Frontal Plane Projection Angle Research Articles

Reliability of the Frontal Plane Knee Alignment Measurement Based on a Remote Protocol.

The analysis of movement quality is important for better exercise prescription. This study tested the reproducibility of a protocol for remote assessment of dynamic knee alignment using images taken by patients. Thirteen women filmed themselves performing single-leg squats on two days at a 15-day interval. Three raters measured the knee frontal plane projection angle using the resultant images. Two participants (15.4%) were excluded for not performing the protocol correctly. The intraclass correlation coefficient was between 0.880 and 0.999 for the intra-rater comparison, and between 0.817 and 0.987 for the inter-rater comparison. The success of the protocol in 84.6% of participants and the excellent reproducibility suggest that the methodology of analyzing patient-captured cell phone images might be a plausible alternative for remote evaluation of dynamic knee alignment.

Frontal plane projection angle predicts patellofemoral pain: Prospective study in male military cadets

BackgroundPatellofemoral pain (PFP) is a major source of knee pain. Identifying who may develop PFP is of paramount importance. PurposeTo assess whether Frontal plane projection angles (FPPA) and hand held dynamometry (HHD) strength measures can predict development of PFP. Study designProspective evaluation of individuals undertaking a military training programme. MethodsMale military recruits were enrolled and prospectively followed up from enrolment to completion of 12-weeks training. Lower limb kinematics (FPPA, Q-angle, hip adduction angle, knee flexion, ankle dorsiflexion, and rearfoot eversion angle) measured during running, single leg squatting (SLS), and single leg landing (SLL) and isometric muscle strength of hip abductors and knee extensors. ResultsBody mass, hip abductor muscle strength, Q-angle during SLS and SLL, FPPA during SLL all significantly different between the PFP and non-injured groups and predicted PFP, highest predictor variable was FPPA during SLL (Odds Ratio = 1.13, P = 0.01). A FPPA≥5.2° during SLL predicting PFP with a sensitivity of 70% and a specificity of 70%. ConclusionParticipants who developed PFP had a number of physical factors significantly different than the non-injured group, most predictive was a larger FPPA during SLL, with angles greater than 5.2° associated with a 2.2x greater risk. Clinical relevanceAssessing FPPA during SLL could be used to determine who was predisposed to PFP.

Does the 2D Frontal Plane Projection Angle Predict Frontal Plane Knee Moments during Stepping, Landing, and Change of Direction Tasks?

Although dynamic knee valgus can be visually identified using the 2D frontal plane projection angle (FPPA), the validity of the FPPA in terms of predicting frontal plane knee kinematics has been questioned. The biomechanical utility of the FPPA may lie in its ability to predict frontal plane knee moments. The purpose of the current study was to comprehensively evaluate the ability of the FPPA to predict the frontal plane knee kinetics (peak moment, average moment, and moment at peak knee flexion) across a wide range of tasks (stepping, landing, and change of direction). Crossover Study Design. Three-dimensional lower-extremity kinetics and 2D video were obtained from 39 healthy athletes (15 males and 24 females) during execution of six tasks (step down, drop jump, lateral shuffle, deceleration, triple hop, side-step-cut). Linear regression analysis was performed to determine if the 2D FPPA at peak knee flexion predicted frontal plane knee moment variables during the deceleration phase of each task (peak moment, average moment, moment at peak knee flexion). The FPPA was found to significantly predict the peak frontal plane knee moment for two tasks (deceleration and side-step-cut, R2 = 12% to 25%), average frontal plane knee moment for five tasks (drop jump, shuffle, deceleration, triple hop, side-step-cut, R2 = 15% to 40%), and frontal plane knee moment at peak knee flexion for five tasks (drop jump, shuffle, deceleration, triple hop, side-step-cut, R2 = 16% to 45%). An increased FPPA (medial knee collapse) predicted increased knee valgus moments (or decreased knee varus moments) during landing and change of direction tasks (but not stepping). However, the predictive ability of the FPPA was weak to moderate.

Are proximal and distal neuromuscular parameters able to predict hip and knee frontal plane kinematics during single-leg landing?

ObjectiveTo determine if proximal and distal neuromuscular parameters (EMG amplitude and median frequency – MDF) can predict frontal plane kinematics during single-leg landing. Study designCross sectional study. SettingLaboratory. ParticipantsFifteen participants (7 female) performed six single-leg landings with measures of frontal plane kinematics and EMG obtained 230 ms after first foot contact, totalizing 90 landings. Main outcome measures(i) 2D hip adduction [hip ADD] and knee frontal plane projection angle [knee FPPA]; (ii) EMG amplitude and MDF of gluteus medius [GMed], tensor fascia latae [TFL], peroneus longus [PL] and tibialis anterior [TA]. ResultsWe observed that MDF of TA was a significant predictor of hip ADD (p = 0.037; β = −0.049 Hz; R2c = 0.30). Also, MDF of PL was significant predictor of knee FPPA (p = 0.043; β = 0.042 Hz; R2c = 0.37). Hip muscles and EMG amplitude parameters were not considered predictors of frontal plane kinematics. ConclusionThe firing frequency of ankle muscles predicted the variance of hip and knee frontal plane kinematics during single-leg landing.

Reliability and criterion validity of two-dimensional movement assessments in those with patellofemoral pain

ObjectivesDetermine criterion validity and intra/inter-rater reliability of 2-dimensional (2D) knee frontal plane projection angle (kFPPA), hip frontal plane projection angle (hFPPA), and dynamic valgus index (DVI) during forward step-downs in those with patellofemoral pain (PFP). DesignCross-sectional. SettingUniversity research laboratory. Participants39 participants with PFP (34.18 ± 7.41years, 170± .1 cm, 81.03 ± 19.36 kg, duration of pain: 68.67 ± 85.08months, anterior knee pain scale: 80.49 ± 7.87, visual analog scale:2.08 ± 2.02) Main outcome measuresAverage 3D hip and knee sagittal, frontal, and transverse joint angles and 2D kFPPA, hFPPA, and DVI at maximum knee flexion were variables of interest. 3D DVI was calculated as the sum of hip and knee frontal and transverse angles. 2D kFPPA, hFPPA, and DVI were calculated by two raters independently on two occasions. ResultsIntra- and inter-rater reliability of all 2D angles were excellent. kFPPA was moderately correlated to 3D knee transverse angles. hFPPA was moderately correlated to 3D hip frontal and transverse angles and largely correlated to 3D DVI. 2D DVI was moderately correlated to hip transverse angles. ConclusionkFPPA, hFPPA, and DVI are reliable. hFPPA may be reflective of 3D hip and knee frontal and transverse motion during forward step-downs in those with PFP.

Is spinopelvic sagittal alignment correlated with pain level, functional disability and frontal plane projection angle in women with patellofemoral pain syndrome? A cross-sectional study

There is a growing interest concerning the understanding of measurements of spinal and leg alignment in patients with patellofemoral pain syndrome (PFPS). However, evaluating spinopelvic alignment in the sagittal plane with pain level, functional disability and frontal plane projection angle (FPPA) in PFPS has not been adequately addressed. The aim of the study was to identify the correlation of spinopelvic parameters with pain level, functional disability and frontal plane projection angle in women with PFPS. This was a cross–sectional study involving sixty female patients diagnosed with PEPS, with a mean age of 32±6.47. The measurements used in the study included: radiographic parameters (X-Ray), the numeric pain rating scale (NPRS), the Arabic anterior knee pain scale (AAKP/Kujala) and the 2D-FPPA. Spearman correlation analysis was conducted to evaluate the relationship between these parameters. The results of our study demonstrated a strong positive correlation of lumbar lordosis (LL) with pain level and FPPA (r=0.825, r=0.812, p=0.0001). Also, a strong positive correlation of sacral slope (SS) with pain level (r = 0.0.820) and FPPA (r= 0.783). Pelvic tilt (PT) showed a moderate correlation with pain level (r = 0.0.614) and FPPA (r= 0.605), while a weak negative correlation was found between LL, SS and PT and functional disability score (r=-0.397, r=-0.385 and, r=-0.215 p=0.002). It was concluded that LL, SS and PT were significantly related to the pain level, functional disability and frontal plane projection angle in women with PFPS. These spinal alignments should be considered in clinical evaluation of knee-related disorders associated with PFPS.

The relationship between ankle dorsiflexion range of motion, frontal plane projection angle, and patellofemoral pain syndrome

BackgroundAnkle range of motion abnormalities have been often linked with alteration in knee kinematics leading to the development of patellofemoral pain syndrome (PFPS). Literature exploring the relationship between ankle dorsiflexion range of motion (DF ROM) and knee kinematics during functional tasks is scanty. This study aims to assess the relation between ankle DF ROM and frontal plane projection angle (FPPA), one of the knee kinematic variables, in individuals with and without PFPS during a step-down test. MethodsThis is a case-control study in which seventy PFPS patients and other 70 asymptomatic control subjects had their ankle DF ROM measured using an inclinometer with the knee flexed and extended. Their FPPA angles were measured using Kinovea software while doing the step-down test. ResultsWhen the two groups were compared, ankle DF ROM measured with the knee flexed was higher in the control group (33.15 ± 4.96) than in the PFPS group (30.20 ± 6.93) (p = 0.03). In both the PFPS group and the control group, the correlation between FPPA and ankle DF ROM with the knee flexed was statistically insignificant (p = 0.075 and 0.323 respectively). ConclusionDecreased ankle DF ROM can be one of the contributing factors to the development of PFPS in the context of greater dynamic knee valgus.

Criterion Validity and Reliability of Knee Frontal Plane Projection Angles Measured Using the Technique Application.

Abnormal knee frontal plane projection angles (FPPA) during movement have been associated with patellofemoral pain. As such, clinicians are interested in valid and reliable instruments suitable for broad-based clinical use that allow them to objectively measure such variables. Therefore, the purpose of the current study was to examine the criterion validity and reliability of knee FPPA measures obtained by clinicians using a free tablet application called Technique. Validity/reliability study. To examine validity, the same raters measured 10, two-dimensional criterion reference angles at the first testing session. To examine reliability, the knee FPPA of 16 subjects was measured by 6 raters (3 physical therapists and 3 student physical therapists) on 2 separate occasions while performing a single-limb step-down task. Validity was investigated by calculating the 95% limits of agreement, mean absolute differences, and Bland-Altman plots. Reliability was examined by calculating intraclass correlation coefficients and the SE of measure. For validity, the mean absolute difference between rater and criterion reference angle measures ranged from 0.20° to 0.90°. Ninety-five percent of expected errors between rater and criterion reference angle measures were 2.04° or less. For reliability, the intraclass correlation coefficient values for interrater and intrarater reliability were excellent ranging from .994 to .998 with SE of measure ranging from 0.44° to 0.84°. These findings indicate that knee FPPA measures obtained during a single-limb step-down task using the Technique tablet application are valid and reliable, and suitable for clinical use.

Frontal plane lower extremity alignment in adolescent athletes with chronic hip adductor-related groin injury symptoms: A case-control study

ObjectiveTo compare trunk and lower extremity frontal plane projection angles (FPPA) during single leg squat (SLS) performance, perceived hip and groin function and symptoms, and isometric hip strength of adolescent athletes with chronic hip adductor-related groin injury (HARGI) symptoms and age, gender, and sport-matched healthy subjects. DesignCase-control study. SettingJunior Olympic Development Training Centre. ParticipantsTwenty-six athletes at 59.1 ± 60 weeks (range = 12–208 weeks) post-index grade II HARGI injury who had continued sport training (injury group) and 26 control group subjects. Main outcome measuresSLS trunk, hip, and knee FPPA, isometric hip strength standardized to bodyweight, and Copenhagen Hip and Groin Outcome Scores (HAGOS). ResultsThe injury group had greater bilateral knee FPPA, and greater injury side hip FPPA during maximum SLS. Injury group HAGOS subscale scores were lower than control group scores. Hip abductor, adductor, external rotator, and internal rotator strength was lower at the injury side of the injury group compared to the matched control group limb. Forward stepwise multiple regression analysis of the injury group found that 50% of injury side knee FPPA was predicted by hip internal rotator strength and time post-index HARGI; and 47% of injury side hip FPPA was predicted by other side hip flexor strength and the HAGOS function, sport and recreation subscale score (p = 0.002). ConclusionsGreater injury side hip and bilateral knee FPPA during maximum SLS, lower self-reported hip symptom and function scores, and less injury side hip abductor, adductor, external rotator and internal rotator strength suggests that adolescent athletes with chronic HARGI symptoms are at an increased risk for sustaining a non-contact knee injury. Impaired hip internal rotator strength at the side of the chronic HARGI was related to increased knee FPPA, and impaired hip flexor strength at the other side of the HARGI was related to increased hip FPPA. Findings support using SLS performance testing in this athlete group to help determine safe return to sport training readiness.

The Concurrent Validity and Reliability of Single Leg Squat Among Physically Active Females with and without Dynamic Knee Valgus.

BackgroundThe single leg squat (SLS) motion imitates various maneuvers in sports. It is commonly used as a functional test for the lower limb. SLS with two-dimensional (2-D) video analysis is regularly performed in the clinical setting to assess dynamic knee valgus (DKV). However, 2-D video analysis may not be able to demonstrate the same level of accuracy as three-dimensional (3-D) motion analysis.PurposeThis study aimed to determine the within- and between-day reliability as well as the concurrent validity of 2-D and 3-D motion analysis of lower limb kinematics during 45° and 60° SLS among physically active females with and without DKV.Study DesignCross-sectional studyMethodsA total of 34 physically active females (17 individuals with excessive DKV and 17 without DKV) participated in the study. Their DKV was determined based on the cut-off values of knee frontal plane projection angle during drop landing. Their lower limb kinematics during SLS at 45° and 60° knee flexion were captured simultaneously by digital cameras (2-D motion capture) and infrared cameras (3-D motion capture). Intraclass Correlation Coefficient (ICC) was used as an indicator for within- and between-day reliability tests of both groups. Bland-Altman Plot and Pearson correlation were used to examine the validity of 2-D and 3-D motion capture methods in evaluating knee valgus angle.ResultsTwo-dimensional knee FPPA and 3-D knee angle measured during 45° and 60° SLS in normal and excessive DKV groups showed moderate to excellent within-day and between-day reliability (ICC≥ 0.50). The current study showed that the 2-D knee frontal plane projection angle (FPPA) during 45° SLS were valid for the non-dominant leg in both groups. Additionally, the 2-D knee FPPA during 60° SLS were valid for non-dominant leg in excessive DKV group and dominant leg in normal group.ConclusionTwo-dimensional knee FPPA during 45° and 60° SLS also showed high within-and between-day reliability for both groups. The validity of 2-D knee FPPA during SLS depends on the squat depth, stance leg, and presence of DKV.Level of Evidence2B

Association between Selected Screening Tests and Knee Alignment in Single-Leg Tasks among Young Football Players.

This study aimed to examine the relationship between knee valgus in the frontal plane projection angle (FPPA) during single-leg squat (SLS), single-leg landing (SLL), and other selected clinical tests in young athletes. Forty-three young healthy elite football players (age: 13.2 (1.7) years) that were regularly training in a local sports club participated in the study. The FPPA was assessed using 2D video analysis. The screening tests included the passive single-leg raise (PSLR), hip external and internal rotation (hip ER and IR), sit and reach test, weight-bearing lunge test (WBLT), modified star excursion balance test (mSEBT), countermovement jump (CMJ), single-leg hop for distance (SLHD), and age peak height velocity (APHV). There was a significant positive relationship between the knee valgus angles in the SLS test and the sit and reach test (r = 0.34) and a negative relationship with the hip ER ROM (r = −0.34) (p < 0.05). The knee valgus angles in the SLL were negatively associated with the hip IR (r = −0.32) and ER ROM (r = −0.34) and positive associated with the WBLT (r = 0.35) and sit and reach test (r = 0.33) (p < 0.05). Linear regression analysis showed that the results of the hip ER ROM and sit and reach tests were independent predictors of the FPPA in the SLS test (r2 = 0.11, p = 0.03 and r2 = 0.12, p = 0.02, respectively). The conducted study showed that individuals with more hip range of motion, more spine flexion extensibility, and less ankle dorsiflexion ROM may be more likely to experience high degrees of knee valgus in FPPA.

Clinical Significance of the Static and Dynamic Q-angle.

Q-angle represents the resultant force vector of the quadriceps and patellar tendons acting on the patella. An increased Q-angle has been considered a risk factor for many disorders and injuries. This literature review challenges the clinical value of static Q-angle and recommends a more dynamic movement evaluation for making clinical decisions. Although there are many articles about static Q-angle, few have assessed the value of dynamic Q-angle. We searched Scopus and PubMed (until September 2021) to identify and summarize English-language articles evaluating static and dynamic Q-angle, including articles for dynamic knee valgus (DKV) and frontal plane projection angle. We also used textbooks and articles from references to related articles. Although static Q-angle measurement is used systematically in clinical practice for critical clinical decisions, its interpretation and clinical translation present fundamental and intractable limitations. To date, it is acceptable that mechanisms that cause patellofemoral pain and athletic injuries have a stronger correlation with dynamic loading conditions. Dynamic Q-angle has the following three dynamic elements: frontal plane (hip adduction, knee abduction), transverse plane (hip internal rotation and tibia external rotation), and patella behavior. Measuring one out of three elements (frontal plane) illustrates only one-third of this concept. Static Q-angle lacks biomechanical meaning and utility for dynamic activities. Although DKV is accompanied by hip and tibia rotation, it remains a frontal plane measurement, which provides no information about the transverse plane and patella movement. However, given the acceptable reliability and the better differentiation capability, DKV assessment is recommended in clinical practice.

The association and reliability of the frontal plane projection angle during the lateral step down test on knee function in patients with patellofemoral pain

BackgroundThe lateral step-down test is used by physical therapists (PT) to identify movement faults in patients with patellofemoral pain (PFP). The FPPA is a measure of knee valgus and PTs have access to open source video analysis software and high quality smart phones and video cameras to implement 2D video analysis into practice. The purpose of our study was to determine the reliability of PTs measuring the frontal plane projection angle (FPPA) during the lateral step-down test, and to determine if the FPPA was associated with pain, self-reported knee function and fear of movement. MethodsTwenty-two subjects (mean age[SD] = 27.8 [6.6] years, females n = 14, males n = 8) with PFP were analyzed by six PTs using 2D video analysis software. The FPPA was measured during the lateral step down test. Numeric Pain Rating Scale (NPRS), Anterior Knee Pain Scale (AKPS) and the Tampa Scale of Kinesiophobia (TSK) were collected. Intraclass correlation (ICC) was used to assess for PT measurement reliability. Correlations between outcomes were calculated using Spearman correlation coefficient and standard error of measurement (SEM) and minimal detectable change (MDC) were reported. ResultsReliability amongst PTs measuring the FPPA was good (ICC [95 %CI] = 0.85 [0.72–0.93]; SEM = 3.33°, MDC = 9.20°). There were no significant correlations (p > 0.05) between FPPA and NPRS(ρ = -0.046), AKPS(ρ = 0.066), or TSK(ρ = -0.204). ConclusionsAlthough reliability measuring FPPA was good, the large SEM and MDC associated with this measurement may limit its clinical utility in those with PFP.

Efficacy of Treatment Based on the Movement System Impairment Classification in People with Knee Pain: A Study Protocol

Background: Detection of abnormal movement patterns and disorders and their classification into specific sub-categories may result in effective therapeutic choices. Classification of movement system impairments has provided seven sub-categories for movement disorders in the knee joint with specific treatment recommendations for each. Objective: This study aimed to investigate the effectiveness of specific treatments proposed by this classification method and compare the effectiveness of this treatment method with routine ones. Materials and Methods: Participants who met the inclusion criterion were randomly assigned into control and experimental groups after the diagnosis of their movement impairment. Subcategories including patellar lateral glide syndrome and tibiofemoral rotation syndrome were recruited. Experimental groups were treated specifically based on their impairment; however, all control groups received the same routine physiotherapy, regardless of their movement impairment. Two knee function and disability instruments were used, including Knee Injury and Osteoarthritis Outcome Score and the Lower Extremity Functional Scale. Eventually, each experimental group’s outcome scores on the visual analog scale and frontal plane projection angles were compared with those in the control group. Results: Conclusion: We will try to figure out whether the specific treatments based on the movement impairment classification have any benefit over the routine treatment. This would also give clues about the validity of this classification in knee pain. If this is the case, detecting the movement impairment and giving treatment on this basis could be used as a comprehensive guideline.

Reliability and Differences Between Sexes in Landing Mechanics when Performing the Lateral Bound Test.

Background and PurposeAnterior cruciate ligament injuries are prevalent among the athletic population, imposing a heavy economic burden, and the risk of re-injury. Most current biomechanical screening tasks are performed in the sagittal plane, and there is a need for more screening tools that assess sports specific movements in the frontal plane. The purpose of this study was to determine the reliability of and examine differences between sexes in the performance of the Lateral Bound Test (LBT).Materials/MethodsEach subject performed three trials of a LBT which included jumping laterally from one leg over a hurdle and landing on the opposite leg. Two cameras were placed six feet from the landing marker. Maximum dynamic knee valgus using the frontal plane projection angle and knee flexion angle at initial contact and maximal knee flexion were measured upon landing leg using 2D video analysis software. Additionally, video of 10 individuals’ trials were analyzed twice with one week between the analyses to obtain intra-rater reliability while 12 participants were retested one week later to determine test-retest reliability.ResultsThirty healthy subjects, 16 males, 14 females participated. Intra-rater reliability was determined to be excellent for all variables (ICC>0.96). In contrast, the test-retest reliability had greater disparity. Test-retest reliability ranged from poor (ICC = 0.47) to excellent (ICC > 0.90). Significant differences existed between the sexes, including males being significantly taller, weighing more, and demonstrating greater bilateral dynamic knee valgus (p < 0.05). No significant differences existed between sexes for knee flexion angles.ConclusionThe new LBT had excellent intra-rater reliability for assessing dynamic knee valgus and initial and maximum knee flexion angle when performing a functional movement in the frontal plane. Furthermore, males landed with more dynamic knee valgus than females which is contradictory to what has been observed with functional screening tools performed in the sagittal plane.Level of Evidence3b (reliability study)

Comparison of the Frontal Plane Projection Angle and the Dynamic Valgus Index to Identify Movement Dysfunction in Females with Patellofemoral Pain

Comparison of the Frontal Plane Projection Angle and the Dynamic Valgus Index to Identify Movement Dysfunction in Females with Patellofemoral Pain

Analysis of Single Leg Squat and Single Leg Landing Performance Variability among Professional Soccer Players Across a Season

Objectives: This study investigated the performance variability between limb type (dominant versus non-dominant leg) with regard to time (over season with three categories: pre-, start- and end-season) of professional soccer players. Methods: A total of 88 out of 124 male soccer players aged 16-30 years were asked to perform the specific athletic tasks single leg squat (SLS) and single leg landing (SLL) during different times in a full sports season. These functional tasks were evaluated using outcome measures of coefficient of variation, including frontal plane projection angle (FPPA) and hip adduction angle (HAA). Results: No significant difference was observed across all events between the dominant and non-dominant leg of the participants between screening sessions over time, for both SLS and SLL functional activities, except for one event in both second-order coefficient of variation for FFPA (FPPA V2) and HAA in SLS (at the start of season, p =0.006). The variations in FPPA and HA are clinically irrelevant, as no statistically significant differences were observed between limb types (dominant versus non-dominant leg) between screening sessions over a season, thereby suggesting that the performance variability is fairly consistent over time. Conclusions: There is consistency across the sports season in the performance variability of SLS and SLL.

Risk factors for ACL, hamstring strain, and hip/groin injuries in elite Australian female footballers: A prospective study.

Introduction: Female footballers are at high risk of sustaining lower limb injuries, with some of the most prevalent and severe injuries being hamstring strains, hip/groin pain, and knee ligament sprains. However, there is currently limited evidence to guide injury prevention strategies and injury risk assessment testing in female footballers. The aim of this study was to assess risk factors for ACL, hamstring, and hip/groin injuries in elite female footballers. Methods: Data were collected from 321 elite female Australian Football, soccer, and Rugby League players during pre-season. Players underwent field-based assessments of isometric hip adductor and abductor strength (ForceFrame), eccentric knee flexor strength during the Nordic hamstring exercise (NordBord), countermovement jump (CMJ) on dual forceplates (ForceDecks), and a single-leg triple vertical hop (TVH) using a makerless motion capture system (HumanTrak). Players were subsequently followed for injuries for 18 months. Risk factors were identified prospectively using simple and multiple logistic regression and decision tree learning. Results: A total of 12 anterior cruciate ligament (ACL) ruptures, 17 hamstring strains, and 12 hip/groin injuries were recorded. Risk factors for ACL injury included prior ACL injury (standardised odds ratio [OR]=12.3, P<.001), lower body weight normalised adductor torque (OR=2.1, P=.028), greater body weight normalised CMJ peak force (OR=1.9, P=.013), lower CMJ impulse (OR=2.0, P=.037), greater triple vertical hop knee frontal plane projection angle (OR=2.3, P=.014), and greater triple vertical hop lateral trunk flexion (OR=1.7, P=.038). Multiple logistic regression and decision tree models classified ACL injured players with high accuracy (sensitivity=67% and 75% respectively, and specificity=88% and 100% respectively). Risk factors for time-loss hamstring injury included smaller stature (OR=1.8, P=.030), greater between-leg asymmetry in CMJ peak force (OR=2.0, P=.011) and eccentric impulse (OR=1.9, P=.016). There were no statistically significant risk factors for hip/groin injury. Discussion: This is the first study to explore risk factors for lower limb injury in elite female Australian football codes. These results provide insight into the potential modifiable factors associated with subsequent injury in elite female footballers, which may inform player testing batteries and the design of targeted injury risk reduction strategies. Conflict of interest statement: Funding for travel was provided by Vald Performance (Brisbane, Australia) and SMA Research Foundation. My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.

Effects of task and hip-abductor fatigue on lower limb alignment and muscle activation

PurposeFatigue-induced hip-abductor weakness may exacerbate lower-limb misalignments during different dynamic single-leg tasks. We sought to evaluate the effects of fatigue and task on lower limb kinematics and muscle activation and to find associations between measurements obtained in two tasks.MethodsOne-group pretest–posttest design. Seventeen healthy adults (9 W) performed the single-leg squat (SLSQUAT) and the single-leg hop (SLHOP) before and after a hip-abduction fatigue protocol. Hip adduction, knee frontal plane projection angle (knee FPPA) and heel inversion displacement were measured during the eccentric phase of the SLSQUAT and the SLHOP, as well as activation of the gluteus medius (GMed), tensor fascia latae (TFL), peroneus longus (PER) and tibialis anterior (TA). Moments and tasks were compared using a repeated-measures two-way ANOVA. Correlation between tasks was evaluated using Spearman’s correlation.ResultsNo differences in kinematics or activation were found between moments. Hip-adduction displacement (P = 0.005), GMed (P = 0.008) and PER (P = 0.037) activation were higher during SLSQUAT, while TA activation was higher during SLHOP (P < 0.001). No differences were found between tasks in knee FPPA and heel inversion. Hip-adduction and knee FPPA were not correlated between tasks, while ankle inversion displacement was positively correlated (rs = 0.524–0.746). ConclusionDifferent characteristics of SLSQUAT (slower and deeper) seem to have led to increased hip adduction displacement, GMed, and PER activation and decreased TA activation, likely due to higher balance requirements. However, hip-abductor fatigue didn’t influence lower-limb alignment during the tasks. Finally, evaluations should be performed with different single-leg tasks since they don’t give the same lower-limb alignment information.

Distal thigh compression garment improves knee control and safety perceptions during single leg triple-hop for distance

IntroductionFrontal plane knee control is essential to athletic knee injury prevention. AimTo evaluate knee valgus frontal plane projection angle (FPPA), knee safety, and sports movement capability confidence during single leg triple hop for distance (SLTHD) under knee sleeve, distal thigh compression garment (DTCG), and no device (control) conditions. MethodsA single-session, experimental study was performed using a within-subject design, and randomized device order. Two-dimensional FPPA measurements were collected during the final SLTHD landing of 18 healthy female college athletes for each condition. Sports movement capability and knee safety confidence were measured using 10-cm visual analog scale questions. One-way ANOVA assessed group differences, and Pearson correlations delineated FPPA, knee safety and sports movement capability confidence relationships (p < 0.05). ResultsThe DTCG group had less valgus FPPA than the control group. The knee sleeve group had greater knee safety confidence than the control group. The DTCG (r = 0.48) had a moderate positive relationship between mean SLTHD and knee safety confidence. The DTCG group also had a moderate relationship between maximum SLTHD and knee safety confidence (r = 0.52). The DTCG and knee sleeve groups displayed moderate direct, and moderate inverse relationships between FPPA and sports movement capability confidence (r = 0.48 and r = −0.44, respectively). ConclusionReduced FPPA and relationships between maximum SLTHD magnitude and knee safety confidence, and between FPPA magnitude and sports movement capability confidence suggests that the DTCG may enhance pelvic deltoid kinesthetic acuity and dynamic knee stability through iliotibial tract compression. Clinical relevanceThe DTCG was superior to the standard knee sleeve or control conditions for displaying characteristics that might better prevent knee injury, while still enabling effective sports movement capability.