Knee Abduction Moment Research Articles

Hip Strategy During Landing Reduces Knee Abduction Moment In Collegiate Soccer Players

Hip Strategy During Landing Reduces Knee Abduction Moment In Collegiate Soccer Players

A predictive model to estimate knee-abduction moment: implications for development of a clinically applicable patellofemoral pain screening tool in female athletes.

Prospective measures of high external knee-abduction moment (KAM) during landing identify female athletes at increased risk of patellofemoral pain (PFP). A clinically applicable screening protocol is needed. To identify biomechanical laboratory measures that would accurately quantify KAM loads during landing that predict increased risk of PFP in female athletes and clinical correlates to laboratory-based measures of increased KAM status for use in a clinical PFP injury-risk prediction algorithm. We hypothesized that we could identify clinical correlates that combine to accurately determine increased KAM associated with an increased risk of developing PFP. Descriptive laboratory study. Biomechanical laboratory. Adolescent female basketball and soccer players (n = 698) from a single-county public school district. We conducted tests of anthropometrics, maturation, laxity, flexibility, strength, and landing biomechanics before each competitive season. Pearson correlation and linear and logistic regression modeling were used to examine high KAM (>15.4 Nm) compared with normal KAM as a surrogate for PFP injury risk. The multivariable logistic regression model that used the variables peak knee-abduction angle, center-of-mass height, and hip rotational moment excursion predicted KAM associated with PFP risk (>15.4 NM of KAM) with 92% sensitivity and 74% specificity and a C statistic of 0.93. The multivariate linear regression model that included the same predictors accounted for 70% of the variance in KAM. We identified clinical correlates to laboratory measures that combined to predict high KAM with 92% sensitivity and 47% specificity. The clinical prediction algorithm, including knee-valgus motion (odds ratio [OR] = 1.46, 95% confidence interval [CI] = 1.31, 1.63), center-of-mass height (OR = 1.21, 95% CI = 1.15, 1.26), and hamstrings strength/body fat percentage (OR = 1.80, 95% CI = 1.02, 3.16) predicted high KAM with a C statistic of 0.80. Clinical correlates to laboratory-measured biomechanics associated with an increased risk of PFP yielded a highly sensitive model to predict increased KAM status. This screening algorithm consisting of a standard camcorder, physician scale for mass, and handheld dynamometer may be used to identify athletes at increased risk of PFP.

Anticipatory postural adjustments during cutting manoeuvres in football and their consequences for knee injury risk

Anticipatory postural adjustments (APAs), i.e. preparatory positioning of the head, the trunk and the foot, are essential to initiate cutting manoeuvres during football games. The aim of the present study was to determine how APA strategies during cutting manoeuvres are influenced by a reduction of the time available to prepare the movement.Thirteen football players performed different cutting tasks, with directions of cutting either known prior to the task or indicated by a light signal occurring 850, 600 or 500 ms before ground contact.With less time available to prepare the cutting manoeuvre, the head was less orientated towards the cutting direction (P = 0.033) and the trunk was even more rotated in the opposite direction (P = 0.002), while the foot placement was not significantly influenced. Moreover, the induced higher lateral trunk flexion correlated with the increased knee abduction moment (r = 0.41; P = 0.009).Increasing lateral trunk flexion is the main strategy used to successfully perform a cutting manoeuvre when less time is available to prepare the movement. However, higher lateral trunk flexion was associated with an increased knee abduction moment and therefore an increased knee injury risk. Reducing lateral trunk flexion during cutting manoeuvres should be part of training programs seeking the optimisation of APAs.

Physiotherapists can identify female football players with high knee valgus angles during vertical drop jumps using real-time observational screening.

Clinical measurement, controlled laboratory study. To assess the relationships among real-time observational screening of frontal plane knee control and knee valgus angles and abduction moments calculated from 3-D motion analysis during a vertical drop jump. A secondary purpose was to investigate interrater agreement for 3 independent physiotherapists. Current approaches to screen for anterior cruciate ligament injury risk are based on complex biomechanical analyses or 2-dimensional video reviews. There is a need for simple and efficient, low-cost screening methods. Sixty Norwegian elite female football (soccer) players performed a vertical drop-jump task. Using real-time observational screening, 3 physiotherapists independently scored each participant's frontal plane knee control as good, reduced, or poor, based on specific criteria. Screening test scores were correlated to frontal plane knee kinematics and kinetics using 3-D motion analysis. Interrater agreement was determined using kappa correlation coefficients. Knee valgus angles differed significantly among players rated as having poor, reduced, or good knee control (10.3° ± 3.4°, 5.4° ± 4.1°, and 1.9° ± 4.3°, respectively). The correlation between the observation test scores and valgus angles was moderate for all raters (0.54-0.60, P≤.001), but the observation scores correlated poorly with abduction moments (0.09-0.11, P>.05). The highest discriminative accuracy was found for knee valgus angles across all raters (area under the receiver-operating-characteristic curve, 0.85-0.89). The interrater agreement between the physiotherapists was substantial to almost perfect, with percentage agreement and kappa coefficients ranging from 70% to 95% and 0.52 to 0.92, respectively. Physiotherapists can reliably identify female athletes with high knee valgus angles in a vertical drop-jump landing using real-time observational screening.

Effects of increased step width on frontal plane knee biomechanics in healthy older adults during stair descent

BackgroundPeak internal knee abduction moment is a common surrogate variable associated with medial compartment knee loading. Stair descent has been shown to yield a greater peak knee abduction moment compared to level-walking. Changes in step width (SW) may lead to changes in frontal plane lower extremity limb alignment in the frontal plane and alter peak knee abduction moment. The purpose of this study was to investigate the effects of increased SW on frontal plane knee biomechanics during stair descent in healthy older adults. MethodsTwenty healthy adults were recruited for the study. A motion analysis system was used to obtain three-dimensional lower limb kinematics during testing. An instrumented 3-step staircase with two additional customized wooden steps was used to collect ground reaction forces (GRF) data during stair descent trials. Participants performed five stair descent trials at their self-selected speed using preferred, wide (26% leg length), and wider (39% leg length) SW. ResultsThe preferred normalized SW in older adults during stair descent was 20% of leg length. Wide and wider SW during stair descent reduced both first and second peak knee adduction angles and abduction moments compared to preferred SW in healthy adults. ConclusionsIncreased SW reduced peak knee adduction angles and abduction moments. The reductions in knee abduction moments may have implications in reducing medial compartment knee loads during stair descent.

High knee abduction moments are common risk factors for patellofemoral pain (PFP) and anterior cruciate ligament (ACL) injury in girls: Is PFP itself a predictor for subsequent ACL injury?

BackgroundIdentifying risk factors for knee pain and anterior cruciate ligament (ACL) injury can be an important step in the injury prevention cycle.ObjectiveWe evaluated two unique prospective cohorts with similar populations...

DIFFERENCES IN NEUROMUSCULAR ACTIVITY OF QUADRICEPS AND HAMSTRINGS WITH RESPECT TO DIFFERENT LANDING PATTERNS IN FEMALE ATHLETES

BackgroundA high knee abduction moment (KAM) and an erect movement pattern during landing have been suggested as anterior cruciate ligament (ACL) injury risk factors. Previous research focused mainly on determination...

ARE TWO-DIMENSIONAL MEASURED SAGITTAL PLANE KINEMATICS RELATED TO THREE-DIMENSIONAL JOINT LOADING DURING THE DROP VERTICAL JUMP TEST?

BackgroundAcute and overuse knee injuries are common in sports involving jump-landing movements, especially in female athletes. More erect sagittal plane movement patterns are believed to increase injury risk. Whilst three-dimensional...

VISUAL ASSESSMENT OF ACL INJURY RISK: CAN EXPERTISE BE ACHIEVED?

BackgroundIdentifying individuals with a high risk for ACL injury is important for injury prevention. Current screening methods exist but rely on expensive and time consuming biomechanical analysis, limiting large scale...

THE EFFECTS OF AN INJURY PREVENTION PROGRAM ON LIMB DOMINANCE NEUROMECHANICS

BackgroundDespite numerous injury prevention programs (IPP), the incidence of anterior cruciate ligament (ACL) in athletics remains high. Few IPP have quantified biomechanical changes in the dominant and non-dominant leg.ObjectiveTo evaluate...

THE EFFECTS OF FUNCTIONAL GARMENT ON THE JUMP LANDING TASK

BackgroundThe effectiveness of wearing a brace to prevent sports injuries of the knee remains controversial. We examined the impact of functional newly developed garments.ObjectiveTo investigate the biomechanics of the knee...

EFFECT OF INJURY PREVENTION TRAINING ON KNEE MECHANICS IN FEMALE ADOLESCENTS DURING PUBERTY

BackgroundFemale adolescents change their landing mechanics during puberty. It is unknown whether implementation of anterior cruciate ligament (ACL) injury prevention training reduces the loss of knee control in female athletes...

Does increasing step width alter knee biomechanics in medial compartment knee osteoarthritis patients during stair descent?

BackgroundResearch shows that one of the first complaints from knee osteoarthritis (OA) patients is difficulty in stair ambulation due to knee pain. Increased step width (SW) has been shown to reduce first and second peak internal knee abduction moments, a surrogate variable for medial compartment knee joint loading, during stair descent in healthy older adults. This study investigates the effects of increased step width (SW) on knee biomechanics and knee pain in medial compartment knee OA patients during stair descent. MethodsThirteen medial compartment knee OA patients were recruited for the study. A motion analysis system was used to obtain three-dimensional joint kinematics. An instrumented staircase was used to collect ground reaction forces (GRF). Participants performed stair descent trials at their self-selected speed using preferred, wide, and wider SW. Participants rated their knee pain levels after each SW condition. ResultsIncreased SW had no effect on peak knee abduction moments and knee pain. Patients reported low levels of knee pain during all stair descent trials. The 2nd peak knee adduction angle and frontal plane GRF at time of 2nd peak abduction moment were reduced with increasing SW. ConclusionsThe findings suggest that increases in SW may not influence knee loads in medial compartment knee OA patients afflicted with low levels of knee pain during stair descent.

Effect of a Novel Movement Strategy in Decreasing ACL Risk Factors in Female Adolescent Soccer Players

To determine the effect of a novel movement strategy incorporated within a soccer warm-up on biomechanical risk factors for anterior cruciate ligament injury during 3 sport-specific movement tasks. Single-blind, randomized controlled clinical trial. Laboratory setting. Twenty top-tier female teenage soccer players. Subjects were randomized to the Core Position and Control movement strategy (Core-PAC) warm-up or standard warm-up, which took place before their regular soccer practice over a 6-week period. The Core-PAC focuses on getting the centre of mass closer to the plant foot or base of support. Peak knee flexion angle and abduction moments during a side-hop (SH), side-cut, and unanticipated side-cut task after the 6 weeks with (intervention group only) and without a reminder to use the Core-PAC strategy. The Core-PAC group increased peak flexion angles during the SH task [mean difference = 6.2 degrees; 95% confidence interval (CI), 1.9-10.5 degrees; effect size = 1.01; P = 0.034] after the 6-week warm-up program without a reminder. In addition, the Core-PAC group demonstrated increased knee flexion angles for the side-cut (mean difference = 8.5 degrees; 95% CI, 4.8-12.2 degrees; ES = 2.02; P = 0.001) and SH (mean difference = 10.0 degrees; 95% CI, 5.7-14.3 degrees; ES = 1.66; P = 0.001) task after a reminder. No changes in abduction moments were found. The results of this study suggest that the Core-PAC may be one method of modifying high-risk soccer-specific movements and can be implemented within a practical, team-based soccer warm-up. The results should be interpreted with caution because of the small sample size.

Shoe traction and surface compliance affect performance of soccer-related movements

Purpose: To determine how shoe-surface interaction, specifically traction and compliance, affects performance and biomechanics of soccer-related movements.Methods: Third generation artificial turf was installed in the laboratory to allow for kinetic and kinematic data collection both on the turf and on a laboratory surface (Pulastic sports surface). Twelve male athletes performed five 5 m sprint accelerations and five 180° sprint turns in three different shoe-surface conditions (indoor soccer shoe on the laboratory surface, indoor soccer shoe on the turf surface, soccer cleat on turf surface). Comparisons between the indoor shoe across surfaces indicated compliance effects and comparisons between the cleat and indoor shoe on turf indicated traction effects.Results: Performance increased for the sprint acceleration in the indoor shoe on the turf compared to the laboratory (1.04 s vs. 1.08 s); however, no further increase in acceleration performance occurred with the soccer cleat. For the turn movement, no change in performance occurred comparing the indoor shoe across surfaces however an increase in turn performance was seen when using the soccer cleat on turf compared to the indoor shoe (2.67 s vs. 2.56 s). The cleat had both increased utilised translational and rotational traction compared to the indoor shoe on turf for the turn movement. The cleat also resulted in increased ankle eversion moments as well as increased knee abduction and external rotation moments compared to the indoor shoe on the turf surface for the turn movement.Conclusion: Both compliance and traction shoe-surface characteristics affect performance; however, the effects of the different characteristics are different depending on the movement type.

The influence of incline walking on joint mechanics

Walking is a popular form of exercise and is associated with many health benefits; however, frontal-plane knee joint loading brought about by a large internal knee-abduction moment and cyclic loading could lead to cartilage degeneration over time. Therefore, knee joint mechanics during an alternative walking exercise needs to be analyzed. The purpose of this study was to examine the lower-extremity joint mechanics in the frontal and sagittal planes during incline walking. Fifteen healthy males walked on a treadmill at five gradients (0%, 5%, 10%, 15%, and 20%) at 1.34m/s, and lower-extremity joint mechanics in the frontal and sagittal planes were quantified. The peak internal knee-abduction moment significantly decreased from the level walking condition at all gradients except 5%. Also, a negative relationship between the internal knee-abduction moment and the treadmill gradient was found to exist in 10% increments (0–10%, 5–15%, and 10–20%). The decrease in the internal knee-abduction moment during incline walking could have positive effects on knee joint health such as potentially reducing cartilage degeneration of the knee joint, reducing pain, and decreasing the rate of development of medial tibiofemoral osteoarthritis. This would be beneficial for a knee surgery patient, obese persons, and older adults who are using incline walking for rehabilitation and exercise protocols. Findings from the current study can provide guidance for the development of rehabilitation and exercise prescriptions incorporating incline walking.

Comparative Adaptations of Lower Limb Biomechanics During Unilateral and Bilateral Landings After Different Neuromuscular-Based ACL Injury Prevention Protocols

Potentially valuable anterior cruciate ligament (ACL) injury prevention strategies are lengthy, limiting training success. Shorter protocols that achieve beneficial biomechanical adaptations may improve training effectiveness. This study examined whether core stability/balance and plyometric training can modify female landing biomechanics compared with the standard neuromuscular and no training models. Forty-three females had lower limb biomechanics analyzed during unilateral and bilateral landings immediately before and after a 6-week neuromuscular or no training programs. Sagittal and frontal plane hip and knee kinematics and kinetics were submitted to 3-way repeated-measures analyses of variance to test for the main and interaction effects of training group, landing type, and testing time. Greater peak knee flexion was evident in the standard neuromuscular group following training, during both bilateral (p = 0.027) and unilateral landings (p = 0.076 and d = 0.633). The plyometric group demonstrated reduced hip adduction (p = 0.010) and greater knee flexion (p = 0.065 and d = 0.564) during bilateral landings following training. The control group had significant reduction in peak stance knee abduction moment (p = 0.003) posttraining as compared with pretraining. The current outcomes suggest that significant biomechanical changes are possible by an isolated plyometric training component. The benefits, however, may not be evident across all landing types, seemingly limited to simplistic, bilateral landings. Integrated training protocols may still be the most effective training model, currently improving knee flexion posture during both bilateral and unilateral landings following training. Future prevention efforts should implement integrated training protocols that include plyometric exercises to reduce ACL injury risk of female athletes.

The effect of changing toe direction on knee kinematics during drop vertical jump: a possible risk factor for anterior cruciate ligament injury

The purpose of this study was to examine the effect of changing toe direction on knee kinetics and kinematics associated with anterior cruciate ligament injury during drop vertical jumps. Fourteen females performed drop vertical jumps under three toe conditions (natural, toe-in, and toe-out). The knee kinetics and kinematics during landing were evaluated using a motion analysis system. Results under three toe conditions were compared using a one-way repeated measures analysis of variance and a post hoc Bonferroni test. Toe-in landing was associated with a significantly greater knee abduction angle, tibial internal rotation angle, and knee abduction moment than the natural and toe-out conditions. Toe-out landing was associated with significantly greater tibial internal rotational angular velocity. Changing toe direction significantly affects knee kinetics and kinematics during landing. It is important to avoid changing toe direction excessively inward or outward during landing to prevent the increases in knee abduction and tibial internal rotation which might increase the risk of ACL injury. Prognosis, Level IV.

Inter-joint sharing of total support moments in the lower extremities during gait in narrow-heeled shoes of different heights

The study aimed to investigate the influence of the base and height of shoe heels on the total support moment (Ms) and individual joint contributions during gait. Fifteen healthy females walked barefoot and with narrow-heeled shoes (heel heights: 3.9, 6.3 and 7.3 cm) while kinematic and kinetic data were measured. Compared with the barefoot condition, the subjects maintained unaltered Ms in the sagittal plane in shod conditions. This was achieved by increasing the knee extensor moment to compensate for the diminished ankle plantarflexor moments in medium and high heel conditions. In the frontal plane, subjects in shod conditions had to sustain an increased Ms for balance control during late single-leg stance with increased knee abductor and ankle pronator moments as a result of the reduced base of the heels. The results will be helpful for future shoe designs to reduce fall risks and prevent relevant musculoskeletal problems

Gait pattern in 9-11-year-old children with generalized joint hypermobility compared with controls; a cross-sectional study

BackgroundTo study differences in gait patterns in 10-year-old children with Generalized Joint Hypermobility (GJH) and with no GJH (NGJH).MethodsA total of 37 children participated (19 GJH, 18 NGJH, mean age 10.2 (SD 0.5) years). Inclusion criteria for GJH were a Beighton score of ≥5, with at least one hypermobile knee joint; for NGJH a Beighton score of ≤4, and no hypermobile knees and for both groups no knee pain during the previous week. All children were recorded by five video cameras, while they walked across three force platforms. Net joint moments were calculated in 3D by inverse dynamics and peak values provided input to statistical analyses.ResultsIn the frontal plane, children with GJH had a significantly lower peak knee abductor moment and peak hip abductor moment. In the sagittal plane, the peak knee flexor moment and the peak hip extensor moment were significantly lower in the GJH group although the absolute difference was small.ConclusionsThe walking pattern was the same for children with GJH and for healthy children, as there were no differences in kinematics, but it was, however, performed with different kinetics. Children with GJH walked with lower ankle, knee and hip joint moments compared to children with NGJH. However, the clinical importance of these differences during normal gait is unknown. To obtain this knowledge, children with GJH must be followed longitudinally.Trial registrationThe study was approved by the Committee on Biomedical Research Ethics for Copenhagen and Frederiksberg, Denmark (jnr. KF01-2006-178).