Risk Factors For Knee Injuries Research Articles

Comparison of Knee Muscular Strength Balance among Pre- and Post-Puberty Adolescent Swimmers: A Cross-Sectional Pilot Study.

Muscular weakness and strength imbalance between the thigh muscles are considered risk factors for knee injuries. Hormonal changes, characteristic of puberty, strongly affect muscle strength; however, it is unknown whether they affect muscular strength balance. The present study aimed to compare knee flexor strength, knee extensor strength, and strength balance ratio, called the conventional ratio (CR), between prepubertal and postpubertal swimmers of both sexes. A total of 56 boys and 22 girls aged between 10 and 20 years participated in the study. Peak torque, CR, and body composition were measured using an isokinetic dynamometer and dual-energy X-ray absorptiometry, respectively. The postpubertal boys group presented significantly higher fat-free mass (p < 0.001) and lower fat mass (p = 0.001) than the prepubertal group. There were no significant differences among the female swimmers. Peak torque for both flexor and extensor muscles was significantly greater in postpubertal male (p < 0.001, both) and female swimmers (p < 0.001 and p = 0.001, respectively) than in prepubertal swimmers. The CR did not differ between the pre- and postpubertal groups. However, the mean CR values were lower than the literature recommendations, which brings attention to a higher risk of knee injuries.

Effects of pubertal growth variation on knee mechanics during walking in female and male adolescents.

Puberty substantially alters the body's mechanical properties, neuromuscular control, and sex differences therein, likely contributing to increased, sex-biased knee injury risk during adolescence. Female adolescents have higher risk for knee injuries than male adolescents of similar age engaging in similar physical activities, and much research has investigated sex differences in mechanical risk factors. However, few studies address the considerable variation in pubertal growth (timing, pace), knee mechanics, and injury susceptibility within sexes, or the impact of such growth variation on mechanical injury risk. The present study tested for effects of variation in pubertal growth on established mechanical knee injury risk factors, examining relationships between and within sexes. Pubertal growth indices describing variation in the timing and rate of pubertal growth were developed using principal component analysis and auxological data from serial stature measurements. Linear mixed models were applied to evaluate relationships between these indices and knee mechanics during walking in a sample of adolescents. Later developing female adolescents with slower pubertal growth had higher extension moments throughout stance, whereas earlier developers had higher valgus knee angles and moments. In male adolescents, faster and later growth were related to higher extension moments throughout gait. In both sexes, faster growers had higher internal rotation moments at foot-strike. Pubertal growth variation has important effects on mechanical knee injury risk in adolescence, affecting females and males differently. Earlier developing females exhibit greater injury risk via frontal plane factors, whereas later/faster developing males have elevated risk via sagittal plane mechanisms.

Positive influence of neuromuscular training on knee injury risk factors during cutting and landing tasks in elite youth female handball players

Anterior cruciate ligament (ACL) ruptures are frequent in the age group of 15–19 years, particularly for female athletes. Although injury-prevention programs effectively reduce severe knee injuries, little is known about the underlying mechanisms and changes of biomechanical risk factors. Thus, this study analyzes the effects of a neuromuscular injury-prevention program on biomechanical parameters associated with ACL injuries in elite youth female handball players. In a nonrandomized, controlled intervention study, 19 players allocated to control (n = 12) and intervention (n = 7) group were investigated for single- and double-leg landings as well as unanticipated side-cutting maneuvers before and after a 12-week study period. The lower-extremity motion of the athletes was captured using a three-dimensional motion capture system consisting of 12 infrared cameras. A lower-body marker set of 40 markers together with a rigid body model, including a forefoot, rearfoot, shank, thigh, and pelvis segment in combination with two force plates was used to determine knee joint angles, resultant external joint moments, and vertical ground reaction forces. The two groups did not differ significantly during pretesting. Only the intervention group showed significant improvements in the initial knee abduction angle during single leg landing (p = 0.038: d = 0.518), knee flexion moment during double-leg landings (p = 0.011; d = −1.086), knee abduction moment during single (p = 0.036; d = 0.585) and double-leg landing (p = 0.006; d = 0.944) and side-cutting (p = 0.015;d = 0.561) as well as vertical ground reaction force during double-leg landing (p = 0.004; d = 1.482). Control group demonstrated no significant changes in kinematics and kinetics. However, at postintervention both groups were not significantly different in any of the biomechanical outcomes except for the normalized knee flexion moment of the dominant leg during single-leg landing. This study provides first indications that the implementation of a training intervention with specific neuromuscular exercises has positive impacts on biomechanical risk factors associated with ACL injury risk and, therefore, may help prevent severe knee injuries in elite youth female handball players.

Injury History and Perceived Knee Function as Risk Factors for Knee Injury in Youth Team-Sports Athletes.

The identification of risk factors for sports injuries is essential before injury prevention strategies can be planned. Previous acute knee injury and lower perceived knee function measured by Knee injury and Osteoarthritis Outcome Score (KOOS) will increase the risk of acute knee injury in youth team-sports athletes. Prospective cohort study. Level 3. At baseline, youth (≤21 years old) male and female basketball and floorball athletes completed a questionnaire on previous acute knee injuries and perceived knee function (KOOS). A total of 211 male and 183 female athletes were followed for an acute knee injury up to 3 years. Unadjusted and adjusted Cox regression models were used in risk factor analyses. In male athletes, previous acute knee injury and lower KOOS Pain, Activities of Daily Living, Sport and Recreation, and knee-related Quality of Life subscale scores increased the risk of acute knee injury in the unadjusted analyses. Adjusted analyses for male injuries were not performed because of low number of acute knee injuries (n = 18). In female athletes, previous acute knee injury increased the risk of acute knee injury when adjusted for athletes' age and body mass index (hazard ratio, 2.6 [95% CI, 1.3-5.2]). In female athletes, none of the KOOS subscale scores were associated with the increased risk of acute knee injury in the adjusted analyses. Previous acute knee injury was associated with the risk of new acute knee injury in youth male and female athletes. In youth male athletes, additionally, lower perceived knee function in 4 out of 5 KOOS subscale scores were associated with the increased risk of new acute knee injury. The treatment and rehabilitation of the present acute knee injury and secondary prevention of reinjury should be emphasized in youth team-sports athletes.

The prevention of injuries among youth basketballers according to the “Sequence of Prevention’’: a systematic review

Background: Basketball is played by the youth worldwide, and various injuries occur in youth basketball. There is currently no overview of the incidence, the risk factors and preventive measures of musculoskeletal injuries among youth basketball players. Objective: This systematic review describes the most common injuries among youth basketball players. The most common risk factors and various preventive measures and interventions have also been reported and discussed. Methods: Search strategies were built based on groups of keywords, namely ‘injury’, ‘youth basketball’, and ‘cohort’. Search strategies were entered into Medline and SPORTDiscus. Titles, abstracts and full text articles were screened by two researchers. Data from the included articles were extracted by one researcher and checked by another researcher. Results: Twenty-seven studies showed that the overall injury rate ranged from 2.64 to 3.83 per 1 000 hours of exposure. Ankle- (22%-37%) and knee injuries (5%-41%) were the most common injuries. Risk factors for knee injuries included ankle dorsiflexion with a range less than 36.5 degrees and female athletes with greater hip abduction strength. High variations of postural sway corresponded to occurrences of ankle injuries (p=0.01, OR =1.22; p&lt;0.001, OR =1.22). A core intervention (rate = 4.99/1 000 athlete exposure (AEs)) focused on the trunk and lower extremity led to a reduction in injuries compared to a sham intervention (rate =7.72/1 000 AEs) (p=0.02). Wearing a McDavid Ultralight 195 brace reduced ankle injuries compared to the controls (HR 0.30; 95 % CI 0.17 0.90; p=0.03). Conclusion: Ankle and knee injuries are the most common injuries among youth basketball players. Poor postural control, reduced ankle dorsiflexion and high hip abduction strength are the main risk factors. A neuromuscular warm-up, in combination with strength and stability exercises, seems to be the best training method to prevent injuries. Ankle injuries can be reduced by wearing a lace-up ankle brace.

Prediction of the Risk Factors of Knee Injury During Drop-Jump Landing With Core-related Measurements in Amature Basketball Players.

Purpose: To evaluate the relationship between specific aspects of core stability and knee injury risk factors during drop-jump (DJ) landing.Methods: Eighteen college-aged male amateur basketball players participated in the project. Kinetic and kinematic data for DJ tasks were collected with force plates and infrared cameras. Raw data were processed to calculate knee joint angles and joint moments during DJ landing. Different components of core stability were represented by the sit-ups in 20 s (SU), trunk extensor endurance, trunk flexion and extension range of motion, dominant extremity single-leg stance time (DLS), and dominant extremity single-leg hop distance, respectively.Methods: Correlation and regression were used to determine the relationship between jumping-related biomechanical parameters and core stability components.Results: SU shared significant variance with the peak moment of knee extension (PMKE, p < 0.05), the peak moment of knee abduction (PMKA, p < 0.05), and the angle of knee internal rotation at initial contact (AKRI, p < 0.05). DLS shared significant variance with the angular motion of knee internal rotation (AMKR, p < 0.05) and the AKRI (p < 0.01). SU and DLS together could explain 52% of the variance observed in the AKRI, and the result was significant.Conclusion: Core stability’s strength and motor control aspects played an essential role in preventing knee injury during DJ landing. An integrative training program addressing core strength and motor control could be considered for coaches and athletes to prevent knee injury through core training and conditioning.

Change of Direction Biomechanics in a 180-Degree Pivot Turn and the Risk for Noncontact Knee Injuries in Youth Basketball and Floorball Players

Background: Studies investigating biomechanical risk factors for knee injuries in sport-specific tasks are needed. Purpose: To investigate the association between change of direction (COD) biomechanics in a 180-degree pivot turn and knee injury risk among youth team sport players. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 258 female and male basketball and floorball players (age range, 12-21 years) participated in the baseline COD test and follow-up. Complete data were obtained from 489 player-legs. Injuries, practice, and game exposure were registered for 12 months. The COD test consisted of a quick ball pass before and after a high-speed 180-degree pivot turn on the force plates. The following variables were analyzed: peak vertical ground-reaction force (N/kg); peak trunk lateral flexion angle (degree); peak knee flexion angle (degree); peak knee valgus angle (degree); peak knee flexion moment (N·m/kg); peak knee abduction moment (N·m/kg); and peak knee internal and external rotation moments (N·m/kg). Legs were analyzed separately and the mean of 3 trials was used in the analysis. Main outcome measure was a new acute noncontact knee injury. Results: A total of 18 new noncontact knee injuries were registered (0.3 injuries/1000 hours of exposure). Female players sustained 14 knee injuries and male players 4. A higher rate of knee injuries was observed in female players compared with male players (incidence rate ratio, 6.2; 95% CI, 2.1-21.7). Of all knee injuries, 8 were anterior cruciate ligament (ACL) injuries, all in female players. Female players displayed significantly larger peak knee valgus angles compared with male players (mean for female and male players, respectively: 13.9°± 9.4° and 2.0°± 8.5°). No significant associations between biomechanical variables and knee injury risk were found. Conclusion: Female players were at increased risk of knee and ACL injury compared with male players. Female players performed the 180-degree pivot turn with significantly larger knee valgus compared with male players. However, none of the investigated variables was associated with knee injury risk in youth basketball and floorball players.

Isokinetic Muscular Strength and Aerobic Physical Fitness in Recreational Long-Distance Runners: A Cross-Sectional Study.

Andrade, MS, Silva, WA, de Lira, CAB, Mascarin, NC, Vancini, RL, Nikolaidis, PT, and Knechtle, B. Isokinetic muscular strength and aerobic physical fitness in recreational long-distance runners: A cross-sectional study. J Strength Cond Res 36(3): e73-e80, 2022-Muscular strength, bilateral asymmetry, and imbalance between antagonist muscles have been considered as risk factors for knee injuries. Moreover, muscular strength has also been associated with aerobic performance. The aim of the study was to investigate bilateral muscular symmetry and muscular strength balance assessed by isokinetic dynamometry in recreational long-distance runners and to verify whether knee muscular strength would be associated with maximal oxygen uptake (V̇o2max), anaerobic threshold (AT), and running economy (RE). Thirty-nine runners (male [n = 24]: age, 30 ± 8 years; height, 176.0 ± 7.3 cm; body mass, 70.3 ± 8.0 kg; race pace below 4:30 min·km-1 and female [n = 15]: age, 31 ± 7 years; height, 163.0 ± 3.8 cm; body mass, 55.9 ± 4.7 kg; race pace below 5:00 min·km-1) participated in this study. Comparing the conventional knee balance ratio with the literature recommendation (60%), male runners presented significantly lower values for the nondominant side (55.5 ± 7.3%; p = 0.001; d = 0.85; confidence interval [CI] = 0.47 to 1.20) but not for the dominant side (58.1 ± 6.8%; p = 0.208; d = 0.37; CI = -0.12 to 0.86). Female runners presented lower values for both sides (52.1 ± 7.1%; p = 0.001; d = 1.55; CI = 0.86 to 2.20 and 50.7 ± 8.0%; p = 0.001; d = 1.62; CI = 0.90 to 2.30 for dominant and nondominant sides, respectively). Female and male runners presented nonfunctional ratio imbalance and asymmetry of bilateral strength. Strength outcomes were not associated with V̇o2max, AT, or RE. In conclusion, recreational runners were characterized by an imbalance in muscular strength between knee flexor and extensor muscles, which was more obvious in female runners, and by symmetrical thigh muscle strength values. Moreover, muscular isokinetic knee flexor and extensor muscle strength was not associated with aerobic fitness parameters.

The Influence of Asymptomatic Hypermobility on Unanticipated Cutting Biomechanics.

Generalized joint hypermobility is an important risk factor for knee injuries, including to the anterior cruciate ligament (ACL). Examining movement patterns specific to hypermobile individuals during sport-specific movements could facilitate development of targeted recommendations and injury prevention programs for this population. Asymptomatic hypermobile participants will present kinematics measures suggestive of a greater risk of noncontact knee or ACL injuries. Cross-sectional study. Level 3. Forty-two (15 asymptomatic hypermobile and 27 nonhypermobile) individuals performed unanticipated side-step cutting on their dominant and nondominant legs. Ankle, knee, hip, pelvis, and trunk angles in all planes of motion were collected during the first 100 ms after initial contact using a 3-dimensional infrared system. Precontact foot-ground angles were also extracted. Data from hypermobile and nonhypermobile groups were compared using multiple regression models with sex as a confounder. When nonsignificant, the confounder was removed from the model. Effect sizes (Hedge g) were calculated in the presence of significant between-group differences. Hypermobile individuals presented with lower minimum knee valgus angles with a mean difference of 3.5° (P = 0.03, Hedge g = 0.69) and greater peak knee external rotation angles with a mean difference of -4.5° (P = 0.04, Hedge g = 0.70) during dominant leg cutting, and lower peak ankle plantarflexion angles with a mean difference of 4.5° (P = 0.03, Hedge g = 0.73) during nondominant leg cutting compared with nonhypermobile individuals. Based on current scientific evidence, however, the identified differences are not crucial biomechanical injury risk factors that could predispose asymptomatic hypermobile individuals to noncontact knee or ACL injuries. Further research is needed to highlight differences between hypermobility groups. Knowledge of the differences between these groups may change the physical activity recommendations, prevention of injury, and rehabilitation approaches.

Role of activation patterns of hip muscles in single-leg squats in healthy patients

Introduction:A risk factor for knee injuries is the medio-lateral displacement of the knee joint during a single-leg squat (SLS). It is to be supposed that different activation patterns of hip muscles are related to the medio-lateral displacement of the knee (1). Yet, little is known about the electromyographic (EMG) ratio between gluteus medius (GM) and the adductor muscles (ADD) at different knee flexion angles (2). Therefore, the EMG ratio between GM and ADD at different knee flexion angles was assessed during the SLS. These data should build a normative data base of healthy controls for getting in-sights on knee injury prevention.Hypotheses:The hypothesis was that according to different knee flexion angles, there is a variabil-ity of the EMG ratio between GM and ADD in healthy patients.Methods:A total of 17 healthy subjects (9 female/ 8 male, age of 25±4 years, BMI of 24±2 kg/m2) were included into the study. Exclusion criteria were Genu varum or Genu val-gum and pathologies which might affect coordination abilities of the lower extremities. Knee flexion angle was captured with a 3D motion analysis system (Vicon Motion Systems, Oxford,UK). Muscle activity of GM and ADD was measured by surface electromyography (Myon AG Schwarzener, CH). The EMG signal (10-500Hz band-pass filter, rectified, 250ms moving average) was normalized to maximum EMG am-plitude during a static maximum voluntary contraction against a handheld dynamome-ter (MicroFET2, Hoggan Scientific, UT, USA). The EMG ratio was defined as muscle activity of GM [%max] divided by muscle activity of ADD [%max]. Every participant did 12 single-leg squats on each side.Results:EMG ratio (median, interquartile range (25th - 75th quartile)) was calculated at the fol-lowing knee flexion angles (mean ± SD): EMG ratio at start position (11°±6°) = 2.5 (1.9 – 4.2), EMG ratio at 40° downward movement = 1.5 (1.1 – 2.7), EMG ratio at 60° downward movement = 1.2 (0.9 – 2.2), EMG ratio at maximum flexion angle (86°±16°) = 1.3 (0.9 – 1.9), EMG ratio at 60° upward movement = 2.0 (1.2 – 3.3), EMG ratio at 40° upward movement = 2.3 (1.5 – 4.4), EMG ratio at end position (8°±6°) = 3.2 (2.3 – 5.4).Conclusion:In the literature, the mean EMG ratios between GM and ADD at maximum knee flex-ion were ranged from 1.3 to 1.9 in healthy patients (3,4) and are comparable to our findings. The knee and hip have to be more stabilized during the upward movement by higher EMG ratios. The lower EMG ratio in the downward phase might be associated, amongst others, with the eccentrical deceleration movement. We assume that the consistently higher activation of the GM is attributed to its function as an essential hip stabilizer as well as to avoid a collapse in the knee joint in every single-leg situation. Therefore, we recommend hip abductor focused training to prevent knee injuries. Our results provide a basis for the comparison with patients and for the interpretation of medio-lateral displacements of the knee joint during a SLS.

Limited Support for Trunk and Hip Deficits as Risk Factors for Athletic Knee Injuries: A Systematic Review With Meta-analysis and Best-Evidence Synthesis.

To determine whether neuromuscular deficits in trunk and hip-related function are risk factors for athletic knee injuries. Etiology systematic review with meta-analysis. Six online databases (MEDLINE, Web of Science, Embase, CINAHL, Scopus, and SPORTDiscus) were searched up to April 2019. Studies assessing trunk and hip neuromuscular function as risk factors for knee injuries in healthy athletic populations were included. Outcomes were synthesized quantitatively using meta-analysis of odds ratios, and qualitatively using best-evidence synthesis. Twenty-one studies met the inclusion criteria. There was very low-certainty evidence that greater hip external rotation strength protected against knee injuries (odds ratio = 0.78; 95% confidence interval: 0.70, 0.87; P<.05). There was limited evidence that deficits in trunk proprioception and neuromuscular control, and the combination of excessive knee valgus and ipsilateral trunk angle when landing unilaterally from a jump, may be risk factors for knee injuries. Most variables of trunk and hip function were not risk factors for injuries. Further research is required to confirm whether hip external rotation strength, trunk proprioception and neuromuscular control, and the combination of knee valgus angle and ipsilateral trunk control are risk factors for future knee injuries. J Orthop Sports Phys Ther 2020;50(9):476-489. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9705.

The association between genu recurvatum angle and the strength of the hip and knee muscles in standing workers.

Increased genu recurvatum (GR) angle is a risk factor for knee injury. Identification of factors causing GR is important for the prevention and rehabilitation of GR. Few studies have investigated the association between muscle strength and GR. To examine the association between GR angle and hip and knee muscle strength in standing workersMETHODS:The participants in this study were 110 healthy volunteers (59 male, 51 female) who performed standing work in a theme park. The GR angle, muscle strength, and strength ratio of the lower extremities were measured to determine their associations with GR. The GR angle was measured using a Smart KEMA motion sensor, and muscle strength was assessed using a Smart KEMA strength sensor. Stepwise multiple regression models were used to investigate which muscles contributed most to the extent of the GR angle. Stepwise multiple regression analysis showed that the decreased hip external rotator to hip internal rotator ratio, increased knee extensor to knee flexor ratio, and young age were associated with an increased GR angle. Many factors are known to increase the GR angle. However, this study investigated the roles of only hip and knee muscle strength. The results suggest that muscle strength ratios are more important than the weakness of any muscle.

Which Risk Factors Predict Knee Ligament Injuries in Severely Injured Patients?-Results from an International Multicenter Analysis.

Introduction: Ligament injuries around the knee joint and knee dislocations are rare but potentially complex injuries associated with high-energy trauma. Concomitant neurovascular injuries further affect their long-term clinical outcomes. In contrast to isolated ligamentous knee injuries, epidemiologic data and knowledge on predicting knee injuries in severely injured patients is still limited. Methods: The TraumaRegister DGU® (TR-DGU) was queried (01/2009–12/2016). Inclusion criteria for selection from the database: maximum abbreviated injury severity ≥ 3 points (MAIS 3+). Participating countries: Germany, Austria, and Switzerland. The two main groups included a “control” and a “knee injury” group. The injury severity score (ISS) and new ISS (NISS) were used for injury severity classification, and the abbreviated injury scale (AIS) was used to classify the severity of the knee injury. Logistic regression analysis was performed to evaluate various risk factors for knee injuries. Results: The study cohort included 139,462 severely injured trauma patients. We identified 4411 individuals (3.2%) with a ligament injury around the knee joint (“knee injury” group) and 1153 patients with a knee dislocation (0.8%). The risk for associated injuries of the peroneal nerve and popliteal artery were significantly increased in dislocated knees when compared to controls (peroneal nerve from 0.4% to 6.7%, popliteal artery from 0.3% to 6.9%, respectively). Among the predictors for knee injuries were specific mechanisms of injury: e.g., pedestrian struck (Odds ratio [OR] 3.2, 95% confidence interval [CI]: 2.69–3.74 p ≤ 0.001), motorcycle (OR 3.0, 95% CI: 2.58–3.48, p ≤ 0.001), and motor vehicle accidents (OR 2.2, 95% CI: 1.86–2.51, p ≤ 0.001) and associated skeletal injuries, e.g., patella (OR 2.3, 95% CI: 1.99–2.62, p ≤ 0.001), tibia (OR 1.9, 95% CI: 1.75–2.05, p ≤ 0.001), and femur (OR 1.8, 95% CI: 1.64–1.89, p ≤ 0.001), but neither male sex nor general injury severity (ISS). Conclusion: Ligament injuries and knee dislocations are associated with high-risk mechanisms and concomitant skeletal injuries of the lower extremity, but are not predicted by general injury severity or sex. Despite comparable ISS, knee injuries prolong the hospital length of stay. Delayed or missed diagnosis of knee injuries can be prevented by comprehensive clinical evaluation after fracture fixation and a high index of suspicion is advised, especially in the presence of the above mentioned risk factors.

Altered hip control during a standing knee-lift test is associated with increased risk of knee injuries.

A few prospective studies have investigated hip and pelvic control as a risk factor for lower extremity (LE) injuries. The purpose of this study was to investigate whether deficits in hip and lumbopelvic control during standing knee-lift test are associated with increased risk of acute knee and LE injuries in youth team sports. At baseline, 258 basketball and floorball players (aged 12-21years) participated in a standing knee-lift test using 3-dimensional motion analysis. Two trials per leg were recorded from each participant. Peak sagittal plane pelvic tilt and frontal plane pelvic drop/hike were measured. Both continuous and categorical variables were analyzed. New non-contact LE injuries, and match and training exposure, were recorded for 12months. Seventy acute LE injuries were registered. Of these, 17 were knee injuries (eight ACL ruptures) and 35 ankle injuries. Risk factor analyses showed that increased contralateral pelvic hike was significantly associated with knee injury risk when using categorical variable (HR for high vs low group 4.07; 95% CI 1.32-12.6). Furthermore, significant association was found between high lateral pelvic hike angles and ACL injury risk in female players (HR for high vs low group 9.10; 95% CI 1.10-75.2). Poor combined sensitivity and specificity of the test was observed. In conclusion, increased contralateral pelvic hike is associated with non-contact knee injury risk among young team sport players and non-contact ACL injuries among female players. More research to determine the role of pelvic control as a risk factor for knee injuries is needed.

Assessing work-related risk factors for musculoskeletal knee disorders in construction roofing tasks

Roofers often suffer from musculoskeletal disorders (MSDs) to their knees due to spending a large amount of time kneeling while performing work-related roofing activities on sloped rooftops. Several ergonomic studies have identified kneeling as a potential risk factor for knee injuries and disorders. Existing biomechanical models and sensor technologies used to assess work-related risk factors for different construction trades are not applicable in roof work settings especially on slanted rooftop surfaces. This work assesses the impacts of work-related factors, namely working posture and roof slope, on the potential risk of developing knee MSDs due to residential roofing tasks in a laboratory setting. Nine human subjects participated in the experiment and mimicked shingle installation on a slope-configurable wooden platform. Maximum angles of right and left knee flexion, abduction, adduction, and axial rotation (internal and external) were measured as risk indicators using a motion capture system under different roof slope settings. The results demonstrated that roof slope, working posture and their interaction may have significant impacts on developing knee MSDs during roofing activities. Knees are likely to be exposed to increased risk of MSDs due to working in a dynamic kneeling posture during shingle installation. In our study, flexion in both knees and adduction in the right knee were found lower in high-pitched rooftops; however, abduction in the left knee and internal rotation in the right knee were found higher during shingle installation. Hence proper attention is needed for these situations. This study provides useful information about the impact of roof work settings on knee MSDs development, which may facilitate effective interventions such as education, training, and tools to prevent knee injuries in construction roofing tasks.

Changes in biomechanical knee injury risk factors across two collegiate soccer seasons using the 11+ prevention program.

The 11+ injury prevention program effectively reduces injuries in high school-aged female soccer player, but the mechanism of the 11+ is unknown, particularly whether it impacts biomechanical risk factors associated with knee injuries. The purpose of this study was to report the changes in hip and knee biomechanics with use of the 11+ over two soccer seasons. Two collegiate women's soccer teams performed the 11+ for two soccer seasons. A control team was followed for one season. Athletes performed motion analysis of a drop vertical jump during preseason and postseason. Both groups had meaningful increases in peak knee abduction angle over the first season, and there were no meaningful changes in peak knee abduction moment over either season. The control group had bilateral decreases in knee flexion angle. The program did not seem to systematically impact biomechanical risk factors associated with knee injuries, with increases in peak knee abduction angle and no bilateral changes in frontal or transverse hip motion. The 11+ may have mitigated clinically meaningful decreases in knee flexion; however, as ACL injuries do not occur purely in the sagittal plane, it is unclear the impact of these changes. The results of this study indicate that the 11+ may require some modifications to impact landing biomechanics and potentially risky movement patterns, particularly when used in collegiate women over multiple seasons.

Incidence and risk factors of knee injuries associated with ipsilateral femoral shaft fractures: A multicentre retrospective analysis of 429 femoral shaft injuries

A femoral shaft fracture is usually a high-energy injury and, thus, is likely to be accompanied by an injury of adjacent joints such as a knee ligament injury. However, these associated injuries are often neglected because of severe pain and deformity. The purpose of the current study is to evaluate the incidence, type and risk factors of ipsilateral knee injuries associated with femoral shaft fractures.A total of 429 femoral shaft fractures were included in this study from January 2010 to September 2015. There were 320 males and 109 females, with mean age of 40.7 years (range, 15–88). Exclusion criteria were skeletally immature patients and patients with metabolic bone disease such as osteoporosis, atypical femoral fractures, and pathologic fractures. The incidence and type of knee injury were identified, and the injury mechanisms, AO/OTA classification of the femoral shaft fractures, were analysed for assessment of risk factors for knee injuries combined with femoral shaft fractures.Knee injuries were found in 131 cases. Knee ligament injuries were identified in 87 cases. There were 20 posterior cruciate ligament injuries, 11 anterior cruciate ligament (ACL) injuries, 16 medial collateral ligament (MCL) injuries, 8 lateral collateral ligament (LCL) injuries, and 32 multi-ligament injuries. In 24 cases, ligament injuries were not detected before internal fixation of femoral shaft fractures. Average time of diagnosis for ligament injury after fixation in these neglected cases was about 10.6 weeks (range, 1–32).Fractures around the knee joint were identified in 69 cases; there were 32 patellar fractures, 14 distal femoral intra-articular fractures, 14 tibia plateau fractures, 3 proximal fibular fractures, and 6 combined fractures.Male sex, type C fracture of AO/OTA classification, and motor vehicle accidents were identified as risk factors for associated ipsilateral knee injuries in femoral shaft fractures.Knee injuries were identified in approximately 30% of femoral shaft fractures. About 30% of ligament injuries were not detected before internal fixation of femoral shaft fractures. Care should be taken since knee injuries can be accompanied by ipsilateral femoral shaft fractures.

Prevention of knee injuries and ACL ruptures Systematic review and recommendations of the the German Knee Society (DKG): The Stop-X program

Aims and Objectives: Introduction Knee injuries and especially anterior cruciate ligament (ACL) tears are frequent in athletes. Therefore, primary and secondary prevention of sports-related lower limb injuries is an ongoing topic of interest. The aim of present study was to establish guidelines for the prevention of knee and ACL injuries on the basis of evidence-based concepts represented in current literature. Methods: A comprehensive literature review regarding prevention programs for knee and ACL injuries was conducted. Results: Several modifiable and non-modifiable risk factors for knee injuries in athletes have been reported in literature. Referring to the ACL, specific injury mechanisms have been identified and are well understood. In particular, it has been demonstrated that dynamic valgus is one of the most important modifiable risk factors. Simple tests like the drop jump test have shown their efficacy in screening and detecting athletes at risk. There is only little evidence for the preventive effect on knee and ACL injuries by single exercises. However, in order to prevent or correct endangering movement patterns including dynamic valgus, several complex prevention programs have been developed in the past. These prevention programs are included in standard warm-up exercises and are focusing on muscle strength, balance, and proprioception, as well as running and flexibility. It is reported that these training programs can reduce the incidence of knee injuries by up to 27% and ACL injuries by up to 51%. Conclusions Screening, identification, and correction of endangering movement patterns like the dynamic valgus are the first crucial steps in order to prevent knee and ACL injuries in athletes. Furthermore, jumping, running and flexibility exercises as well as balance and strength training are proven to reduce the incidence of these injuries and should, therefore, be integrated into the regular warm up program. Appropriate complete prevention programs are freely accessible via the Internet and should be adapted to the specific sport disciplines

Evidence-based concepts for prevention of knee and ACL injuries. 2017 guidelines of the ligament committee of the German Knee Society (DKG).

Knee injuries and especially anterior cruciate ligament (ACL) tears are frequent in athletes. Therefore, primary and secondary prevention of sports-related lower limb injuries is an ongoing topic of interest. The aim of present study was to establish guidelines for the prevention of knee and ACL injuries on the basis of evidence-based concepts represented in current literature. A comprehensive literature review regarding prevention programs for knee and ACL injuries was conducted. Several modifiable and non-modifiable risk factors for knee injuries in athletes have been reported in literature. Referring to the ACL, specific injury mechanisms have been identified and are well understood. In particular, it has been demonstrated that dynamic valgus is one of the most important modifiable risk factors. Simple tests like the drop jump test have shown their efficacy in screening and detecting athletes at risk. There is only few evidence for the preventive effect on knee and ACL injuries by single exercises. However, in order to prevent or correct endangering movement patterns including dynamic valgus, several complex prevention programs have been developed in the past. These prevention programs are included in standard warm-up exercises and are focusing on muscle strength, balance, and proprioception, as well as running and flexibility. It is reported that these training programs can reduce the incidence of knee injuries by up to 27% and ACL injuries by up to 51%. Screening, identification, and correction of endangering movement patterns like the dynamic valgus are the first crucial steps in order to prevent knee and ACL injuries in athletes. Furthermore, jumping, running and flexibility exercises as well as balance and strength training are proven to reduce the incidence of these injuries and should, therefore, be integrated into the regular warm up program. Appropriate complete prevention programs are freely accessible via the Internet and should be adapted to the specific sport disciplines.

Eccentric Exercise, Kinesiology Tape, and Balance in Healthy Men.

Deficits in balance have been identified as a possible risk factor for knee injuries in athletes. Despite a lack of evidence for its effectiveness, kinesiology tape (KT) is widely used to prevent knee injuries. To investigate the influence of KT at the knee joint on balance ability in healthy men after eccentric exercise. Crossover study. University laboratory. Twelve young men with no history of lower limb injury volunteered for the study (age = 23.3 ± 2.6 years). All participants were students enrolled in a sports science program. Participants performed the balance test with and without KT at the knee joint on 2 separate days. The ability to maintain balance was assessed during a single-legged-stance test using a computerized balance-stability test system. The test was performed before and after 30 minutes of downhill walking on a treadmill. Eccentric exercise resulted in a deterioration of balance ability, which was attenuated by the use of KT. Further analyses revealed that the effectiveness of KT depended on the participant's balance status, with the preventive effect being greater in participants presenting with poorer baseline balance ability. Applied to the knee joint, KT counteracted the exercise-related deterioration of balance ability observed when no tape was used. Participants presenting with below-average balance ability received more benefit from KT. By preventing exercise-related impairment of balance ability, KT might help to reduce the risk of sport-associated knee injuries.