methods. This is a double blind, prospective randomized study. 51 patients have completed the assigned protocol. Recruited individuals were divided into two groups: a group with and a group without the use of PRPs. Patients were assessed on the basis of MRI scans, which were performed early postoperatively and repeated at least one-year postoperatively. The diameter was measured at the entrance, at the bottom, and at the mid distance of the femoral tunnel. Results. Our study confirmed the existence of tunnel widening as a phenomenon. The morphology of the dilated tunnels was conical in both groups. There was a statistical significant difference in the mid distance of the tunnels between the two groups. This finding may support the role of a biologic response secondary to mechanical triggers. Conclusions. The use of RPRs in ACL reconstruction surgery remains a safe option that could potentially eliminate the biologic triggers of tunnel enlargement. The role of mechanical factors, however, remains important.

Currently, little is known about the length of time required to rehabilitate patients from stress fractures and their return to preinjury level of physical activity. Previous studies have looked at the return to sport in athletes, in a general population, where rehabilitation is not as controlled as within a captive military population. In this study, a longitudinal prospective epidemiological database was assessed to determine the incidence of stress fractures and the time taken to rehabilitate recruits to preinjury stage of training. Findings demonstrated a background prevalence of 5% stress fractures in Royal Marine training; femoral and tibial stress fractures take 21.1 weeks to return to training with metatarsal stress fractures being the most common injury taking 12.2 weeks. Rehabilitation from stress fractures accounts for 814 weeks of recruit rehabilitation time per annum. Stress fracture incidence is still common in military training; despite this stress fracture recovery times remain constant and represent a significant interruption in training. It takes on average 5 weeks after exercise specific training has restarted to reenter training at a preinjury level, regardless of which bone has a stress fracture. Further research into their prevention, treatment, and rehabilitation is required to help reduce these burdens.

Iliotibial band syndrome (ITBS) is a common injury in runners and other long distance athletes with the best management options not clearly established. This review outlines both the conservative and surgical options for the treatment of iliotibial band syndrome in the athletic population. Ten studies met the inclusion criteria by focusing on the athletic population in their discussion of the treatment for iliotibial band syndrome, both conservative and surgical. Conservative management consisting of a combination of rest (2-6 weeks), stretching, pain management, and modification of running habits produced a 44% complete cure rate, with return to sport at 8 weeks and a 91.7% cure rate with return to sport at 6 months after injury. Surgical therapy, often only used for refractory cases, consisted of excision or release of the pathologic distal portion of the iliotibial band or bursectomy. Those studies focusing on the excision or release of the pathologic distal portion of the iliotibial band showed a 100% return to sport rate at both 7 weeks and 3 months after injury. Despite many options for both surgical and conservative treatment, there has yet to be consensus on one standard of care. Certain treatments, both conservative and surgical, in our review are shown to be more effective than others; however, further research is needed to delineate the true pathophysiology of iliotibial band syndrome in athletes, as well as the optimal treatment regimen.