Changes in Intraset Repetitions in Reserve Prediction Accuracy During Six Weeks of Bench Press Training in Trained Men.

In this study we investigated whether the accuracy of intraset repetitions in reserve (RIR) predictions changes over time. Nine trained men completed three bench press training sessions per week for 6 weeks (following a 1-week familiarization). The final set of each session was performed until momentary muscular failure, with participants verbally indicating their perceived 4RIR and 1RIR. RIR prediction errors were calculated as raw differences (RIRDIFF), with positive and negative values indicating directionality, and absolute RIRDIFF (absolute value of raw RIRDIFF) indicating error scores. We constructed mixed effect models with time (i.e., session) and proximity to failure as fixed effects, repetitions as a covariate, and random intercepts per participant to account for repeated measures, with statistical significance set at p ≤ .05. We observed a significant main effect for time on raw RIRDIFF (p < .001), with an estimated marginal slope of -.077 repetitions, indicating a slight decrease in raw RIRDIFF over time. Further, the estimated marginal slope of repetitions was -.404 repetitions, indicating a decrease in raw RIRDIFF as more repetitions were performed. There were no significant effects on absolute RIRDIFF. Thus, RIR rating accuracy did not significantly improve over time, though there was a greater tendency to underestimate RIR in later sessions and during higher repetition sets.

Methods for Controlling and Reporting Resistance Training Proximity to Failure: Current Issues and Future Directions.

Resistance training variables such as volume, load, and frequency are well defined. However, the variable proximity to failure does not have a consistent quantification method, despite being defined as the number of repetitions in reserve (RIR) upon completion of a resistance training set. Further, there is between-study variability in the definition of failure itself. Studies have defined failure as momentary (inability to complete the concentric phase despite maximal effort), volitional (self-termination), or have provided no working definition. Methods to quantify proximity to failure include percentage-based prescription, repetition maximum zone training, velocity loss, and self-reported RIR; each with positives and negatives. Specifically, applying percentage-based prescriptions across a group may lead to a wide range of per-set RIR owing to interindividual differences in repetitions performed at specific percentages of 1 repetition maximum. Velocity loss is an objective method; however, the relationship between velocity loss and RIR varies set-to-set, across loading ranges, and between exercises. Self-reported RIR is inherently individualized; however, its subjectivity can lead to inaccuracy. Further, many studies, regardless of quantification method, do not report RIR. Consequently, it is difficult to make specific recommendations for per-set proximity to failure to maximize hypertrophy and strength. Therefore, this review aims to discuss the strengths and weaknesses of the current proximity to failure quantification methods. Further, we propose future directions for researchers and practitioners to quantify proximity to failure, including implementation of absolute velocity stops using individual average concentric velocity/RIR relationships. Finally, we provide guidance for reporting self-reported RIR regardless of the quantification method.

Thoracic and lumbar fractures associated with skiing and snowboarding injuries according to the AO Comprehensive Classification.

BACKGROUND: The incidence of spinal fractures varies from 1% to 17% in alpine skiing injuries. Distinctions have been made regarding the differences in the mechanisms of injury and fracture types between skiing and snowboarding. Although fracture patterns have been described, there have not been any detailed descriptions of the specific fracture types and subgroups. PURPOSE: To address the patterns of spinal fractures associated with these sports and to determine the incidence of various fracture groups and subgroups as well as to determine whether the fracture patterns differ between skiing and snowboarding injuries. STUDY DESIGN: Descriptive epidemiology study. METHODS: This is a retrospective review of thoracic and lumbar spinal fractures associated with either skiing or snowboarding over a period of 5 years. The injuries were classified according to the AO Comprehensive Classification. In addition, isolated transverse process fractures and isolated spinous process fractures were included. Cervical spine fractures were excluded from this study. RESULTS: There were a total of 119 patients with thoracic and lumbar fractures that were identified after 1,283,348 skiing/snowboarding days. There were a total of 146 fractures, of which 114 were classified according to the AO Comprehensive Classification, with the remaining fractures (n = 32) consisting of isolated transverse or spinous process fractures. The preponderance of these injuries (94.7%) was compression injuries. Burst fractures (A3.1 and A3.2) made up 23%, and simple compression fractures (A1.1, A1.2, and A1.3) made up 71% of the total. Distraction injuries composed only 4.4%, and rotation injuries composed 0.9% of the total. The snowboarders incurred only compression fractures, whereas the 5 distraction injuries and the 1 rotational injury were noted only in the skier population. There were no patients with neurological deficits in this review. Fourteen skiers (14%) and 10 snowboarders (8%) were found to have isolated transverse process fractures. All 6 isolated spinous process fractures (4% of all fractures) were in the thoracic spine. CONCLUSION: Thoracic and lumbar fractures caused by skiing and snowboarding are mainly stable injuries, composed of either compression fractures, mostly simple compression injuries, or isolated transverse and spinous process fractures. Neurological injury was not seen in this study.

Physical and monetary costs associated with autogenous bone graft harvesting.

Although autogenous iliac bone is frequently used for bone graft, many well-documented complications are associated with this procedure-including chronic pain; nerve, arterial, and ureteral injury; herniation of abdominal contents; sacroiliac joint instability; pelvic fractures; hematoma; and infection. An understanding of the morbidities associated with bone graft harvesting and of the strategies for avoiding them is imperative for surgeons using this grafting source. In addition, although synthetic grafting materials are considered relatively expensive compared with autogenous sources, the majority of physicians are unaware of the actual direct and indirect costs associated with autogenous bone graft harvesting. Contemporary allograft and synthetic grafting composites are being developed to optimize and surpass the native qualities of autogenous sources (ie, osteogenesis, osteoinductivity, osteoconductivity). Careful comparison of the cost of these alternative sources with the physical and monetary costs of autogenous bone graft will undoubtedly make allograft, recombinant, synthetic graft composites the logical choice in the very near future.

Differences in femoral notch anatomy between men and women: a magnetic resonance imaging study.

BACKGROUND: Research has shown that variations in femoral intercondylar notch morphometry may be a predisposing factor for noncontact anterior cruciate ligament injury. HYPOTHESIS: There are anatomic differences in the anterior cruciate ligament and femoral notch between men and women. STUDY DESIGN: Descriptive anatomic study. METHODS: Using magnetic resonance imaging, we performed a three-dimensional analysis of the femoral intercondylar notch morphometry to look for differences in femoral notch and anterior cruciate ligament volumes between men and women. Axial plane magnetic resonance imaging scans were performed on 96 knees in 48 asymptomatic subjects. Digital measurements were taken of femoral notch area, anterior cruciate ligament area, notch width, and bicondylar width, within defined parameters of the femoral notch. The notch and anterior cruciate ligament volumes were then calculated. Analysis of variance was performed using sex, height, and weight as covariates. RESULTS: The volume of the femoral notch was found to be statistically smaller in women compared with men; this difference was primarily related to height. A similar relationship was found for anterior cruciate ligament volume. A statistically significant correlation was found between femoral notch volume and anterior cruciate ligament volume; patients with smaller notches also had smaller anterior cruciate ligaments. CONCLUSIONS: Our results suggest that there is a difference in femoral notch and anterior cruciate ligament volume between men and women, which, in turn, is related to differences in height and weight.