Epidemiology of weight training-related injuries presenting to United States emergency departments, 1990 to 2007

Lower Body Weightlifting Injuries Treated in United States Emergency Departments from 2012-2021

Weightlifting has become an increasingly popular form of exercise that has been shown to have many health benefits but can be dangerous if performed improperly. The objective of this study was to describe the epidemiology of lower body weightlifting injuries in the United States. The National Electronic Injury Surveillance System database was queried from January 1, 2012, to December 31, 2021, for lower body injuries related to using weightlifting equipment. Demographics, diagnosis, disposition, and mechanism of injury (MOI) were analyzed. There were 7,773 lower extremity weightlifting injuries identified from 2012-2021, giving a national estimate of 311,842 injuries. The most common MOI was dropped weight (n=1785, 22.96%). Deadlifts were the most cited exercise that led to lower extremity injury (n=503, 6.47%). Males were more likely than females to be injured (76% males vs. 24% females; p<0.001), especially by compound movements with free weights including squats (79.63% males vs. 19.96% females, p<0.03) and deadlifts (83.89% males vs. 16.10% females, p<0.001). Nearly all injuries were treated as outpatient but those admitted to the hospital were significantly older than those treated as outpatients (38.0 years vs. 31.2 years, p<0.05). Weightlifting carries a high risk of injury due to the intensity and technique required for the different movements involved.

Prevalence, and types of overuse injuries in gym centers: A cross-sectional study in Saudi Arabia

Physical activity has numerous health benefits, enhancing overall wellbeing. However, it can also lead to injuries, impeding exercise capacity and hindering work. Limited knowledge exists about the prevalence of overuse gym injuries and whether they vary across different gym activities. This study aims to estimate sport injuries at fitness centers in Saudi Arabia, comparing injuries between various activities and session durations. This is a cross-sectional, questionnaire-based study surveyed regular gym-goers in Saudi Arabia with overuse injuries. The online survey, distributed through social media apps, collected data using a validated Google form questionnaire. Questioanire consists of 3 parts. First part of the questionnaire included demographic characteristics of participants. Second part contains characteristics related to gym as gym session's duration, frequency of attending gym per week, sport types, type of injuries and site of injuries. Third part contains Oslo Sports Trauma Research Centre (OSTRC) Overuse injury questionnaire that included 4 questions about difficulties in participation, reduction of training, affection of performance and symptoms. Study included 1012 participants, majority male (76.2%), with age range of 18 to 50 years, and significant proportion falling between 26 and 30 years (52.6%). Majority of participants were from Central Province (42.9%). Gym sessions typically lasted 1 to 2 hours (68.3%), and most common attendance frequency was 4 days/week (39.6%). Common injury sites were shoulder (25.2%), knee (20.2%), and lower back (17.7%). Bodybuilding (50.6%), running (45.8%), and weightlifting/powerlifting (45.1%) were predominant sports. Strain/muscle rupture/tear (35.70%) and muscle cramps/spasm (19.3%) were commonest injury types. Longer gym sessions (>2 hours) were associated with higher prevalence of strain/muscle rupture/tear, dislocation, and subluxation (P < .001). Shorter sessions (<1 hour) had higher prevalence of muscle cramps/spasm and contusion/hematoma/bruise (P < .001). Gym sessions lasting 1 to 2 hours had high prevalence in tendinosis/tendinopathy. Strain/muscle rupture/tear was significantly higher in bodybuilding, weightlifting/powerlifting, swimming, cycling, and running. Tendinosis/tendinopathy was higher in crossfit. (OSTRC) Overuse injury questionnaire revealed decreased participation, training volume, performance, and increased pain with longer gym sessions. In conclusion, gym-related injuries are common, with bodybuilding and running being prevalent activities. Preventative measures should be taken, and individuals are advised to undergo a physical and medical examination before engaging in physical activity at fitness centers.

A National 20-year Analysis of Weight Lifting-related Injuries and Fractures Among Adolescents

BACKGROUND

Increasing strength through weightlifting has become a core component of competitive sports training, recreational exercise programs, and school physical education classes. Although many health benefits exist, there is concern for injury, especially with improper supervision and accelerated progression of training loads. Though organizations have advocated safe training practices, trends in the national health burden of injuries, specifically fractures, associated with weightlifting in the adolescent population have not been investigated.

METHODS

The National Electronic Injury Surveillance System database was queried between 2002 and 2021 for patients aged 11 to 21 years presenting to US Emergency Departments with weight lifting-related injuries. The narrative component of each case identified was analyzed to include only patients noted to be using weightlifting equipment or free weights at the time of injury. Estimates and analyses were performed with 95% CIs.

RESULTS

Although there has been some variability in weight lifting-related injuries, the incidence remained roughly constant over the 20 years ( R2 =0.0364). 14,497 cases were identified, reflecting a national estimate of 540,986 total injuries and an annual estimate of 27,049 injuries. Most injuries occurred among 15-to-18-year olds (44.1%±1.6%) and 19-to-21-year olds (38.3%±2.0%). The most common injuries were sprain/strain (36.7%±1.3%), contusion/abrasion (15.7%±0.7%), and fracture (9.9%±0.3%). There were 53,813 estimated fractures, giving an annual incidence of 2,691 fractures. As a portion of all injuries, the number of fractures decreased significantly as patients got older, accounting for 26.8%±3.3% at age 11 and only 8.3%±0.9% at age 21 ( R2 =0.6626). Fingers (37.1%±1.8%) and toes (27.9%±1.4%) were the most fractured body parts. Overall, fractures mainly occurred either at school (25.3%±2.0%) or places of recreation (24.7%±2.2%).

CONCLUSIONS

Despite the guidelines to improve safety, the national health burden of weight lifting-related injuries among adolescents has remained constant over the past 20 years. Given that most of the fractures occur in the distal extremities, such as toes and fingers, at school and places of recreation, there may be an opportunity to promote safer weightlifting practices and the development of weightlifting equipment with in-built safety mechanisms, especially at gyms and schools.

LEVEL OF EVIDENCE

Level III-prognostic.

Minimalist Training: Is Lower Dosage or Intensity Resistance Training Effective to Improve Physical Fitness? A Narrative Review

BACKGROUND

Findings from original research, systematic reviews, and meta-analyses have demonstrated the effectiveness of resistance training (RT) on markers of performance and health. However, the literature is inconsistent with regards to the dosage effects (frequency, intensity, time, type) of RT to maximize training-induced improvements. This is most likely due to moderating factors such as age, sex, and training status. Moreover, individuals with limited time to exercise or who lack motivation to perform RT are interested in the least amount of RT to improve physical fitness.

OBJECTIVES

The objective of this review was to investigate and identify lower than typically recommended RT dosages (i.e., shorter durations, lower volumes, and intensity activities) that can improve fitness components such as muscle strength and endurance for sedentary individuals or beginners not meeting the minimal recommendation of exercise.

METHODS

Due to the broad research question involving different RT types, cohorts, and outcome measures (i.e., high heterogeneity), a narrative review was selected instead of a systematic meta-analysis approach.

RESULTS

It seems that one weekly RT session is sufficient to induce strength gains in RT beginners with < 3 sets and loads below 50% of one-repetition maximum (1RM). With regards to the number of repetitions, the literature is controversial and some authors report that repetition to failure is key to achieve optimal adaptations, while other authors report similar adaptations with fewer repetitions. Additionally, higher intensity or heavier loads tend to provide superior results. With regards to the RT type, multi-joint exercises induce similar or even larger effects than single-joint exercises.

CONCLUSION

The least amount of RT that can be performed to improve physical fitness for beginners for at least the first 12 weeks is one weekly session at intensities below 50% 1RM, with < 3 sets per multi-joint exercise.

Effects of blood flow restriction training on muscle fitness and cardiovascular risk of obese college students

Purpose: The aim of this study was to investigate the effect of blood flow restriction (BFR) combined with low-intensity resistance training (RT) on cardiovascular risk factors in obese individuals. Methods: Twenty-six male obese college students were recruited and randomly assigned to a control group (CON, n = 8), a low-intensity RT group (RT, n = 9), and a combined BFR training and low-intensity RT group (BFRT, n = 9). Results: The subjects in BFRT group showed significant reductions in body fat percentage and waist-to-hip ratio and a significant increase in lean mass and muscle mass; the peak torque, peak power, and endurance ratio of knee extensors and elbow flexors were significantly upregulated; the root mean square (RMS) for the medial femoral muscle, lateral femoral muscle and biceps significantly increased; the diastolic blood pressure (DBP) showed a significant decrease. The BFRT group also showed significant up-regulations in RMS of the difference between the adjacent R-R intervals (RMSSD), high-frequency power (HF) of parasympathetic modulatory capacity, the standard deviation of R-R intervals (SDNN) of overall heart rate variability (HRV) changes and low-frequency power (LF) of predominantly sympathetic activity. In addition, glycated hemoglobin (HbA1C), insulin resistance index (HOMA-IR) and fasting blood glucose (FBG) were all significantly downregulated in BFRT group. In parallel, low-density lipoprotein (LDL-C) significantly reduced while high-density lipoprotein (HDL-C) significantly increased in BFRT group. Conclusion: BFR combined with low-intensity RT training effectively improved body composition index, increased muscle mass, improved neuromuscular activation, enhanced muscle strength and endurance, which in turn improved abnormal glucolipid metabolism and enhanced cardiac autonomic regulation.

Effect of free-weight vs. machine-based strength training on maximal strength, hypertrophy and jump performance - a systematic review and meta-analysis

BACKGROUND

The effectiveness of strength training with free-weight vs. machine equipment is heavily debated. Thus, the purpose of this meta-analysis was to summarize the data on the effect of free-weight versus machine-based strength training on maximal strength, jump height and hypertrophy.

METHODS

The review was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, and the systematic search of literature was conducted up to January 1st, 2023. Studies that directly compared free-weight vs. machine-based strength training for a minimum of 6 weeks in adults (18-60 yrs.) were included.

RESULTS

Thirteen studies (outcomes: maximal strength [n = 12], jump performance [n = 5], muscle hypertrophy [n = 5]) with a total sample of 1016 participants (789 men, 219 women) were included. Strength in free-weight tests increased significantly more with free-weight training than with machines (SMD: -0.210, CI: -0.391, -0.029, p = 0.023), while strength in machine-based tests tended to increase more with machine training than with free-weights (SMD: 0.291, CI: -0.017, 0.600, p = 0.064). However, no differences were found between modalities in direct comparison (free-weight strength vs. machine strength) for dynamic strength (SMD: 0.084, CI: -0.106, 0.273, p = 0.387), isometric strength (SMD: -0.079, CI: -0.432, 0.273, p = 0.660), countermovement jump (SMD: -0.209, CI: -0.597, 0.179, p = 0.290) and hypertrophy (SMD: -0.055, CI: -0.397, 0.287, p = 0.751).

CONCLUSION

No differences were detected in the direct comparison of strength, jump performance and muscle hypertrophy. Current body of evidence indicates that strength changes are specific to the training modality, and the choice between free-weights and machines are down to individual preferences and goals.

Chronic Lower Back Pain in Weight Lifters: Epidemiology, Evaluation, and Management

» Chronic lower back pain (LBP) is common in both nonathletes and weight lifters, but the diagnosis and treatment should be approached differently in these 2 populations based on the unique movement patterns causing the pain.» Injury rates of weight lifters are far less than those of contact sports, ranging from 1.0 to 4.4 injuries per 1,000 workout hours. However, the lower back was consistently one of the top 2 injury sites for weight lifters, accounting for anywhere from 23% to 59% of all injuries. LBP was most often associated with the squat or deadlift.» Guidelines for evaluating general LBP are applicable to weight lifters, including a thorough history and physical examination. However, the differential diagnosis will change based on the patient's lifting history. Of the many etiologies of back pain, weight lifters are most likely to be diagnosed with muscle strain or ligamentous sprain, degenerative disk disease, disk herniation, spondylolysis, spondylolisthesis, or lumbar facet syndrome.» Traditional recommended therapies include nonsteroidal anti-inflammatory drugs, physical therapy, and activity modification, which are often insufficient to resolve pain and prevent injury recurrence. Because most athletes will want to continue to lift weights, lifting-specific behavior modifications focused on improved technique and correcting mobility and muscular imbalances are important aspects of management in this patient population.

Which resistance training is safest to practice? A systematic review

BACKGROUND

The combination of resistance training (RT) and aerobic training is believed to achieve the best effects. Several different aerobic training methods have emerged in combination with or as a substitute for traditional RT. This study wished to verify which RT is safest in terms of injury prevalence and incidence. Also, it ascertained the characteristics of the injured subjects, the level of severity of the injuries and what definitions of injuries the available studies use.

METHODS

This systematic review followed the PRISMA recommendations and was registered in PROSPERO with the number CRD42021257010. The searches were performed in the PubMed, Cochrane and Web of Science, electronic databases using the Medical Subject Headings terms "Resistance training" or "Strength training" or "Crossfit" or "Weightlifting" or "Powerlifting" combined (AND) with "Injury" or "Injuries" or "Sprain" AND "Incidence" or "Prevalence" AND "Epidemiology" or "Epidemiological" in the title or abstract. The last search was performed on March 2023. To be included in the review, the studies had to be available as full text, be clinical trials focusing on epidemiological injuries of resistance training. There was no time limit for the selection of articles. To assess the quality of the studies, the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) was used.

RESULTS

The initial literature search resulted in 4982 studies. After reading the titles, abstracts and full text, 28 articles were selected for data extraction. Seventeen investigated the injuries in HIFT/CrossFit, three in powerlifting, three in strength training, three in weightlifting and one in strongman. In addition, one study examined the HIFT/CrossFit and weightlifting. The incidence of injuries presented in the studies ranged from 0.21/1000 h to 18.9/1000 h and the prevalence of injuries was 10% to 82%. In the quality assessment for STROBE, five studies were classified at level A, 21 at level B and two at level C.

CONCLUSION

This systematic review showed that traditional strength training is the safest RT method, and strongman is the least safe regarding injuries. Few studies have been rated highly according to STROBE. Furthermore, few studies have been published on some RT methods. These two factors make it difficult to generalize the results.

Narrative Review of Sex Differences in Muscle Strength, Endurance, Activation, Size, Fiber Type, and Strength Training Participation Rates, Preferences, Motivations, Injuries, and Neuromuscular Adaptations

ABSTRACT

Nuzzo, JL. Narrative review of sex differences in muscle strength, endurance, activation, size, fiber type, and strength training participation rates, preferences, motivations, injuries, and neuromuscular adaptations. J Strength Cond Res 37(2): 494-536, 2023-Biological sex and its relation with exercise participation and sports performance continue to be discussed. Here, the purpose was to inform such discussions by summarizing the literature on sex differences in numerous strength training-related variables and outcomes-muscle strength and endurance, muscle mass and size, muscle fiber type, muscle twitch forces, and voluntary activation; strength training participation rates, motivations, preferences, and practices; and injuries and changes in muscle size and strength with strength training. Male subjects become notably stronger than female subjects around age 15 years. In adults, sex differences in strength are more pronounced in upper-body than lower-body muscles and in concentric than eccentric contractions. Greater male than female strength is not because of higher voluntary activation but to greater muscle mass and type II fiber areas. Men participate in strength training more frequently than women. Men are motivated more by challenge, competition, social recognition, and a desire to increase muscle size and strength. Men also have greater preference for competitive, high-intensity, and upper-body exercise. Women are motivated more by improved attractiveness, muscle "toning," and body mass management. Women have greater preference for supervised and lower-body exercise. Intrasexual competition, mate selection, and the drive for muscularity are likely fundamental causes of exercise behaviors in men and women. Men and women increase muscle size and strength after weeks of strength training, but women experience greater relative strength improvements depending on age and muscle group. Men exhibit higher strength training injury rates. No sex difference exists in strength loss and muscle soreness after muscle-damaging exercise.

The Effect of Strength Training on Undetected Shoulder Pathology in Asymptomatic Athletes: An MRI Observational Study

BACKGROUND

Data on the effects of weight training on joint morphology are mostly restricted to muscle gain. However, in many circumstances, it is not stated if there are negative consequences for the joints and their surrounding components. This study was conducted to explore whether long-term excessive resistance training (RT) causes hidden pathological alterations in the shoulder.

METHODS

A total of eleven asymptomatic sportsmen (22 shoulders) underwent clinical and radiological examination of both shoulder joints. All participants had engaged in bodybuilding for at least four years, at least three times per week, and for at least four hours per week. All participants were examined clinically using the Constant Murley Score (CMS), Simple Shoulder Test (SST), UCLA Activity Test, and a specially designed questionnaire. All participants received a bilateral shoulder MRI. The MRI scans were checked for pathology using a checklist.

RESULTS

Maximum scores were observed for the SST and UCLA Activity Test. The CMS was 97.7 points on average (range, 87-100). RT had been conducted for a mean of 10.7 years (range, 4-20), for an average of 8.8 h a week (range, 4-12). MRI examinations revealed two supraspinatus tendinopathies (9.1%), one labral change (4.5%), three humeral tuberosity cysts (13.6%), fourteen acromioclavicular (AC) joint hypertrophies (63.6%), five AC joint osteophytes (22.7%), and ten signs of AC joint inflammation (45.5%).

CONCLUSIONS

The research results show that strength is associated with MRI-documented AC joint pathology. However, it appears that RT may not negatively affect other anatomical structures of the shoulder.

Effects of Blood Flow Restriction Combined with Low-Intensity Resistance Training on Lower-Limb Muscle Strength and Mass in Post-Middle-Aged Adults: A Systematic Review and Meta-Analysis

We studied the effect of blood flow restriction (BFR) combined with low-intensity resistance training (LIRT) on lower-limb muscle strength and mass in post-middle-aged adults. The PubMed, OVID, ProQuest, Cochrane Library, EMBASE, Web of Science, and Scopus databases were used to obtain randomized controlled trials, and the effects of BFR and LIRT (BFRt) on muscle strength and mass in adults were examined. The Cochrane risk of bias tool assessed bias in the included trials. The combined effects of BFR and LIRT (BFRt) were calculated by meta-analysis, the association between muscle strength/mass and interventions was determined by meta-regression, and beneficial variables of intervention were explored by subgroup analysis. A total of 11 articles were included in the meta-analysis. The combined effects showed that BFRt significantly improved lower extremity muscle strength but not muscle mass gain. Meta-regression analysis indicated that the effect of BFRt on changes in muscle strength was correlated with frequency of the intervention. Subgroup analysis revealed that BFRt achieved greater muscle strength gains than normal activity, LIRT, and similar muscle strength gains compared to high-intensity resistance training. The increased muscle strength after BFRt was noticed with a frequency of three times a week, but not with a frequency of two times a week, and the difference between these subgroups was statistically significant. Our findings indicate that BFRt can increase lower-limb muscle strength in post-middle-aged adults. Frequency of intervention is a key variable; particularly, a schedule of three times a week is effective in improving muscle strength.

Innovative Use of Biodex Balance System to Improve Dynamic Stabilization and Function of Upper Quarter in Recreational Weightlifters: A Randomized Controlled Trial

Background and Objectives: Following an injury, upper-body strength and proprioception training is typically suggested. To our understanding, no prior research has looked into the impact of balance training on upper-body strength and stability. So, this study investigated the effects of Biodex balance training on enhancing the dynamic stability, strength, and function of the upper quarter (UQ) in recreational weightlifters. Materials and Methods: Fifty male weightlifters were randomly assigned into two groups. The experimental group received an upper-extremity Biodex balance training program three times/week for eight weeks, while the control group underwent a regular weightlifting training routine. Pre- and post-test scores of the upper-quarter dynamic stability, strength, and function were measured for both groups using the shoulder active repositioning accuracy test, two-minute push-up test, and the upper-quarter Y-balance test (UQ-YBT) and one-arm hop test, respectively. Results: Post-test values were significantly greater for the normalized UQ-YBT test than pre-test values in both groups (p < 0.05). Post-test values of the experimental group were significantly greater than the control group (p < 0.05). Regarding the shoulder active repositioning accuracy test and the time of the one-arm hop test, post-test values were significantly lower than pre-test values for both groups (p < 0.05), and post-test values of the experimental group were significantly lower than those of the control group (p < 0.05). The post-test value of the two-minute push-up test of each group was significantly higher than the pre-test value (p < 0.05), without any significant difference between both groups (p > 0.05). Conclusions: Adding upper-body Biodex balance training to a regular weightlifting training routine was effective in enhancing the upper quarter′s dynamic stability and function.

Fitness Trainers' Educational Qualification and Experience and Its Association with Their Trainees' Musculoskeletal Pain: A Cross-Sectional Study

This is a cross-sectional study that examined the association between fitness trainers’ educational qualifications and experience, and the risk of their trainees’ musculoskeletal pain. The study included 1177 trainees (aged 15−60 years) from 74 fitness centers in Bangladesh. Data were collected by using the Nordic musculoskeletal questionnaire, including potential confounders such as demographic factors (e.g., age, occupation), and training-related factors (e.g., workout knowledge, overweight lifting). Multiple logistic regression was performed for a binary outcome (pain—yes or no), and a generalized linear model was fitted for the ordinal outcome (pain—sites of the body). The trainers’ lower experience (no or ≤1 year) was associated with higher odds of their trainees’ musculoskeletal pain (OR: 2.53, 95% CI: 1.18−5.44) compared to trainers with >5 years of experience; however, no association was found between the trainers’ education and the risk of their trainees’ musculoskeletal pain, after controlling for potential confounders. Similarly, the trainees trained by trainers with lower experience had more than two-time the risk of having pain in different sites (IRR: 2.04, 95% CI: 1.50−2.79). The trainers’ experience may play a pivotal role in the trainees’ musculoskeletal pain. Further study is warranted in this regard.

Evaluating peer-implemented video feedback to improve weight training form

This study evaluated the effectiveness of behavioral skills training (BST) to teach peer-trainers to implement video feedback (Study 1) and evaluated the effectiveness of peer-implemented video feedback to increase proper deadlifting form across 3 participants (Study 2). A nonconcurrent, multiple baseline design across participants was employed to evaluate BST and peer implemented video feedback. Results demonstrate that BST was effective for teaching peer-trainers to implement video feedback and video feedback led to improvement of deadlifting form across all participants.

Isokinetic Assessment of Shoulder Joint Strength Ratios in Male Recreational Weightlifters: A Cross-Sectional Study

Background

Isokinetic strength imbalance is a risk factor for movement dysfunctions and injuries related to shoulder complex. The effects of recreational weightlifting on developing the imbalances between the shoulder muscles are not yet known.

Objectives

To investigate the isokinetic concentric shoulder muscle strength values (peak torque normalized to body weight) in recreational weightlifters (RWL) and to compare the shoulder muscles agonist/antagonist ratios with nonweightlifters.

Methods

Thirty male RWL with mean age, weight, height, and body mass index (BMI) of 21.56 years, 84.25 kg, 175.34 cm, and 26.51 kg/m², respectively, matched with nonweightlifters served as a control group. The normalized concentric peak torque values of shoulder flexors, extensors, abductors, adductors, and internal and external rotators were measured at angular velocity 120°/sec by using Biodex isokinetic system. Moreover, the agonist/antagonist strength ratio for all muscle groups were calculated.

Results

The normalized peak torques of RWL group were significantly greater than the control group (p < 0.05). The abductor/adductor and external rotator/internal rotator ratios of the RWL were significantly lower than the control group (p = 0.008 and 0.009, respectively). Conversely, there was no significant difference between both groups in relation to the flexor/extensor ratio (p = 0.259).

Conclusion

These results suggested that the recreational weightlifting exercises place trainees at risk of muscle imbalances. Therefore, the restoration of a normal concentric abductor/adductor and external rotator/internal rotator strength ratios may decrease the risk of possible shoulder injury.

Health challenges and acute sports injuries restrict weightlifting training of older athletes

Objectives

To quantify acute injuries sustained during weightlifting that result in training restrictions and identify potential risk factors or preventative factors in Master athletes and to evaluate potentially complex interactions of age, sex, health-related and training-related predictors of injuries with machine learning (ML) algorithms.

Methods

A total of 976 Masters weightlifters from Australia, Canada, Europe and the USA, ages 35–88 (51.1% women), completed an online survey that included questions on weightlifting injuries, chronic diseases, sport history and training practices. Ensembles of ML algorithms were used to identify factors associated with acute weightlifting injuries and performance of the prediction models was evaluated. In addition, a subgroup of variables selected by six experts were entered into a logistic regression model to estimate the likelihood of an injury.

Results

The accuracy of ML models predicting injuries ranged from 0.727 to 0.876 for back, hips, knees and wrists, but were less accurate (0.644) for shoulder injuries. Male Master athletes had a higher prevalence of weightlifting injuries than female Master athletes, ranging from 12% to 42%. Chronic inflammation or osteoarthritis were common among both men and women. This was associated with an increase in acute injuries.

Conclusions

Training-specific variables, such as choices of training programmes or nutrition programmes, may aid in preventing acute injuries. ML models can identify potential risk factors or preventative measures for sport injuries.

The aging athlete

Aging athletes, those 60 years and older, are a growing population of mature, active individuals who value sports and exercise participation throughout their lifespan. Although recommendations for younger and masters athletes have been extrapolated to this population, there remains a paucity of specific guidelines, treatment algorithms, and considerations for aging athletes. The benefits of living an active lifestyle must be weighed against the risks for unique cardiovascular, metabolic, and musculoskeletal injuries requiring diagnostic and therapeutic interventions. In this article, we review the unique cardiovascular and muscular physiology of aging athletes and how it influences the risk of specific medical conditions. We also discuss general prevention and treatment strategies. Finally, we identify areas of future research priorities and emerging treatments.

Effects of 40% of Maximum Oxygen Uptake Intensity Cycling Combined with Blood Flow Restriction Training on Body Composition and Serum Biomarkers of Chinese College Students with Obesity

Blood flow restriction training (BFRT) is a new method for promoting muscle growth and improving muscle function, even with relatively low-intensity exercise. BFRT on patients with obesity has not been extensively studied. This study aimed to analyze the effects of cycling at 40% of maximum oxygen uptake (VO₂max) combined with BFRT on body composition and serum biomarkers among college students with obesity. This pilot study included thirty-seven male college students with obesity aged 18-22 years (experimental group (EG): n = 18; control group (CG): n = 19). The EG conducted 40% VO₂max cycling combined with BFRT activities and the CG conducted 40% VO₂max cycling without BFRT two times per week for 12 weeks. Our results showed that in EG, there were significant differences in weight, thigh skinfold thickness (TS), waist circumference, abdominal skinfold thickness, fat mass, body fat percentage, body mass index and glucose (GLU), total cholesterol (TC), triglyceride, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels before and after the experiment (p < 0.05, p < 0.01, and p < 0.001). After the experiment, TS, GLU, TC, HDL-C, and LDL-C in EG were significantly different than those of the CG (p < 0.05, p < 0.01, and p < 0.001). Together, our results demonstrate that cycling at 40% VO₂max combined with BFRT may improve body composition and blood lipid profile of male college students with obesity. Our findings have important implications for those who cannot perform moderate- and high-intensity exercises.

Effects of resistance training in healthy older people with sarcopenia: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

We conducted a meta-analysis to analyze the effects of resistance training on measures of body composition, muscle strength, and muscle performance in older people with sarcopenia.

METHODS

All randomized controlled trials on the effects of resistance training on outcome variables in older people with sarcopenia were searched on Pubmed, Embase, Cochrane Library, the China National Knowledge Infrastructure (CNKI), and Wanfang. Data from January 2010 to October 2020 were reviewed. Two researchers extracted data and evaluated the quality of the studies that met the inclusion criteria independently. Meta-analysis for pre-post changes were calculated as standardized mean difference (SMD) with 95% confidence intervals (CI).

RESULTS

Fourteen studies meeting inclusion criteria included 561 healthy older adults (age 65.8 to 82.8) with sarcopenia. Compared with the control group, resistance training had positive effects on body fat mass (SMD = -0.53, 95% CI - 0.81 to - 0.25, p = 0.0002, I² = 0%), handgrip strength (SMD = 0.81, 95%CI 0.35 to 1.27, p = 0.0005, I² = 81%), knee extension strength (SMD = 1.26, 95% CI 0.72 to 1.80, p < 0.0001, I² = 67%), gait speed (SMD = 1.28, 95%CI 0.36 to 2.19, p = 0.006, I² = 89%), and the timed up and go test (SMD = -0.93, 95% CI - 1.30 to - 0.56, p < 0.0001, I² = 23%). Resistance training had no effects on appendicular skeletal muscle mass (SMD = 0.25, 95% CI - 0.27 to 0.78, p = 0.35, I² = 68%), skeletal muscle mass (SMD = 0.27, 95% CI - 0.02 to 0.56, p = 0.07, I² = 0%) and leg lean mass (SMD = 0.12, 95% CI - 0.25 to 0.50, p = 0.52, I² = 0%). Old people with sarcopenia of different ages, genders or diagnostic criteria and weights have different gains in muscle mass, handgrip strength, knee extension strength and muscle performance after different intervention duration, frequencies, mode and intensity resistance training.

CONCLUSION

Resistance training is an effective treatment to improve body fat mass, muscle strength, and muscle performance in healthy older people with sarcopenia.

Efficacy of low-load resistance training combined with blood flow restriction vs. high-load resistance training on sarcopenia among community-dwelling older Chinese people: study protocol for a 3-arm randomized controlled trial

BACKGROUND

Sarcopenia is accompanied by a decline in muscle mass, muscle strength, and muscle function. Resistance training is the most potential training method for the prevention and treatment of sarcopenia. However, the conventional high-load resistance training (CRT) recommended by the American College of Sports Medicine is a challenge for older people with sarcopenia. As a novel training method, low-load resistance training combined with blood flow restriction (LRT-BFR) may elicit similar muscle mass and muscle strength gains as CRT but with less effort. The objectives of this study are to assess and compare the efficacy and safety of 12-week LRT-BFR and CRT on muscle strength, muscle performance, body composition, pulmonary function, blood biomarkers, CVD risk factors, and quality of life in community-dwelling older Chinese people with sarcopenia.

METHOD

This is a 12-week, assessor-blinded, 3-arm randomized controlled trial with a non-exercise control group. Community-dwelling people over 65 years will be screened for sarcopenia according to the diagnostic criteria of the Asian Working Group for Sarcopenia (AWGS). Fifty-one subjects will be randomized into a LRT-BFR group (n = 17), a CRT group (n = 17), and a no-strength training control group (n = 17). The primary outcome is lower limb muscle strength. The secondary outcomes are body composition, upper limb muscle strength, pulmonary function, blood biomarkers, CVD risk factors, and quality of life. Post-intervention follow-up will be performed for 12 weeks. These indicators will be assessed at baseline (0 week), after the 12-week intervention (12 weeks), and at follow-up (24 weeks). The adverse events will also be reported. Data will be analyzed for all participants in an intent-to-treat plan.

DISCUSSION

This study is the first RCT that will systematically measure and compare the efficacy and safety of LRT-BFR and CRT in older people with sarcopenia on muscle strength, body composition, pulmonary function, blood biomarkers (inflammatory biomarkers, hormone, and growth factors), CVD risk factors, and quality of life. This study can provide an efficient and safe method to prevent the progression of sarcopenia in older people.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100042803 . Registered on 28 January 2021.

No Time to Lift? Designing Time-Efficient Training Programs for Strength and Hypertrophy: A Narrative Review

Abstract

Lack of time is among the more commonly reported barriers for abstention from exercise programs. The aim of this review was to determine how strength training can be most effectively carried out in a time-efficient manner by critically evaluating research on acute training variables, advanced training techniques, and the need for warm-up and stretching. When programming strength training for optimum time-efficiency we recommend prioritizing bilateral, multi-joint exercises that include full dynamic movements (i.e. both eccentric and concentric muscle actions), and to perform a minimum of one leg pressing exercise (e.g. squats), one upper-body pulling exercise (e.g. pull-up) and one upper-body pushing exercise (e.g. bench press). Exercises can be performed with machines and/or free weights based on training goals, availability, and personal preferences. Weekly training volume is more important than training frequency and we recommend performing a minimum of 4 weekly sets per muscle group using a 6–15 RM loading range (15–40 repetitions can be used if training is performed to volitional failure). Advanced training techniques, such as supersets, drop sets and rest-pause training roughly halves training time compared to traditional training, while maintaining training volume. However, these methods are probably better at inducing hypertrophy than muscular strength, and more research is needed on longitudinal training effects. Finally, we advise restricting the warm-up to exercise-specific warm-ups, and only prioritize stretching if the goal of training is to increase flexibility. This review shows how acute training variables can be manipulated, and how specific training techniques can be used to optimize the training response: time ratio in regard to improvements in strength and hypertrophy.

Graphic Abstract

Concurrent endurance and resistance training enhances muscular adaptations in individuals with metabolic syndrome

The purpose of the study was to determine if concurrent training (endurance and resistance in a single session) elicits leg muscular adaptations beyond the ones obtained by endurance training alone in sedentary individuals with metabolic syndrome (MetS). Sixty-six MetS individuals (37% women, age 56 ± 7 years, BMI 32 ± 5 kg m^-2 and 3.8 ± 0.8 MetS factors) were randomized to undergo one of the following 16-week isocaloric exercise programs: (i) 4 + 1 bouts of 4 min at 90% of HR_MAX of intense aerobic cycling (IAC + IAC group; n = 33), (ii) 4 IAC bouts followed by 3 sets of 12 repetitions of 3 lower-limb free-weight exercises (IAC + RT group; n = 33). We measured the effects of training on maximal cycling power, leg press maximum strength (1RM), countermovement jump height (CMJ), and mean propulsive velocity (MPV) at workloads ranging from 10% to 100% of baseline 1RM leg press. After intervention, MetS components (Z-score) improved similarly in both groups (p = 0.002). Likewise, maximal cycling power during a ramp test improved similarly in both groups (time effect p < 0.001). However, leg press 1RM improved more in IAC + RT than in IAC + IAC (47 ± 5 vs 13 ± 5 kg, respectively, interaction p < 0.001). CMJ only improved with IAC + RT (0.8 ± 0.2 cm, p = 0.001). Leg press MPV at heavy loads (ie, 80%-100% 1RM) improved more with concurrent training (0.12 ± 0.01 vs 0.06 ± 0.02 m s^-1 , interaction p = 0.013). In conclusion, in unconditioned MetS individuals, intense aerobic cycling alone improves leg muscle performance. However, substituting 20% of intense aerobic cycling by resistance training further improves 1RM leg press, MPV at high loads, and jumping ability while providing similar improvement in MetS components.

A Retrospective Observational Study of Presentations to an Australian Emergency Department for Injuries Sustained in Exercise Pursuits Over 14 Years

Background: Concurrent with the increase in the number of local gyms and the number of people engaged in fitness pursuits, exercise-related emergency department (ED) presentations have also increased. Identifying these injuries and the associated activities and equipment will help inform prevention strategies and potentially reduce the burden on the healthcare system. Methods: We reviewed the presentations to an Australian tertiary hospital ED resulting from running/jogging and gym-based exercise from 2005 to 2018. Results: From more than 750,000 ED visits, we identified 1,402 exercise-related presentations. Approximately two-thirds of the patients were males. Nontrauma such as chest pain and shortness of breath accounted for 11% of the presentations. Running and jogging contributed 47% of the total presentations, followed by combat activities (boxing and martial arts) with 31% of the total presentations. In the latter group, most injuries were to the head (25%) and upper limbs (39%). Injuries associated with weights/resistance activities (n=94) and falls from treadmills (n=49) accounted for 55% of the 260 injuries from use of noncombat-sports-related gym equipment. Twenty-three percent of all presentations arrived by ambulance, and overall, 9% of presentations required hospital admission. Over a 14-year period, the annual presentations rate rose from <1 to >2.5 per 1,000. Conclusion: Although the annual rate of presentations to the ED from exercise has more than doubled, exercise-related presentations still constitute only a small proportion of total presentations. Nevertheless, any reduction would be advantageous to an already overstretched health system. Risk awareness and effective education about equipment and its use at point of sale and in gyms could potentially prevent many presentations.

Safety and Effectiveness of Progressive Moderate-to-Vigorous Intensity Elastic Resistance Training on Physical Function and Pain in People With Hemophilia

OBJECTIVE

Strength training is recommended for people with hemophilia; however, published data are anecdotal and have methodological limitations. The purpose of this study was to evaluate the safety and effectiveness of progressive moderate-to-vigorous intensity elastic resistance training on physical function and pain in this patient population.

METHODS

A randomized controlled trial was conducted in a university laboratory setting where 20 patients (17 with severe, 1 with moderate, and 2 with mild hemophilia) aged 21 to 53 years received evaluations at baseline and 8-week follow-up. Participants were allocated to intervention (progressive strength training) or control (usual daily activities) groups. The intervention group trained 2 days per week during 8 weeks with elastic resistance. Intensity during the first 2 weeks was a 20-repetition maximum and increased progressively toward 15, 12, and finally 10 repetition maximum. The primary outcome was muscle strength. Secondary outcomes were the Timed "Up and Go" Test score, sit-to-stand, range of motion, Haemophilia Joint Health Score, kinesiophobia score, global impression of pain change, general self-rated health status, and desire to exercise.

RESULTS

The intervention group showed greater strength improvements than the control group in almost all of the joints, with moderate to high effect sizes. The intervention group also showed better Timed "Up and Go" and sit-to-stand scores than the control group (moderate effect size), greater range of motion at the knee flexion with the right leg (trivial effect size), and better Haemophilia Joint Health Score at the left knee (small effect size). The intervention group showed greater overall pain reduction, self-rated overall status, and desire to exercise than the control group.

CONCLUSIONS

Progressive strength training with elastic resistance performed twice a week during 8 weeks is safe and effective in people with hemophilia to improve muscle strength and functional capacity, reduce general pain, and improve self-rated health status and desire to exercise.

IMPACT

This study provides evidence for the use of a specific strength training regimen for people with hemophilia.

LAY SUMMARY

People with hemophilia of differing levels of severity, with adequate coverage with clotting factor, can safely engage in progressive strength training and can improve their functioning.

Injury Risk Factors Associated With Weight Training

Grier, T, Brooks, RD, Solomon, Z, and Jones, BH. Injury risk factors associated with weight training. J Strength Cond Res XX(X): 000-000, 2020-The purpose of this evaluation was to identify injury risk factors associated with weight training (WT). Subjects were 4,785 men and 542 women in a U.S. Army Division. Personal characteristics, unit training, personal training, fitness, and 12-month injury history were obtained by an electronic survey. Risk factors for WT injuries were explored using backward stepping multivariable logistic regression. Risk ratios, odds ratios (ORs), and 95% confidence intervals (95% CIs) were calculated for each risk factor. Over a one-year period, 4.5% of men and 0.6% of women experienced a WT injury. Weight-training injury incidence was 0.31 and 0.05 per 1,000 hours of WT for men and women, respectively. Overall, men were 7.4 times more likely to experience a WT injury compared with women. For men who participated in WT, independent risk factors for a WT injury included older age (OR [23-27/≤ 22 years] = 1.99, 95% CI 1.22-3.27; OR [>28/≤ 22 years] = 2.48, 95% CI 1.52-4.03) and higher amounts of personal WT per week (OR [60-165/≥ 166 minutes] = 0.58, 95% CI 0.39-0.88; and OR [15-59/≥ 166 minutes] = 0.40, 95% CI 0.24-0.66). A linear trend was revealed indicating an increasing risk of a WT injury with greater amounts of time spent WT per week (p < 0.01). Performing moderate amounts of WT may reduce the risk of experiencing a WT injury. However, because muscle strength is an important component of fitness for Soldiers, specialized WT programs that improve strength while minimizing injury risks are needed.

Magnetic Resonance Imaging of Pectoralis Major Injuries in an Active Duty Military Cohort: Mechanism Affects Tear Location

Background:

Pectoralis major (PM) tendon tears are common injuries in athletic patient populations, where operative repair is largely recommended for maximum functional recovery. The repair varies in difficulty and technique based on the location of the tear within the muscle-tendon unit. Magnetic resonance imagining (MRI) has been reported to be sensitive and specific for identifying the tear location, but the effect of injury mechanism on tear pattern has not been previously investigated.

Purpose:

To examine PM tears in a military patient population and assess the effect of injury mechanism (weightlifting vs high-energy trauma) on the tear pattern and accuracy of MRI interpretation.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Active duty military servicemembers undergoing operative repair of PM tendon tears with corresponding preoperative MRIs from 2 medical centers were identified. Two musculoskeletal fellowship–trained radiologists reviewed imaging studies, reporting the location of the tear within the muscle-tendon unit and the severity of the tear (sternal head vs clavicular head vs both). Radiographic findings were compared against intraoperative findings. Mechanism of injury and timing from injury to imaging and surgery were assessed to determine whether they affected the accuracy of MRI interpretations.

Results:

A total of 72 patients were included (mean ± SD age, 33.7 ± 7.0 years; 100% male). Mechanisms of injury consisted of 46 weightlifting injuries and 26 high-energy injuries. Interrater reliability was poor for tear location (kappa, 0.162; P = .003) but substantial for extent of tear (kappa, 0.637; P < .0001). MRI had a 51.3% sensitivity and 63.6% specificity for identifying complete tears. MRI had a sensitivity of 73.9% and specificity of 72.2% for avulsion injuries and sensitivity of 75% and specificity of 79.3% for musculotendinous injuries. Mechanism of injury had no effect on extent of the tear but did affect the location of the tear, with a higher rate of avulsion injuries in the high-energy mechanism cohort (81% vs 40%; P = .02).

Conclusion:

The mechanism of injury was found to significantly affect the location of tendon tears. A higher rate of avulsion injuries was found in high-energy injuries than weightlifting injuries. MRI appeared to be less sensitive and specific than previous reports for traumatic PM tendon injuries.

Resistance Training for Children and Adolescents

Resistance training is becoming more important as an integral part of comprehensive sport training regimens, school physical education classes, and after-school fitness programs. The increasing number of youth who are involved in sport activities, coupled with the health problems of inactivity and being overweight, have resulted in increased interest in resistance training. Secular declines in measures of muscular fitness in modern-day youth highlight the need for participation in youth resistance training for nonathletes as well as athletes. Parents often ask pediatricians to offer advice regarding the safety, benefits, and implementation of an effective resistance-training program. This report is a revision of the 2008 American Academy of Pediatrics policy statement and reviews current information and research on the benefits and risks of resistance training for children and adolescents.

Case report of a surgical neck humerus fracture due to strength training

The incidence of the surgical neck fractures of humerus is increasing, especially among younger age groups as they place higher demands on their shoulder joints. Resistance training and heavy weight lifting have been implicated in a number of orthopedic upper extremity injuries. Acute sprains or strains are the most common type of reported injuries. Other reported weightlifting injuries includes pectoralis tendon ruptures, distal bicep injury, and shoulder capsulolabral complex injuries. To our best knowledge, there are no reported cases in the literature describing surgical neck humeral fracture in a young adult due to heavy weight strength training without any underlying medical predisposing condition. This case report describes a surgical neck proximal humeral undisplaced fracture in a 44 year old male which was treated conservatively with an uneventful recovery.

Upper-Body Exercises With External Resistance Are Well Tolerated and Enhance Muscle Activity in People With Hemophilia

BACKGROUND

Conventional nonresisted therapeutic exercises for people with hemophilia involve a careful, low-intensity approach to avoid injuries. Externally resisted exercise is highly efficient for increasing muscle strength in healthy adults but its feasibility for people with hemophilia remains unknown.

OBJECTIVE

The purpose of this study was to evaluate muscle activity during upper-body rehabilitation exercises with 2 types of external resistance and without external resistance (conventional) and to examine tolerability, kinesiophobia, and possible adverse effects derived from the session.

DESIGN

This was a cross-sectional study.

METHODS

Twelve people with hemophilia A/B (11 with severe hemophilia undergoing prophylactic treatment, 1 with mild hemophilia) participated. During the experimental session, participants completed the Tampa Scale of Kinesiophobia and performed 2 exercises-elbow flexion and shoulder abduction-with 3 conditions for each exercise: elastic resistance (externally resisted), free weights (externally resisted), and conventional nonresisted. Surface electromyography signals were recorded for the biceps brachii, triceps brachii, upper trapezius, and middle deltoid muscles. After the session, exercise tolerability and kinesiophobia were assessed. Adverse effects were evaluated 24 and 48 hours after the session.

RESULTS

Externally resisted exercises provided greater muscle activity than conventional nonresisted therapeutic exercises. The exercises were generally well tolerated and there was no change in kinesiophobia following the session. No adverse effects were observed in the following days.

LIMITATIONS

Small sample size was the main limitation.

CONCLUSIONS

In people with severe hemophilia undergoing prophylactic treatment, elbow flexion and shoulder abduction exercises with external resistance at moderate intensities are feasible and provide greater muscle activity than nonresisted conventional exercises.

Effect of Ankle Mobility and Segment Ratios on Trunk Lean in the Barbell Back Squat

Fuglsang, EI, Telling, AS, and Sørensen, H. Effect of ankle mobility and segment ratios on trunk lean in the barbell back squat. J Strength Cond Res 31(11): 3024-3033, 2017-The barbell back squat is a popular exercise used for both performance enhancing and rehabilitation purposes. However, injuries are common, and people with a history of lower back pain are especially vulnerable. Past studies have shown that higher trunk angles (less forward lean) generate less stress on the lower back; thus, it seems appropriate to investigate the factors presumed to influence the trunk angle. Therefore, the aim of this study was to investigate how ankle mobility and the segment ratios between the thoracic spine, thighs, and shanks influence the trunk angle in the back squat. While recorded with motion capture, 11 male subjects performed 3 repetitions at approximately 75% of 1 repetition maximum in the squat to a parallel position (thighs horizontal) or lower. Furthermore, subjects performed a weight bearing lunge test to determine maximal range of motion (ROM) of the ankle joint. Segment angles of the shank, thigh, and trunk segments as well as ankle joint angles were calculated by 2-dimensional kinematic analysis. Simple linear and multiple regressions were used to test the correlation between the lower extremity angles, segment ratios, and the trunk angle. On average, subjects had an 11.4 ± 4.4° deficit in dorsiflexion ROM between maximal ROM and ROM in the parallel squat (PS) which was independent of maximal ROM. Ankle mobility showed to significantly negatively correlate with trunk angle, thereby showing that a subject with greater ankle ROM had a more upright torso in the PS position. This study was unable to find a significant correlation between the segment ratios and trunk angle. Furthermore, when combined, no significant relationship between ankle mobility, segment length ratios, and trunk angle were found, although it was noticed that this more complex model showed the greatest R value.

Upper extremity weightlifting injuries: Diagnosis and management

Common upper extremity injuries in resistance training athletes include muscle strains, ligament sprains, pectoralis major tendon ruptures, distal biceps tendon ruptures, and chronic shoulder pain and capsulolabral injuries. While each injury is unique in its specific anatomic location and mechanism, each is preventable with proper exercise technique, safety and maintenance of muscle balance. Conservative treatment is the therapeutic modality of choice and these injuries generally resolve with workout modification, appropriate recovery, anti-inflammatory medication, and physical therapy. If conservative treatment fails, surgical intervention is often successful and can return the weightlifter to a level of performance near their pre-injury level.

A minimal dose approach to resistance training for the older adult; the prophylactic for aging

A plethora of research has supported the numerous health benefits of resistance training as we age, including positive relationships between muscular strength, muscle mass and reduced all-cause mortality. As such, resistance training has been referred to as medicine. However, participation and adherence remains low, with time constraints and perceived difficulty often cited as barriers to resistance training. With this in mind, we aimed to summarise the benefits which might be obtained as a product of a minimal dose approach. In this sense, participation in resistance training might serve as a prophylactic to delay or prevent the onset of biological aging. A short review of studies reporting considerable health benefits resulting from low volume resistance training participation is presented, specifically considering the training time, frequency, intensity of effort, and exercises performed. Research supports the considerable physiological and psychological health benefits from resistance training and suggests that these can be obtained using a minimal dose approach (e.g. ≤60min, 2d-wk^-1), using uncomplicated equipment/methods (e.g. weight stack machines). Our hope is that discussion of these specific recommendations, and provision of an example minimal dose workout, will promote resistance training participation by persons who might otherwise have not engaged. We also encourage medical professionals to use this information to prescribe resistance exercise like a drug whilst having an awareness of the health benefits and uncomplicated methods.

Diagnosis of Paget-Schroetter Syndrome/Primary Effort Thrombosis in a Recreational Weight Lifter

BACKGROUND AND PURPOSE

Paget-Schroetter syndrome (PSS) is a rare condition of vein thrombosis that can be manifested in athletes and laborers who overuse their upper extremities. If diagnosed early, PSS can be managed and the symptoms can be fully reversed. Venous duplex ultrasound (US), the modality most commonly used to diagnose deep vein thrombosis (DVT), has high sensitivity and specificity for detecting DVT. This case report describes the differential diagnosis and management of PSS in a weight lifter.

CASE DESCRIPTION

The patient was a 44-year-old man who had left upper extremity (UE) swelling and discoloration after performing an incline chest press 2 months earlier. He was referred to a physical therapist for the treatment of venous thoracic outlet syndrome because US imaging results were negative for DVT. The patient's signs and symptoms did not improve after 4 physical therapist treatment sessions.

OUTCOMES

Repeat US revealed multiple thrombi in the patient's UE. He underwent immediate thrombolysis and subsequent first rib removal and scalenectomy. Five months after the surgical intervention, the patient had returned to work as a truck driver without limitation of UE use, although he had not yet returned to weight lifting.

DISCUSSION

Despite the facts that the patient was seen by several health care providers and that multiple US images were obtained, the patient's UE DVT was not detected. It is important for a clinician to consider venous pathology in the shoulder even if the results of diagnostic US imaging performed in the presence of UE swelling and pain have been negative. Timely diagnosis and management of PSS are necessary for optimal recovery.

Transcriptional profiling of rat skeletal muscle hypertrophy under restriction of blood flow

Blood flow restriction (BFR) under low-intensity resistance training (LIRT) can produce similar effects upon muscles to that of high-intensity resistance training (HIRT) while overcoming many of the restrictions to HIRT that occurs in a clinical setting. However, the potential molecular mechanisms of BFR induced muscle hypertrophy remain largely unknown. Here, using a BFR rat model, we aim to better elucidate the mechanisms regulating muscle hypertrophy as induced by BFR and reveal possible clinical therapeutic targets for atrophy cases. We performed genome wide screening with microarray analysis to identify unique differentially expressed genes during rat muscle hypertrophy. We then successfully separated the differentially expressed genes from BRF treated soleus samples by comparing the Affymetrix rat Genome U34 2.0 array with the control. Using qRT-PCR and immunohistochemistry (IHC) we also analyzed other related differentially expressed genes. Results suggested that muscle hypertrophy induced by BFR is essentially regulated by the rate of protein turnover. Specifically, PI3K/AKT and MAPK pathways act as positive regulators in controlling protein synthesis where ubiquitin-proteasome acts as a negative regulator. This represents the first general genome wide level investigation of the gene expression profile in the rat soleus after BFR treatment. This may aid our understanding of the molecular mechanisms regulating and controlling muscle hypertrophy and provide support to the BFR strategies aiming to prevent muscle atrophy in a clinical setting.

Distal clavicular osteolysis in adults: association with bench pressing intensity

OBJECTIVES

To investigate the association between distal clavicular osteolysis (DCO) and bench pressing intensity.

METHODS

From a retrospective review of MRI shoulder reports of individuals between 20 and 40 years of age, 262 male patients with DCO and 227 age-matched male patients without DCO were selected. All patients had completed a bench pressing questionnaire. The patients' bench pressing frequency (times per week), duration (years of bench pressing), bench pressing weight (maximum bench pressing weight with one repetition = 1RM) and the ratio of bench pressing weight to body weight were compared between both groups using Chi-square and Mann-Whitney tests.

RESULTS

The results showed that 56 % (146/262) of patients with DCO were high-intensity bench pressers (1RM more than 1.5 times the body weight) compared to 6 % (14/227) in patients without DCO. High-intensity bench pressing was a risk factor for DCO (OR = 19; 95 %CI = 11-35; p < 0.001). Low-intensity bench pressing (1RM less than 1.5 times the body weight) was not a risk factor for DCO (OR = 0.6; 95 % CI = 0.4-0.8). High frequency (>1×/week) and duration (>5 years) of bench pressing were risk factors. In bench pressers who suffered from DCO, the mean 1RM was 283 lbs (±SD 57) compared to 209 lbs (±SD 60) in bench pressers not affected by DCO (p < 0.001, Mann-Whitney).

CONCLUSIONS

High-intensity, but not low-intensity bench pressing is a risk factor for DCO.

Personal Trainer Demographics, Current Practice Trends and Common Trainee Injuries

Increasing emphasis on maintaining a healthy lifestyle has led many individuals to seek advice on exercise from personal trainers. There are few studies to date that evaluate personal trainer education, practice trends, and injuries they have seen while training clients. A survey was distributed to personal trainers using Survey Monkey® (Palo Alto, CA, USA) with 605 personal trainers accessing the survey. An exercise related bachelor’s degree was held by 64.2% of survey participants and a certification in personal training by 89.0%. The most common personal trainer certifications were from American College of Sports Medicine (59.2%) and National Strength and Conditioning Association (28.9%). Only 2.9% of all personal trainers surveyed had no exercise-related bachelor’s degree and no personal trainer certification. The most common injuries seen by personal trainers during sessions were lumbar muscle strain (10.7%), rotator cuff tear/tendonitis (8.9%), shin splints (8.1%), ankle sprain (7.5%), and cervical muscle strain (7.4%). There is variability in the practices between different personal trainers when analyzing differences in collegiate education, personal trainer certifications, and strength and conditioning certifications. The clinical implication of the differences in practices is unknown as to the impact on injuries or exercise prescription effectiveness.

Acute Pectoralis Major Rupture Captured on Video

Pectoralis major (PM) ruptures are uncommon injuries, although they are becoming more frequent. We report a case of a PM rupture in a young male who presented with axillar pain and absence of the anterior axillary fold after he perceived a snap while lifting 200 kg in the bench press. Diagnosis of PM rupture was suspected clinically and confirmed with imaging studies. The patient was treated surgically, reinserting the tendon to the humerus with suture anchors. One-year follow-up showed excellent results. The patient was recording his training on video, so we can observe in detail the most common mechanism of injury of PM rupture.

Shoulder Joint and Muscle Characteristics Among Weight-Training Participants With and Without Impingement Syndrome

Kolber, MJ, Hanney, WJ, Cheatham, SW, Salamh, PA, Masaracchio, M, and Liu, X. Shoulder joint and muscle characteristics among weight-training participants with and without impingement syndrome. J Strength Cond Res 31(4): 1024-1032, 2017-Subacromial impingement syndrome (SIS) has been reported as an etiological source of shoulder pain among weight-training (WT) participants; however, a paucity of evidence exists to describe intrinsic risk factors. The purpose of this study was to investigate specific risk-related joint and muscle adaptations among WT participants identified as having SIS based on a previously validated clinical testing cluster. Fifty-five men (mean age 27.3 years) who participated in recreational WT a minimum of 2 d·wk were recruited, including 24 individuals with SIS and 31 without SIS serving as controls. Active range of motion (AROM), bodyweight-adjusted strength values, and strength ratios were compared between groups. Significant differences were present as WT participants with SIS had decreased internal and external rotation AROM (p ≤ 0.016) and decreased bodyweight-adjusted strength values of the external rotator and lower trapezius musculature (p ≤ 0.02) when compared with WT participants without SIS. Select strength ratios were greater in the SIS group (p ≤ 0.004) implying agonist to antagonist muscle imbalances. The impaired joint and muscle characteristics identified among WT participants with SIS are not without consequence, as they are associated with shoulder disorders in both general and athletic populations. Practical applications for these findings may reside in exercise prescription that addresses internal rotation mobility, mitigates training bias, and favors muscles responsible for stabilization, such as the external rotators and lower trapezius. Strength and conditioning professionals should consider risk-related adaptations associated with WT when prescribing upper-extremity exercises.

Epidemiology of Exercise- and Sports-Related Injuries in a Population of Young, Physically Active Adults: A Survey of Military Servicemembers

BACKGROUND

Numerous studies document the health benefits of a physically active lifestyle, but relatively few document the hazards of physical activity. Because of the requirement for physical fitness to complete their mission, the United States military services have a vested interest in understanding the benefits and risks of physical activity including exercise and sports. One of these risks is injury. Rates and proportion of injuries caused by exercise- and sports-related (ESR) activities have not been reported previously across the services.

PURPOSE

The purposes of this population survey were to (1) document the rates and proportion of all injuries caused by ESR activities among military personnel, (2) compare rates across the military services, and (3) describe the causes and types of ESR injuries as well as associated days of limited activity.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

The Defense Manpower Data Center administered the web-based 2008 Status of Forces Survey of Active Duty Service Members to a random sample of active-duty personnel. In all, 10,692 servicemembers completed the survey, which included questions about injuries from any cause and from exercise and sports during the previous year. Responses were weighted to produce population estimates for injury rates (any injury and ESR injury). Percentage distributions were used to describe activities, injury types, days of limited activity, and contributing factors for ESR injuries.

RESULTS

There were 49% of servicemembers who sustained an injury from any cause in the previous year; 25% had an ESR injury. Thus, 52% of all injuries were ESR injuries. ESR injury rates ranged from 20% for the Navy to 33% for the Marine Corps. Running accounted for 45% of ESR injuries. Forty percent of ESR injuries were sprains and strains. As an indicator of injury severity, 35% of ESR injuries required more than 2 weeks of limited activity.

CONCLUSION

This study quantified the overall incidence of injuries and the large proportion that are caused by exercise and sports among military personnel, a population of healthy, physically active adults. Prevention strategies should focus on running, weight training, basketball, and football. Recommendations include adherence to evidence-based practices to reduce the occurrence of ESR injuries.

The causes of injuries sustained at fitness facilities presenting to Victorian emergency departments - identifying the main culprits

Background

Fitness facilities provide an avenue to engage in physical activity, which is widely encouraged to improve health. However, there is risk of injury. This study aimed to identify the specific causes of injuries sustained at fitness facilities and the activity being participated in, to aid in the development of injury prevention strategies.

Methods

Analysis of routinely collected emergency department case-series data were obtained from July 1999 to June 2013. Fitness activity-related injury cases were identified from narratives of injury events, with narrative information recoded into cause of injury and activity at time of injury categories. Recoded data were then analysed.

Results

Overall, 2,873 cases were identified that specified the exact cause of injury associated with injuries that occurred at fitness facilities. Injuries due to overexertion were most common overall (36.2% of all cases), as well as the main cause of injuries related to general free weight activities (52.6% of this activity) and group exercise classes (35.9%). Crush injuries due to falling weights were common for all free weight activities. Falls and awkward landings were common causes of injuries during group exercise classes (28.5% and 25.8%, respectively). Trips and falls were common throughout facilities, as well as from cardiovascular equipment more specifically.

Conclusions

Detailed information on the causes of injuries allows the development of injury prevention strategies for fitness facilities and fitness activities. Facilities should implement risk management strategies to reduce the risk of injuries in their clientele, based on the identified major causes of injury in this study.

Epidemiology of hospital-treated injuries sustained by fitness participants

PURPOSE

The purpose of this study was to provide an epidemiological profile of injuries sustained by participants in fitness activities in Victoria, Australia, based on hospital admissions and emergency department (ED) presentations and to identify the most common types, causes, and sites of these injuries.

METHOD

Hospital-treated fitness activity-related injury cases were identified from International Classification of Disease activity codes (for admissions) and from text narratives of injury events (for ED presentations) from 2003 to 2010, inclusive. Cases were categorized as being associated with aerobics/group exercise (n = 252), resistance/weight training (n = 830) or "other equipment" (motorized and general gym equipment; n = 1,156). Participation information was taken from the Exercise, Recreation and Sport Survey.

RESULTS

Overall, 2,238 cases were identified and 11.6% of all patients with ED presentations were subsequently hospitalized. Those participants with aerobics cases were generally female (76.6%) and aged 25 to 34 years old (35.3%), with injuries to the lower limbs (59.1%) and due to falls (57.9%). Resistance-training injuries increased significantly during the 8-year period (by 215.7%; 95% CI [133.5, 326.9]) and generally occurred in male participants (78.0%), in people aged 15 to 24 years old (36.4%), and with injuries to the upper limbs (45.1%) caused by being hit, struck, or crushed by weights or fellow exercisers (71.4%). The "other equipment" cases were equally distributed by gender; they occurred most commonly in people aged 15 to 24 years old (27.8%), with injuries to the lower limbs (41.5%) and due to falls (57.6%). Across all categories, dislocations, sprains, and strains were the most common injury types.

CONCLUSIONS

Fitness activity-related injury prevention strategies should be targeted at different subgroups according to the type of fitness activity being undertaken.

Rate of injury and subjective benefits of gravitational wellness weightlifting

Background

A preliminary study using the “gravitational wellness” weightlifting technique demonstrated this to be a unique technique for loading the musculoskeletal system with extremely high loads over short arcs. This leads to rapid weekly strength gains using 30-minute weekly training sessions. This study was designed to further assess the benefit–risk ratio of the gravitational wellness weightlifting technique.

Purpose

This descriptive/retrospective study examined musculoskeletal and well-being outcomes as well as injuries reported by consecutive participants at one gravitational wellness gym.

Materials and methods

All adults presenting for training at the Atlanta, Georgia, gravitational wellness system facility over a 6-month period were invited to participate. Data were obtained by telephone interview concerning the presenting complaint/objective of training, subjective outcome, weights lifted, and injuries incurred during training.

Results

Of the 77 participants contacted via telephone, 92% agreed to participate (male, n=40; female, n=31). The participants ranged in age from 18 years to 69 years, with a mean age of 48.6 years. Of these, 42 (59%) presented to the gym with the objective of improving a defined musculoskeletal issue. The modal of these was chronic low-back pain. The subjects realized improvement on a 5-point Likert scale of 4.2/5 for their presenting complaint, and improved by 4.27/5 in their overall subjective health. There were no injuries.

Conclusion

This study of consecutive participants at a gravitational wellness gym found that by lifting large weights over short arcs 3 0 minutes per week, participants significantly increased their strength, reduced their musculoskeletal pain, improve their subjective well-being, and reported a low rate of injury.