Potential Risk Factors For Injury Research Articles

Evaluation of Head and Body Kinematics Experienced During Parachute Opening Shock.

The U.S. Army conducts airborne operations in order to insert soldiers into combat. Military airborne operations are physically demanding activities with a unique loading environment compared with normal duties. A significant amount of research surrounding airborne operations has focused on assessing the incidence and type of associated injuries as well as the potential risk factors for injuries. During parachute opening shock and other high-acceleration events (e.g., fixed wing flight or vehicle crashes), the neck may be vulnerable to injury if inertial loads overcome the voluntary muscular control of the cervical spine and soft tissue structures. A recent epidemiological survey of sport skydivers showed that the neck, shoulders, and back were the most frequently reported sites of musculoskeletal pain. In addition, the survey indicated that wing loading (a measure of the jumper's weight divided by the size of the parachute canopy) was a potential contributing factor for developing musculoskeletal pain. Recently, there have been efforts to measure the severity of parachute opening shock as an additional potential risk factor for injury; however, no studies have measured both head and body accelerations and no studies have measured head or body angular rate during parachute opening shock. The purpose of this study was to measure and characterize the accelerations and angular rates of both the head and body during parachute opening shock as well as investigate potential factors contributing to higher severity opening shock, which may link to the development of musculoskeletal pain or injury. Data were collected from the U.S. Army Parachute Team, The Golden Knights, under an approved Medical Research and Material Command Institutional Review Board protocol. Subjects were instrumented with a helmet- and body-mounted sensor package, which included three angular rate sensors and three single-axis accelerometers each. Data were collected at 2,500 samples per second. Kruskal-Wallis tests were used to determine if helmet-mounted equipment (e.g., cameras), neck length, neck circumference, or wing loading (the ratio of jump weight to the size of the main parachute canopy) affected the accelerations or angular rates of the head or body. A total of 54 jumps conducted by 19 experienced free-fall jumpers were analyzed. For the head, the mean (± SD) resultant accelerations and angular rates were 5.8 (± 1.6) g and 255.9 (± 74.2) degrees per second (deg/s), respectively. For the body, the resultant accelerations and angular rates were 4.3 (± 1.5) g and 181.3 (± 61.2) deg/s, respectively. A wing loading above 1.4 pounds per square foot (lb/ft2) was found to have a significant effect on head (P = .001) and body (P = .001) resultant acceleration as well as body angular rate about the Y-axis (P = .001). There is evidence to suggest that wing loading has an influence on individual head and body resultant accelerations. However, no significant effects were found for the other variables (e.g., neck length and circumference, helmet-mounted equipment, etc.). Future research should focus on identifying additional factors that result in changes in accelerations and angular rates of the head and body during parachute opening shock events.

Novel Surface Mechanomyography Sensor Assessment Of Hamstrings Contraction During A Neuromuscular Control Screening Task

PURPOSE: Hamstring strain is a common injury among athletes. Asymmetries in muscle balance and activation are potential injury risk factors. Surface mechanomyography (sMMG) sensors are wearable devices that when applied across a muscle group provide a novel measurement of physical muscle output during a contraction. The purpose of this study is to assess 1) the relationship of sMMG’s muscle bulk displacement measurement to force generation and 2) sMMG detection of hamstrings contraction timing compared to the clinical standard method of electromyography (EMG). METHODS: Healthy, active individuals (mean age= 30.0 ±10.77 y, n=9, 6 males, 3 females) underwent hamstrings neuromuscular control assessment with simultaneous recording of EMG and sMMG by sensors applied to the right hamstrings. Subjects performed a series of 3 resisted “make-test” isometric hamstring curls against a hand-held dynamometer (HHD). Raw sMMG data and 6th order Butterworth filter and TKEO processed EMG data were used in timing analyses. Paired T-tests and a Pearson correlation assessed relationships between measurement modalities. RESULTS: Peak hamstrings muscle bulk displacement detected by sMMG (mean= 4.02 ±1.04 mm) positively correlated with HHD maximum force generation (mean= 28.84 ±12.13 lb), r2= 0.850. There was no significant difference in the timing duration of muscle contraction between EMG (mean= 4.443 ±0.573 s) and sMMG (mean= 4.469 ±0.623 s), p= 0.279. CONCLUSIONS: Results are consistent with physiologic expectations that increased physical muscle bulk displacement during a contraction is associated with greater force. Similarity in time signatures with EMG support findings of successful sMMG detection of hamstrings contraction (Figure 1). The sMMG sensor may be helpful for assessing hamstrings muscle performance of both force output and timing as part of neuromuscular control screening for injury prevention, rehabilitation monitoring, or return-to-sport readiness.

Listening to music while running alters ground reaction forces: a study of acute exposure to varying speed and loudness levels in young women and men.

Music listening while running enhances physiological and psychological features, resulting in a more enjoyable experience. The possible influence of music on ground reaction forces (GRF) during running, however, is unknown. Considering the 'distracting' role of music on runner's attention, we hypothesized that music would cover foot impacts against the ground. This study verified such hypothesis by testing the effects of different music volumes while running at different velocities. Fifty fit volunteers (F:M = 22:8; 23 ± 2 years) performed 2-min running stints over 3 random conditions (80-dB, 85-dB music; 'no music'), at 3 velocities (8, 10, 12 km/h). Participants ran on a sensorized treadmill that recorded GRF during all experiments. Listening to 85-dB music resulted in greater GRF at 8 (p = 0.0005) and 10 km/h (p = 0.04) but not 12 km/h (p = 0.35) and not with 80-dB volume. Gender-based analyses revealed significant Condition × gender interactions only for 85-dB music vs. 'no music'. Bonferroni-adjusted comparisons revealed significant music-induced increases in GRF only in men at 8 km/h (+ 4.1 kg/cm2, p < 0.0005; women: + 0.8 kg/cm2, p = 0.47) and 10 km/h (+ 3.3 kg/cm2, p = 0.004; women: + 0.8 kg/cm2, p = 0.51) but not at 12 km/h. In active men, listening to loud music while running results in increased GRF, whereas no effect was observed in women. The lack of music effect in women may be related to structural factors, such as larger hip width-to-femoral length ratio, possibly resulting in different loading patterns. The present preliminary findings introduce high-volume music listening as a new potential risk factor for injury in young runners.

Retrospective Study of Risk Factors and the Prevalence of Injuries in HIFT.

The aim of this study was to investigate the risk factors and the incidence of injuries in high-intensity functional training (HIFT) practitioners. A survey was administered to 213 HIFT practitioners. Participants reported the number of injuries, the location of the injuries, and training exposure during the preceding six months and answered questions regarding potential risk factors for injury. We found there were 7.1 injuries for every 1000 hours of training. In addition, we found that individuals with experience in the modality (>2 years) were 3.77 times more likely to be affected by injury when compared with beginner individuals (<6 months) (CI95%=1.59-8.92; p=0.003). When the analysis was performed only for the competitive level, we found that practitioners competing at the national level were 5.69 times more likely to experience an injury than competitors who do not compete (CI95%=1.10-29.54; p=0.038). We also found that the injuries mainly affect the shoulder and lumbar regions. It was possible to conclude that subjects with a higher level of experience in the modality are more likely to be affected by injuries and that the shoulder and lumbar areas are most likely to be injured during HIFT.

Injury rate and risk factors among small-scale gold miners in Ghana

BackgroundTo determine the potential risk factors for injury, estimate the annual injury rate and examine the safety perceptions, and use of personal protective equipment among small-scale gold miners in Ghana.MethodsA cross-sectional survey was carried out with 494 small-scale gold miners from four major mining districts in Ghana. A household-based approach was used to obtain a representative sample of miners. The study was conducted from June 2015 to August 2016. A systematic sampling technique was used to select households and recruit respondents to interview. Miners were asked about any mining related injury that they had sustained in the past year. A logistics regression model was employed to examine the association between risk factors and injury. Data were analyzed with STATA version 14.0.ResultsThe annual incidence rate of mining-related injury was 289 per 1000 workers. Injuries were mainly caused by machinery/tools 66(46.1%), followed by slip/falls 46(32.2%). The major risk factor for injury was underground work (adjusted odds ratio for injury 3.19; 95% CI = 1.42–7.20) compared with surface work. Higher education levels were protective, with adjusted odds ratios of 0.48 (95% CI = 0.24–0.99) for middle school education and 0.38 (95% CI 0.17–0.83) for secondary school compared with no schooling. Only 15(3.0%) of miners reported to have had safety training in the past year and 105(21.3%) indicated that there were safety regulations at their work place. A moderate number of workers reported using work boots 178(36.0%) and hand gloves 134(27.1%), but less than 10% of workers used other personal protective equipment.ConclusionThe annual injury incidence rate among small-scale gold miners is high. Potential targets for improving safety include increasing safety training, increasing use of personal protective equipment, and better understanding potential changes that can be made in the machinery and tools used in small-scale mining, which were associated with almost half of all injuries.

Surgical Approach Impacts Posterior Femoral Cutaneous Nerve Outcomes After Proximal Hamstring Repair.

The goal of this study was to characterize the risk of intraoperative injury to the posterior femoral cutaneous nerve and to evaluate potential risk factors for injury during surgical repair of proximal hamstring injuries. Retrospective cohort study. Single tertiary referral center. The cohort consisted of all patients presenting to a single institution with a proximal hamstring avulsion injury who were managed with surgical repair between January 1, 2000 and August 1, 2016. A total of 67 patients were included in the cohort. Variables assessed for their association with postoperative numbness in the distribution of the posterior femoral cutaneous nerve included age, sex, body mass index, mechanism of injury, time to surgical repair, and incision used. The primary outcome of interest was neurologic symptoms referable to the posterior femoral cutaneous nerve. Postoperatively, 13 patients (19%) developed new numbness in the distribution of the posterior femoral cutaneous nerve. One patient reported neuropathic pain and paresthesias associated with the numbness. The use of a gluteal crease incision was the only predictive factor for postoperative numbness in the posterior femoral cutaneous nerve distribution (odds ratio 8.67; 95% confidence interval, 2.30-42.80; P = 0.001). The current study provides data that can be used in discussing the risks and benefits of surgical repair with patients and when weighing the pros and cons of using a gluteal crease versus longitudinal incision.

Research on the needs of vocational high school students for injury prevention and emergency skills education

Background: Objective to investigate the needs of junior high school students for injury prevention awareness and emergency skills education, so as to provide reference basis for junior high school students to carry out injury prevention work. Methods: A total of 1079 vocational middle school students were selected by stratified cluster sampling. The content of the questionnaire includes: basic demographic information, cognition of injury-related risk factors, demand for injury prevention education, mastery of first aid skills, etc. Results: 76.2% believed that there were potential risk factors leading to injury accidents in life, 397 (36.8%) chose yes, rarely, 303 (28.1%) chose yes, generally, and 122 (11.3%) chose yes, many .Among the places considered most vulnerable to injury, the top five were road/street, off-campus sports ground, business district, school and residential district, with 79.1%, 41.6%, 33.1%, 29.2% and 19.6% respectively. The potential risk factors considered by students are divided into four aspects. The proportion of vocational middle school students in the judgment and selection of potential risk factors are lack of safety awareness (54.9%) and excessive learning pressure (41.2%) respectively. Parents ignore their children (34.0%) and family relationship is not harmonious (31.3%) were the top two risk factors for potential injury to the family. The top two risk factors for potential injury in schools were bad school atmosphere (37.7%) and lack of school safety education (36.9%).For potential hazardous environmental factors, unsafe road environment (64.8%) and unsafe sports facilities (44.8%) ranked top two.89.0% of the students think it necessary to attend schools or other institutions to carry out safety education or activity, hope schools provide injury prevention education aspect, the top six were bullying (85.6%), food hygiene (80.3%), traffic injuries (74.4%), fraud (65.1%), electric shock (65.1%) and first aid (63.5%), especially the bullying of these safety education.78.9% of the students said they had received first aid training, and CPR (86.5%), first aid for drowning (49.4%), bandaging (42.2%) and hemostasis (42.0%) were the top four first aid skills of the middle school students surveyed. The most common reasons for not mastering first aid skills were forgetting after learning (33.5%) and too short training time (29.7%). Conclusion: Junior high school students need to improve their education on potential injury risk factors in life and emergency treatment in the face of injury.It is necessary to carry out injury prevention and emergency skills education among high school students in vocational schools.

Surgical quality in organ procurement during day and night: an analysis of quality forms

ObjectivesTo analyse a potential association between surgical quality and time of day.DesignA retrospective analysis of complete sets of quality forms filled out by the procuring and accepting surgeon on organs...

Running velocity has no influence on lower limb mechanical asymmetry

Introduction: In running-related literature, the concept of asymmetry has been studied as a potential injury risk factor as well as a basis for appropriate programming of injury prevention, return to play and performance enhancement interventions. A clearer understanding of the expected magnitude/range of asymmetry for a wide spectrum of running velocities and a large number of running mechanical variables in the same cohort is required. The aim of this study was to examine the effect of running velocity upon magnitude and range of asymmetry in the main spatio-temporal and spring-mass characteristics of treadmill running at constant velocity in well-trained distance runners.

A prospective investigation to evaluate risk factors for lower extremity injury risk in male youth soccer players.

There is an inherent risk of injury in male youth football; however, pertinent risk factors for injury have yet to be examined. This study used a prospective cohort design with 357 elite male youth football players (aged 10-18years) assessed during the preseason period and then monitored during the season recording all non-contact lower extremity injuries. Screening tests included single leg hop for distance (SLHD); 75% of maximum hop and stick (75%Hop); single leg countermovement jump (SLCMJ); and the tuck jump assessment (TJ). Players were divided into subgroups based on chronological age. SLCMJ peak landing vertical ground reaction force (pVGRF) asymmetry was the most prominent risk factor (U11-U12s, OR 0.90, P=.04; and U15-U16s, OR 0.91, P<.001). Maturational offset (OR 0.58, P=.04), lower right leg SLCMJ pVGRF relative to body weight (OR 0.36, P=.03), and advanced chronological age (OR 3.62, P=.04) were also significantly associated with heightened injury risk in the U13-U14s, U15-U16s, and U18s, respectively. Univariate analyses showed combinations of anthropometric and movement screening risk factors were associated with heightened risk of lower extremity injury; however, there was variability across the different chronological age groups. Greater SLCMJ pVGRF asymmetry, lower right leg SLCMJ pVGRF %BW, later maturation, and advanced chronological age are potential risk factors for injury in elite male youth football players, although the strength of these relationships was often low to moderate. In addition, risk factors are likely to change at different stages of development.

Evaluation of the US Army Special Forces Tactical Human Optimization, Rapid Rehabilitation, and Reconditioning Program.

We sought to assess the rehabilitation process, training, performance, and injury rates among those participating and not participating in the Tactical Human Optimization, Rapid Rehabilitation, and Reconditioning (THOR3) program and determine injury risk factors. A survey inquiring about personal characteristics, injuries, physical performance, and THOR3 participation during the previous 12 months was administered to Army Special Operations Forces (SOF) Soldiers. Based on responses to physical training, Soldiers were categorized into three groups: a traditional physical training (TPT) group, a cross-training (CT) group, and a THOR3 group. To identify potential injury risk factors, risk ratios and 95% confidence intervals (95% CIs) were calculated. Backward- stepping multivariable logistic regression models were used to assess key factors associated with injury risk. The survey was completed by 328 male Soldiers. Most of the Soldiers (62%) who scheduled an appointment with the physical therapist were seen within 1 day. Self-reported injury rates for the TPT, CT, and THOR3 groups were 70%, 52%, and 48%, respectively. When controlling for personal characteristics, unit training, and fitness, the TPT group had a marginally higher risk of being injured than the THOR3 group (odds ratio [OR], 2.72; 95% CI, 0.86-8.59; p = .09). Soldiers who did not perform any unit resistance training (ORnone/90-160 min, 3.62; 95% CI, 1.05-12.53; p = .04) or the greatest amount of resistance training (OR>160 min/90-160 min, 3.44; 95% CI, 1.64-7.20; p < .01) were more likely to experience an injury than the moderate-resistance training group. THOR3 appears to offer human performance optimization/injury prevention advantages over other SOF human performance programs.

Risk factors for football injuries in young players aged 7 to 12years.

Football (soccer) is very popular among children. Little is known about risk factors for football injuries in children. The aim was to analyze potential injury risk factors in 7- to 12-year-old players. We collected prospective data in Switzerland and the Czech Republic over two seasons. Coaches reported exposure of players (in hours), absence, and injury data via an Internet-based registration system. We analyzed time-to-injury data with extended Cox models accounting for correlations on team- and intra-person levels. We analyzed injury risk in relation to age, sex, playing position, preferred foot, and regarding age-independent body height, body mass, and BMI. Further, we analyzed injury risk in relation to playing surface. In total, 6038 player seasons with 395295hours of football exposure were recorded and 417 injuries occurred. Injury risk increased by 46% (Hazard Ratio 1.46 [1.35; 1.58]; P<.001) per year of life. Left-footed players had a higher injury risk (Hazard Ratio 1.53 [1.07; 2.19]; P=.02) for training injuries compared to right-footed players. Injury risk was increased in age-adjusted taller players (higher percentile rank). Higher match-training ratios were associated with a lower risk of match injuries. Injury risk was increased on artificial turf (Rate Ratio 1.39 [1.12; 1.73]; P<.001) and lower during indoor sessions (Rate Ratio 0.68 [0.52; 0.88]; P<.001) compared to natural grass. Age is known as a risk factor in older players and was confirmed to be a risk factor in children's football. Playing surface and leg dominance have also been discussed previously as risk factors. Differences in injury risks in relation to sex should be investigated in the future.

Language Barrier as a Risk Factor for Injuries From Patient Violence Among Direct Care Workers in Home Settings: Findings From a U.S. National Sample.

This study explored potential risk factors for injuries from patient violence among direct care workers in U.S. homes (DCWHs). A national probability sample of 3,377 DCWHs including home health and personal care aides was analyzed using complex sample analysis and generalized estimating equation. Injury from violence was defined as a workrelated injury sustained by aggression, violence, or abuse that was reported to the agency, required medical attention or resulted in absenteeism from work. An association between suffering an injury from patient violence and having a language barrier with patients was noted (OR = 4.44; 95% CI = 1.57, 12.56; p = .005). Findings illuminate the importance of homecare providers to match language between DCWHs and patients to reduce patient violence and improve quality of care in the home setting.

Time-dependent postural control adaptations following a neuromuscular warm-up in female handball players: a randomized controlled trial

BackgroundFemale handball athletes are at a particular risk of sustaining lower extremity injuries. The study examines time-dependent adaptations of static and dynamic balance as potential injury risk factors to a specific warm-up program focusing on neuromuscular control.MethodsFourty one (24.0 ± 5.9 years) female handball athletes were randomized to an intervention or control group. The intervention group implemented a 15-min specific neuromuscular warm-up program, three times per week for eleven weeks, whereas the control group continued with their regular warm-up. Balance was assessed at five time points. Measures included the star excursion balance test (SEBT), and center of pressure (COP) sway velocity during single-leg standing.ResultsNo baseline differences existed between groups in demographic data. Adherence to neuromuscular warm-up was 88.7 %. Mean COP sway velocity decreased significantly over time in the intervention group (−14.4 %; p < .001), but not in the control group (−6.2 %; p = 0.056). However, these effects did not differ significantly between groups (p = .098). Mean changes over time in the SEBT score were significantly greater (p = .014) in the intervention group (+5.48) compared to the control group (+3.45). Paired t-tests revealed that the first significant balance improvements were observed after 6 weeks of training.ConclusionsA neuromuscular warm-up positively influences balance variables associated with an increased risk of lower extremity injuries in female handball athletes. The course of adaptations suggests that a training volume of 15 min, three times weekly over at least six weeks produces measurable changes.Trial registrationRetrospectively registered on 4th October 2016. Registry: clinicaltrials.gov. Trial number: NCT02925377.Electronic supplementary materialThe online version of this article (doi:10.1186/s13102-016-0058-5) contains supplementary material, which is available to authorized users.

Injuries Among Italian DanceSport Athletes: A Questionnaire Survey.

During training and competition, athletic dancers perform complex artistic movements that can lead to stress on the musculoskeletal system, making them subject to high risk of injury. The purpose of this study was to evaluate the prevalence, location, and nature of musculoskeletal injuries among dancesport athletes and to identify potential risk factors for injury. This cross-sectional study was performed at several national dancesport meetings in Italy. All 168 dancesport athletes who participated at the meetings were invited to complete a questionnaire related to injuries they may have suffered during the previous year; other information collected included demographic data (age, sex, height, weight), dance participation (discipline, categories), training (training duration, years since starting to dance), and injury (location, etiology). Of the 168 dancers, 153 completed the questionnaire. Of the 102 injuries reported, 73 athletes (47.7%) reported at least 1 injury. The locations of the injuries were the lower limbs (n=75, 73.5%), upper limbs (8, 7.8%), and spine (19, 18.7%). Significant differences were found in the injury location (p<0.01) as well as the nature of the injury (p<0.01). No significant differences were found between injured and non-injured athletes in demographic data, dance participation, and training variables (p>0.05). The results indicate that about half of the dancers reported at least 1 injury, with these being located particularly in the lower limbs and predominantly strain and sprain injuries. To reduce the prevalence of injuries, a prevention program may be indicated, with future research needed to identify appropriate strategies to prevent injuries.

Injuries to Professional and Amateur Kickboxing Contestants: A 15-Year Retrospective Cohort Study.

Background:Kickboxing is a group of full-contact combat sports that allows both kicking and punching from a standing position. Despite its popularity, there is a scarcity of published data elucidating the injury epidemiology in kickboxing.Purpose:To determine the injury incidence, describe the injury pattern, and identify potential risk factors for injury in kickboxing.Study Design:Descriptive epidemiology study.Methods:Data describing fight outcomes and injuries sustained during professional and amateur kickboxing contests over a 15-year period were obtained from the official records of the Nevada Athletic Commission, United States. Injury incidence rates and rate ratios were calculated with 95% confidence intervals (95% CIs) per 1000 athlete-exposures (AEs) and per 1000 minutes of exposure. The injury pattern was described using frequencies and proportions of injuries by anatomic region and type of injury. In addition, Poisson mixed-effects generalized linear modeling was used to examine the multivariate relationships between injury incidence rates and potential risk factors.Results:The sample consisted of 481 unique fighters competing across 57 events, 976 AEs, 9562 minutes of exposure, and 380 injuries. The mean ± SD age of the fighters was 29.0 ± 5.3 years (range, 15-48 years). The overall injury incidence rates were 390.1 injuries (95% CI, 351.9-431.4) per 1000 AEs and 39.7 injuries (95% CI, 35.8-43.9) per 1000 minutes of exposure. The most commonly injured anatomic regions were the head (57.8%) and lower extremity (26.1%), while the most common types of injury were laceration (70.6%) and fracture (20.6%). Professional fighters were 2.5 times more likely to get injured compared with amateurs (rate ratio, 2.51; 95% CI, 1.39-4.55), while defeated fighters were 3.5 times more likely to get injured compared with winners (rate ratio, 3.48; 95% CI, 2.73-4.44).Conclusion:Injuries are frequent and often significant in kickboxing, and better injury surveillance is strongly recommended. The scarcity of good-quality epidemiological data in kickboxing, especially pertaining to the severity of injuries, underscores the urgent need for further research, whereupon evidence-informed sport safety and injury prevention policies can be developed.

On the question of the frequency of mechanical eye trauma in senile patients in Azerbaijan

The article presents the results of the trauma of the eyes for a period of 10 years (2000-2009) in 601 hospitalized patients of 50 (min)-92 years (max) years old. By the age criteria, the eye injury most often occurred in senile patients (50.9%), the proportion of senile patients over time decreases due to the increase of middle-aged patients. By decades of age groups, there is a slight excess of the frequency injury index at the age of 51 to 60 compared with age from 61 to 70. As potential risk factors for injury the age-related changes in quality of vision cannot be excluded. Men were 438 (72.9%), women 163 (27.1%) with an average age of males 63.4 +/- 0.4 years, females--67.1 +/- 0.8. Timely provision of expert care, as a visual criterion, reflected the time factor of patients' addressing to the hospital. The analysis of the causes of eye injuries confirmed their diversity. The traumas received by the patients while falling (14.5 +/- 1.4) including--frequent due to the aggravation factor of the patient that determines both the injury and delayed treatment are noteworthy. According to addressing to the hospital, primary emergency aid was rendered on the first day only to 15.3 +/- 1.5% patients, within 1 to 3 days 34.9 +/- 1.9% were hospitalized, 4-7 days--10.5 +/- 1.2%, 8-14 days--7.5 +/- 1.1%. The problem of eye injury in senile patients remains topical, given the frequency of eye injuries in senile patients, given the high probability of somatic aggravation of the patients as a potential risk factor for injury, delayed treatment, which makes the problem of eye trauma in senile patients the one that demands increased and due attention.

Descriptive analysis of kinematics and kinetics of catchers throwing to second base from their knees

In order to decrease the amount of time that it takes the catcher to throw the ball, a catcher may chose to throw from the knees. Upper extremity kinematics may play a significant role in the kinetics about the elbow observed in catchers throwing from the knees. If relationships between kinematics and kinetics exist then the development of training and coaching instruction may help in reduced upper extremity injury risk. Twenty-two baseball and softball catchers (14.36±3.86years; 165.11±17.54cm; 65.67±20.60kg) volunteered. The catchers exhibited a less trunk rotation (5.6±16.2°), greater elbow flexion (87.9±21.4°) and decreased humeral elevation (71.1±12.3°) at the event of maximum shoulder external rotation as compared to what has previously reported in catchers. These variables are important, as they have previously been established as potential injury risk factors in pitchers, however it is not yet clear the role these variables play in catchers’ risk of injury. A positive relationship between elbow varus torque during the deceleration phase and elbow flexion at MIR was observed (r=0.609; p=0.003). Throwing from the knees reduces a catcher’s ability to utilize the proximal kinetic chain and this may help to explain why their kinematics and kinetics differ from what has previously been presented in the literature.

Decrease in eccentric quadriceps and hamstring strength in recreational alpine skiers after prolonged skiing

BackgroundTo effectively prevent injury in recreational alpine skiing, it is important to identify modifiable risk factors that can be targeted through exercise and training. Fatigue is a potential risk factor...

No association between surface shifts and time-loss overuse injury risk in male professional football.

To investigate frequent surface shifts and match play on an unaccustomed surface as potential risk factors for injury in Scandinavian male professional football. Prospective cohort study. Thirty two top-division clubs (16 Swedish, 16 Norwegian) were followed during seasons 2010 and 2011. The influence from (1) number of surface shifts (between artificial turf and grass) during five-match sequences, and (2) match play on an unaccustomed surface (other surface than on the home venue) on subsequent overuse injury risk was evaluated with generalized estimating equations (GEE). GEE results are presented with risk ratios and 95% confidence interval (CI). Injury rate was expressed as time loss injuries/1000h, and compared between groups with a rate ratio and 95% CI. No association was found between the number of surface shifts and subsequent overuse injury risk (risk ratio 1.01, 95% CI 0.91-1.12). Furthermore, no difference was seen in subsequent overuse injury risk after match play on unaccustomed compared with accustomed surface (risk ratio 1.04, 95% CI 0.78-1.38). Grass clubs (grass installed at home venue) had a lower match injury rate when playing away matches on artificial turf compared with away matches on grass (rate ratio 0.66, 95% CI 0.40-0.89). This study showed no association between surface shifts or playing matches on an unaccustomed surface and time-loss injury risk in professional football, suggesting that clubs and players can cope with such surface transitions.