Lower Extremity Overuse Injuries Research Articles

A Closer Look at Localized and Distant Pressure Pain Hypersensitivity in People With Lower Extremity Overuse Soft-Tissue Painful Conditions: A Systematic Review and Meta-Analysis.

The nociceptive pain processing of soft-tissue overuse conditions is under debate because no consensus currently exists. The purpose of this meta-analysis was to compare pressure pain thresholds (PPTs) in symptomatic and distant pain-free areas in 2 groups: participants with symptomatic lower extremity overuse soft-tissue conditions and controls who were pain free. Five databases were searched from inception to December 1, 2021, for case-control studies comparing PPTs between individuals presenting with symptomatic lower extremity tendinopathy/overuse injury and controls who were pain free. Data extraction included population, diagnosis, sample size, outcome, type of algometer, and results. The methodological quality (Newcastle-Ottawa Quality Assessment Scale) and evidence level (Grading of Recommendations Assessment, Development, and Evaluation) were assessed. Meta-analyses of symptomatic, segmental related, and distant pain-free areas were compared. After screening 730 titles and abstracts, a total of 19 studies evaluating lower extremity overuse conditions (Achilles or patellar tendinopathy, greater trochanteric pain syndrome, plantar fasciitis, and iliotibial band syndrome) were included. The methodological quality ranged from fair (32%) to good (68%). Participants with lower extremity overuse injury had lower PPTs in both the painful and nonpainful areas, mirrored test-site, compared with controls (affected side: mean difference [MD] = -262.92kPa, 95% CI = 323.78 to -202.05kPa; nonaffected side: MD = -216.47kPa, 95% CI = -304.99 to -127.95kPa). Furthermore, people with plantar fasciitis showed reduced PPTs in the affected and nonaffected sides at segmental-related (MD = -176.39kPa, 95% CI = -306.11 to -46.68kPa) and distant pain-free (MD = -97.27kPa, 95% CI = 133.21 to -61.33kPa) areas compared with controls. Low- to moderate-quality evidence suggests a reduction of PPTs at the symptomatic area and a contralateral/mirror side in lower extremity tendinopathies and overuse conditions compared with pain-free controls, particularly in plantar fasciitis and greater trochanteric pain syndrome. Participants with plantar fasciitis showed a reduction of PPTs on the affected and non-affected sides at a segmental-related area (very low-quality evidence) and at a remote asymptomatic area (moderate-quality evidence). Some overuse peripheral pain conditions may be more associated with pressure pain sensitivity than others. Accordingly, examination and identification of conditions more peripherally, centrally, or mixed mediated could potentially lead to more specific and different treatment strategies.

Machine-learned-based prediction of lower extremity overuse injuries using pressure plates.

Although running has many benefits for both the physical and mental health, it also involves the risk of injuries which results in negative physical, psychological and economical consequences. Those injuries are often linked to specific running biomechanical parameters such as the pressure pattern of the foot while running, and they could potentially be indicative for future injuries. Previous studies focus solely on some specific type of running injury and are often only applicable to a gender or running-experience specific population. The purpose of this study is, for both male and female, first-year students, (i) to predict the development of a lower extremity overuse injury in the next 6 months based on foot pressure measurements from a pressure plate and (ii) to identify the predictive loading features. For the first objective, we developed a machine learning pipeline that analyzes foot pressure measurements and predicts whether a lower extremity overuse injury is likely to occur with an AUC of 0.639 and a Brier score of 0.201. For the second objective, we found that the higher pressures exerted on the forefoot are the most predictive for lower extremity overuse injuries and that foot areas from both the lateral and the medial side are needed. Furthermore, there are two kinds of predictive features: the angle of the FFT coefficients and the coefficients of the autoregressive AR process. However, these features are not interpretable in terms of the running biomechanics, limiting its practical use for injury prevention.

Plank Times and Lower Extremity Overuse Injury in Collegiate Track-and-Field and Cross Country Athletes.

Trunk muscle endurance has been theorized to play a role in running kinematics and lower extremity injury. However, the evidence examining the relationships between static trunk endurance tests, such as plank tests, and lower extremity injury in athletes is conflicting. The purpose of this study was to assess if collegiate cross country and track-and-field athletes with shorter pre-season prone and side plank hold times would have a higher incidence of lower extremity time-loss overuse injury during their competitive sport seasons. During the first week of their competitive season, 75 NCAA Division III uninjured collegiate cross country and track-and-field athletes (52% female; mean age 20.0 ± 1.3 years) performed three trunk endurance plank tests. Hold times for prone plank (PP), right-side plank (RSP) and left-side plank (LSP) were recorded in seconds. Athletes were followed prospectively during the season for lower extremity overuse injury that resulted in limited or missed practices or competitions. Among the athletes, 25 (33.3%) experienced a lower extremity overuse injury. There were no statistically significant mean differences or associations found between PP, RSP or LSP plank test hold times (seconds) and occurrence of lower extremity overuse injury. In isolation, plank hold times appear to have limited utility as a screening test in collegiate track-and-field and cross country athletes.

Central vs. Peripheral Vision during a Singe-Leg Drop Jump: Implications of Dynamics and Patellofemoral Joint Stress

Landing on a single-leg without receiving direct visual information (e.g., not looking at the ground) may increase the risk of injury. We examined whether visual focus contributed to the changing lower-extremity dynamics and patellofemoral joint stress during a single-leg drop jump task. Twenty healthy volunteers visited the laboratory for three separate sessions. During each session, participants randomly performed either of two types of a single-leg drop jump task from a 30 cm high wooden box. Subsequently, participants looked at the landing spot (central vision condition) or kept their heads up (peripheral vision condition) when performing the task. Sagittal and frontal plane lower-extremity joint angles and joint moments (in the ankle, knee, and hip), including the vertical ground reaction force, and patellofemoral joint stress during the first landing phase (from initial contact to peak knee flexion) were compared. Greater ankle inversion and hip adduction were observed when landing with the peripheral vision condition. However, the magnitudes were negligeable (Cohen’s d effect size <0.35). No statistical difference was observed in other comparisons. Landing on a single-leg from a 30 cm height without receiving full visual attention (peripheral vision condition) does not increase the risk of lower-extremity traumatic and overuse injuries.

Peak Plantar Pressure as a Risk Factor for Lower Extremity Overuse Injury Among Infantry Soldiers

Abstract The majority of reported injuries among military populations are injuries due to cumulative repetitive microtrauma — overuse injuries. Plantar pressure measurement is a simple tool to analyse lower limb biomechanics through the assessment of forces applied to the foot. This study aimed to determine the relation between peak plantar pressure and lower extremity overuse. Sixty-six active-duty infantry male soldiers, with mean age 29.7 years (range 22–40 years), and mean service time 5.2 years (range 1–15 years) participated. The highest peak plantar pressure (PPP) at the forefoot occurred at the hallux (cases: 50.82 n/cm2, SD = 38.84; control: 34.39 n/cm2, SD= 28.03) and 3rd metatarsal head (cases: 54.40 n/cm2, SD = 33.83; control: 49.16 n/cm2, SD=28.87). The study demonstrated elevated PPP among cases. Statistically significant results were found at the hallux (χ2(1) = 6.8; p = 0.01), medial heel (χ2(1) = 5.18; p = 0.02) and lateral heel (χ2(1) = 12.12; p < 0.01) regions. The results show that plantar pressure assessment could be used as a useful screening tool for early lower extremity overuse injury detection.

Altered Dynamic Postural Stability and Joint Position Sense Following British Army Foot-Drill.

Impaired proprioceptive acuity negatively affects both joint position sense and postural control and is a risk factor for lower-extremity musculoskeletal injury in athletes and military personnel. British Army foot-drill is an occupational military activity involving cyclical high impact loading forces greater than those observed in athletes during high level plyometrics. Foot-drill may contribute to the high rates of lower-extremity overuse injuries observed in recruits during basic training. There is limited research investigating foot-drill specific injury risk factors in women, despite greater incidences of musculoskeletal injury reported in women (522 vs. 417 per 1,000 personnel, OR: 1.53) when compared to men during basic training. This study aimed to quantify changes in ankle joint proprioception and dynamic postural stability following a period of British Army foot-drill. Fourteen women of similar age to British Army female recruits underwent pre-post foot-drill measures of frontal plane ankle joint position sense (JPS) and dynamic postural stability using the dynamic postural stability index (DPSI). Passive ankle JPS was assessed from relative test angles of inversion 30% (IN30%) and eversion 30% (EV30%) and IN60% of participants range of motion using an isokinetic dynamometer. The DPSI and the individual stability indices (medio-lateral [MLSI], anterior-posterior [APSI], and vertical [VSI]) were calculated from lateral and forward jump-landing conditions using force plates. Foot-drill was conducted by a serving British Army drill instructor. Significantly greater absolute mean JPS error for IN30% and EV30% was observed post foot-drill (p ≤ 0.016, d ≥ 0.70). For both the lateral and forward jump-landing conditions, significantly greater stability index scores were observed for MLSI, APSI, and DPSI (p ≤ 0.017, d ≥ 0.52). Significantly greater JPS error and stability index scores are associated with the demands of British Army foot-drill. These results provide evidence that foot-drill negatively affects lower-extremity proprioceptive acuity in recruit age-matched women, which has implications for increased injury risk during subsequent military physical activity, occurring in a normal training cycle.

Relationship Between Jump-Landing Kinematics and Lower Extremity Overuse Injuries in Physically Active Populations: A Systematic Review and Meta-Analysis.

Lower extremity overuse injuries are common in athletes participating in sports with repeated bouts of landing manoeuvres. Biomechanical alterations during landing may be associated with these types of injuries. The objective of this systematic review with meta-analysis was to summarise and determine the relationship between kinematic alterations during a landing task and the development of lower extremity overuse injuries in physically active populations. PubMed, Embase, Web of Science, CINAHL, and SPORTDiscus were consulted up to and including February 2020. Cohort, cross-sectional or case-control studies were included if they investigated the relationship between three-dimensional (3D) landing kinematics in physically active populations and either new incidence or a history of lower extremity overuse injuries. Twenty-three studies that investigated 3D landing kinematics in subjects with either patellar tendinopathy (PT), patellofemoral pain (PFP), exertional medial tibial pain (EMTP) or groin overuse injury met the inclusion criteria. Based on this systematic review, there is evidence for decreased knee flexion range of motion (ROM) and increased knee abduction ROM during landing as risk factors for PFP. For PT, risk factors are poorly understood. Furthermore, the meta-analysis demonstrated significantly greater hip adduction at initial contact (IC) (p = 0.02), greater knee internal rotation at IC (p < 0.001), greater peak knee external rotation (p = 0.05) and less ankle dorsiflexion at peak vertical ground reaction force (vGRF) (p = 0.05) in subjects with knee overuse injuries compared to healthy controls. There is evidence of increased trunk, hip and knee transversal ROM as risk factors for EMTP. Groin injuries are associated with greater pelvic and hip frontal and transversal plane ROM in the injured group compared to the healthy controls. The results of this systematic review and meta-analysis provide preliminary evidence for impaired landing kinematics associated with lower extremity overuse injuries. Excessive frontal and transversal plane movements during landing manoeuvres might increase impact and tensile forces resulting in lower extremity overuse injuries. This systematic review was registered in the PROSPERO international prospective register of systematic reviews (ID = CRD42019135602).

Sport specialization is associated with upper-extremity overuse injury in high school baseball players

Sport specialization is increasingly common in youth sports and is a risk factor for lower-extremity overuse injuries. However, limited data existon whether specialization is associated with upper-extremity (UE) overuse injuries, specifically in youth baseball players. We hypothesized that specialization in baseball and being a pitcher would be associated with poorer arm health and UE overuse injury history in the previous year. During the 2019 spring baseball season, 551 high school baseball athletes (aged 15.9 ± 1.3 years) from 3 states (Alabama, n = 200; California, n = 188; and Michigan, n = 163) completed an anonymous questionnaire. Athletes were recruited from 5 high schools in each state, with schools matched based on factors that influence specialization rates. The questionnaire consisted of (1) demographic characteristics, (2) baseball participation information (including sport specializationstatus), and (3) throwing-arm health and UE injury history in the previous 12 months. Throwing-arm health was assessed using the Youth Throwing Score (YTS), a validated and reliable outcome measure for youth baseball players. Multivariate regression analyses were used to examine the association between variables of interest and the YTS or UE overuse injury history, adjusting for covariates. After adjustment for covariates, highly specialized athletes were more likely to report a UE overuse injury in the previous year compared with low-specialization athletes (odds ratio [OR], 3.77; 95% confidence interval [CI], 1.39-10.2, P = .009). Both athletes who reported playing baseball for more than 8 months per year (OR, 2.03; 95% CI, 1.12-3.65; P = .019) and athletes who reported being a pitcher (OR, 2.11; 95% CI, 1.20-3.72; P = .010) were more likely to report a history of UE overuse injury. Highly specialized players reported lower (worse) YTS values compared with low-specialization players (least-squares mean estimate ± standard error, 56.5 ± 1.1 vs. 53.3 ± 0.7; P = .034). Players who reported pitching as one of their positions scored worse on the YTS than non-pitchers (least-squares mean estimate ± standard error, 51.6 ± 0.8 vs. 57.2 ± 0.6; P < .001). Although baseball recommendations that discourage sport specialization are widely available for parents, athletes, and coaches, high rates of sport specialization were reported in our sample. We found that being highly specialized in baseball was associated with UE overuse injury history and worse throwing-arm health in high school baseball athletes. Continued education for baseball parents, athletes, and coaches is necessary to raise awareness of the risks associated with high specialization.

Early Sport Specialization and Subjective Hip and Groin Dysfunction in Collegiate Ice Hockey Athletes.

Sport specialization is a popular trend among youth athletes that has been associated with an increased risk for developing lower extremity overuse injuries. Early ice hockey specialization may contribute to the high rates of noncontact and overuse hip and groin injuries in collegiate ice hockey athletes. To examine the effects of high, moderate, and low levels of sport specialization on subjective hip and groin dysfunction in collegiate ice hockey athletes. Retrospective cohort study. Data were collected during the midseason of the 2018-2019 hockey season at a local ice hockey arena. National Collegiate Athletic Association Division III and club ice hockey players from Midwestern college programs (n = 187; 81 women, 106 men). Participants were stratified into high-, moderate-, and low-specialization groups based on ice hockey participation before grade 9 of high school. The 6 subscales of the Hip and Groin Outcome Score questionnaire were used to assess current subjective hip and groin dysfunction. The high-specialization group had lower scores than the low-specialization group on the Symptoms (P = .001), Pain (P = .003), Activities of Daily Living (P = .001), Sport and Recreation (P = .014), and Quality of Life (P = .002) subscales. The moderate-specialization group had lower scores than the low-specialization group on the Symptoms (P = .015) and Activities of Daily Living (P = .006) subscales. Collegiate ice hockey athletes who were highly specialized before high school reported greater current hip and groin pain, symptoms, and dysfunction during activities of daily living and sport and recreation and lower current hip- and groin-related quality of life compared with low-specialization ice hockey athletes. Early ice hockey specialization may be detrimental to hip and groin function in collegiate ice hockey athletes.

Definition of the lower extremity overuse: A review

Injuries of the lower extremity overuse are common among different adult populations with high physical demands such as athletes and soldiers. Contradiction exists among used different definitions of overuse injury. Objective: to identify most common overuse injury definition and propose overuse injury criteria based on recent literature review. Methods: literature review of the most recent literature about lower extremity overuse injuries published between 2013 and June 2018. Studies retrieved through MEDLINE, PubMEd and ScienceDirect, applying inclusion and exclusion criteria and language restrictions. Results: 18 articles met all inclusion criteria out of 2995 articles screened. Included research populations are different sport athletes (n = 11) and soldiers (n = 5). Most studies described such overuse injuries as lower extremity stress fractures (n = 10) and Achilles tendinopathy (n = 7). Most reported overuse injury definition – injury due to large amount of physical activity training (n = 8) or repetitive micro-trauma (n = 4), Conclusions: lower extremity overuse injury is an injury due to high physical load because of incomplete repair process and with gradual onset. Important criteria for defining overuse injury include absence of known single traumatic event, progressive symptoms and lack of recovery period.

The Effect of Breathing Pattern and Heel Strike Pattern on Peak Ground Reaction Force at Initial Contact During Walking

It has been proposed that during running, the greatest force occurs when the foot strikes the ground and simultaneously exhalation occurs at initial heel contact. As a result, breathing retraining has been used as a method to prevent lower extremity overuse injuries by modifying an individual's breathing pattern and consequently, reducing ground reaction forces. There is, however, little research exploring this link during walking. This study explored the interaction effect between the phase of respiration and foot strike pattern on measures of ground reaction forces while walking. The study also examined the correlation between the phase of respiration and peak forces. The research findings did not support the concept of breathing synchronization with higher ground reaction forces when exhalation occurred at heel strike during walking. The biomechanics of walking are very different than running and, therefore, the utility of breathing retraining may not be supported as has been proposed for running.

A Randomized Study of a Strength Training Program to Prevent Injuries in Runners of the New York City Marathon.

Lower extremity overuse injuries are common among runners, especially first-time marathoners. Hip abductor and quadriceps strengthening is often recommended to reduce running-related injuries. A 12-week strength training program would decrease the rate of overuse injuries resulting in marathon noncompletion and improve race finishing time. Randomized trial. Level 2. Twelve weeks before the New York City Marathon, first-time marathon runners age 18 years and older were randomized into a strength training group or an observation group. The strength training group was instructed to perform a 10-minute program 3 times weekly using written and video instruction. This program targeted the quadriceps, hip abductor, and core muscle groups. Injuries were self-reported through biweekly surveys, with major injuries being those that resulted in marathon noncompletion and minor injuries being those that impaired training or race performance. A total of 720 runners were enrolled (mean age, 35.9 ± 9.4 years; 69.4% female), of whom 583 runners started the marathon and 579 completed it. The incidence of major injury was 8.9% and minor injury was 48.5%. Fifty two of 64 major injuries were overuse, of which 20 were bone stress injuries. The incidence of overuse injury resulting in marathon noncompletion was 7.1% in the strength training group and 7.3% in the observation group (risk ratio, 0.97; 95% CI, 0.57-1.63; P = 0.90). The mean finishing time was 5 hours 1 ± 60 minutes in the strength training group and 4 hours 58 ± 55 minutes in the observation group (P = 0.35). There is a high prevalence of injury among first-time marathon runners, but this self-directed strength training program did not decrease overuse injury incidence resulting in marathon noncompletion. Prevention strategies such as strength training need to be developed and evaluated through clinical trials to reduce the high prevalence of overuse injuries in runners, especially for high-risk populations such as first-time marathon runners.

Sports Specialization Is Not Associated With Greater Odds of Previous Injury in Elite Male Youth Soccer Players.

To determine the relationship between sport specialization and previous injury in elite male youth soccer players. Retrospective survey. U.S. Soccer Development Academy. Male youth soccer players (N = 2123). Sport specialization, weekly training volume, training ratio, and age. Previous sports-related injury, injury type (traumatic vs overuse), injury severity, and injury location. Of 2099 participants (average age 13.2 ± 1.8 years), 61.7% were specialized in soccer (played soccer >8 mo/yr and no other sports) and 38.3% were nonspecialized (played soccer >8 mo/yr and also played other organized sports). Specialized athletes were older than nonspecialized athletes (13.7 ± 1.9 vs 12.5 ± 1.4, P < 0.0001). Thirty-three percent (690/2099) of athletes reported at least one previous sports-related injury for a total of 765 traumatic injuries and 25 overuse injuries. Distribution of injury type was similar for specialized and nonspecialized athletes. Among athletes with overuse injuries, nonspecialized athletes were more likely to report upper-extremity and trunk overuse injuries than specialized athletes. After accounting for age and weekly training volume, specialized athletes had decreased odds of reporting any previous injury compared with nonspecialized athletes [odds ratio (OR), 0.78; 95% confidence interval (CI), 0.64-0.95], and similar odds of reporting a previous lower-extremity (LE) overuse injury as nonspecialized athletes (OR, 0.70; 95% CI, 0.56-1.1). However, specialized athletes missed more practices due to injury than nonspecialized players [median = 3, interquartile range (IQR) 2-4 vs median = 2, IQR 2-4, P = 0.0003]. In this national sample of elite, male youth soccer players, after accounting for age and weekly training volume, specialized athletes had decreased odds of reporting any previous injury and similar odds of reporting a previous LE overuse injury as nonspecialized athletes. These data suggest the need for further research to determine whether injury risk related to sports specialization depends on sex, chosen sport, and skill/competitive level.

Impaired Core Stability as a Risk Factor for the Development of Lower Extremity Overuse Injuries: A Prospective Cohort Study

Background: Core stability has been suggested to influence lower extremity functioning and might contribute to the development of lower extremity overuse injuries. However, prospective studies to investigate this relationship are limited. Purpose: To research the role of different components of core stability as risk factors for the development of lower extremity overuse injuries. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 142 first-year physical education students participated in this study. They were tested in 2015 and were prospectively followed for 1.5 years by means of a multilevel injury registration method. Three participants were excluded owing to physical complaints during testing. As such, 139 participants were included in the statistical analysis. At baseline, dynamic postural control, isometric core and hip muscle strength, core muscle endurance, core neuromuscular control and proprioception, and functional movement were measured for all participants. Competing risk regression analyses were performed to identify significant contributors to the development of lower extremity overuse injuries. Results: During the follow-up period, 34 (24%) of the 139 participants developed a lower extremity overuse injury. Significant predictive effects for an overuse injury were found for an increased side-by-side difference in dynamic postural control (P = .038), decreased isometric hip extension:flexion strength ratio (P = .046), and decreased abdominal core muscle endurance (P = .032). Conclusion: This study identified measures for dynamic postural control, core muscle strength, and core muscle endurance as significant risk factors for the development of overuse injuries after statistical model building. However, core neuromuscular control and proprioception and functional movement might not allow clinicians to identify patients at risk. These accessible, reliable screening tools could be used in clinical practice with regard to screening and injury prevention for overuse injuries. Injury prediction based on this model needs to be done with caution given the low relative predictive accuracy (53%).

Reviewing the Variability-Overuse Injury Hypothesis: Does Movement Variability Relate to Landing Injuries?

ABSTRACTPurpose: Overuse injuries are common in sport, but complete understanding of injury risk factors remains incomplete. Although biomechanical studies frequently examine musculoskeletal injury mechanisms, human movement variability studies aim to better understand neuromotor functioning, with proposed connections between overuse injury mechanisms and changes in motor variability. Method: In a narrative review, we discuss the variability-overuse injury hypothesis, which suggests repeated load application leads to mechanical tissue breakdown and subsequent injury when exceeding the rate of physiological adaptation. Due to the multidisciplinary nature of this hypothesis, we incorporate concepts from motor control, neurophysiology, biomechanics, as well as research design and data analysis. We therefore summarize multiple perspectives while proposing theoretical relationships between movement variability and lower extremity overuse injuries. Results: Experimental data are presented and summarized from published experiments examining interactions between experimental task demands and movement variability in the context of drop landing movements, along with comparisons to previous movement variability studies. Conclusion: We provide a conceptual framework for sports medicine researchers interested in predicting and preventing sports injuries. Under performance conditions with greater task demands, we predict reduced trial-to-trial movement variability that could increase the likelihood of overuse injuries.

SPORT SPECIALIZATION IS A RISK FACTOR FOR OVERUSE, BUT NOT ACUTE, LOWER EXTREMITY INJURIES: A PROSPECTIVE STUDY

BACKGROUND: Sport specialization is often associated with intense, high volume training, which may result in injury – especially overuse injuries. However, there is limited prospective research investigating these relationships. Additionally, previous research has focused on adolescents older than 12 years of age with no data available in younger cohorts, who may be more susceptible to repetitive stress. Therefore, the purpose of this study is to determine if sport specialization is associated with increased risk of overuse and acute lower extremity injuries in middle school aged athletes. METHODS: A total of 281 children (113 females (40%), age=12.1±1.2years; range 10-14 years of age) completed an online survey with their parents for 39 weeks. The study was conducted during the 2017-2018 academic year with a baseline survey conducted the first week of September. Weekly surveys were sent to respondents via Qualtrics with the final weekly survey in June of 2018. The baseline survey consisted of 1) demographic information, 2) injury history in the previous 12 months, 3) a sport specialization scale which classified individuals in low, moderate, and high levels of specialization, and 4) sport participation volume (months per year in primary sport). The weekly surveys asked participants to report and musculoskeletal injury they sustained during sport participation. Participants were included in the analysis if they completed at least 80% of the total surveys. Multivariable logistic regression analyses were utilized to examine associations between specialization category (reference category: low) and prospective injury categories, while adjusting for differences in age, sex, and previous injury history. RESULTS: Respondents reported 57 acute and 32 overuse lower extremity injuries during the observation period. Highly specialized athletes had significantly greater odds of reporting a prospective lower extremity overuse injury than subjects in the low specialization group (OR: 3.78, 1.02-12.90, p=0.03), even after adjusting for sex, age, and previous injury history. However, specialization was not a risk factor for acute lower extremity injuries (OR: 2.20, 0.72-6.77, p=0.17). CONCLUSION: Highly specialized middle school athletes are nearly 4 times greater risk of developing an overuse injury compared to low specialization athletes. Younger athletes may be more susceptible to injuries at younger ages. Thus, adolescent athletes should avoid specialization when possible.

Surgery in Tendinopathies.

Tendinopathies are challenging. The term "tendinopathy" refers to clinical condition characterized by pain, swelling, and functional limitations of tendons and nearby structures. Tendinopathies give rise to significant morbidity, and, at present, only limited scientifically proven management modalities exist. Achilles and patellar tendons are among the most vulnerable tendons, and among the most frequent lower extremity overuse injuries. Achilles and patellar tendinopathies can be managed conservatively and surgically. Several surgical procedures have been described for both conditions, and, if performed well, they lead to a relatively higher rate of success with low complication.

Association between training volume and lower extremity overuse injuries in young female athletes: implications for early sports specialization

ABSTRACTBackground: Recent studies indicated greater risk of overuse injuries among young female athletes than their male counterparts. However, few studies have focused on female athletes and the effect of single-sport participation on lower extremity overuse injuries.Objective: The objective of this study is to identify an independent risk variable for lower extremity overuse injuries based on status of sport participations (single- and multisports) in young female athletes.Methods: In this cross-sectional study, 12–18-year-old female athletes were asked to complete electronic questionnaires describing their current sport participation and previous injury history. Range of motion (ROM), muscular strength, and performance parameters were measured at the time of completion of electronic questionnaires. Potential risk variables were compared between single- and multisport athletes and entered into a logistic regression model. Adjusted odds ratio (aOR), 95% confidence intervals (95% CIs), and p values were recorded to find an association with increased likelihood of lower extremity overuse injuries.Results: The study cohort comprised 236 female young athletes (single-sport athletes: N = 60, multisport athletes: N = 176). A few variables including age, BMI, weekly hours of training for a sport, knee ROM, ankle ROM, and knee extensor strength were identified as potential risk variables. A logistic regression analysis showed an independent association between increased weekly hours of training for a sport and greater likelihood of histories of lower extremity overuse injuries (aOR = 1.091, 95% CIs: 1.007–1.183, p = .034).Conclusion: Although status of single- or multisports participation was not a significant risk variable, increased training volume was found to be an independent contributing factor for greater likelihood of lower extremity overuse injury histories in 12–18 years female athletes. The current study identified that single-sport athletes trained nearly twice as many hours per week when compared to multisport athletes, which may explain an underlying mechanism of sports specialization.

The effect of additional activation of the plantar intrinsic foot muscles on foot kinematics in flat-footed subjects

BackgroundStrengthening exercises of the plantar intrinsic foot muscles (PIFMs) are often prescribed to flat-footed subjects because of the capacity of the PIFMs to support the medial longitudinal arch (MLA). However, it is unclear whether the capacity of the PIFMs to support the MLA is enough to change the foot kinematics in flat-footed subjects. To confirm this, the current study examined changes in foot kinematics in flat-footed subjects during standing and gait accompanied by changes in the activity of the PIFMs. MethodsEighteen flat-footed subjects were randomly assigned to an electrical stimulation group (ESG) or a control group (CG). In the ESG, electrical stimulation to the PIFMs was applied during standing and gait to simulate reinforcement of the PIFMs. Then, foot kinematics were measured using 3D motion analysis, and the amount of change from baseline (when no electrical stimulation was applied) was compared between the groups. ResultsIn the gait analysis, the time at which the MLA height reached its minimum value was significantly later in the ESG, with no reduction in the MLA height at that time. Moreover, forefoot inversion angle and tibial external rotation angle were significantly increased in the ESG at that time. In the standing analysis, there were no significant differences between the groups. ConclusionThe results revealed that in flat-footed subjects, the PIFMs have the capacity to support the MLA enough to change foot kinematics during gait. Strengthening these muscles may be effective in preventing or treating lower extremity overuse injuries related to flat-foot alignment.

Incidence and risk factors of medial tibial stress syndrome: a prospective study in Physical Education Teacher Education students

ObjectiveMedial tibial stress syndrome (MTSS) is a common lower extremity overuse injury often causing long-term reduction of sports participation. This study aimed to investigate the incidence and risk factors of...