Differences in the Dominant and Non-Dominant Knee Valgus Angle in Junior Elite and Amateur Soccer Players after Unilateral Landing

The effects of fatigue on knee kinematics during unanticipated change of direction in adolescent girl athletes: a comparison between dominant and non-dominant legs

This study was aimed to compare the knee kinematic parameters between dominant and non-dominant legs of adolescent female athletes during change of direction (CoD) in fatigued and unpredictable settings. Knee kinematic parameters on 49 athletes (mean± SD; age = 14.69 ± 0.14 years; mass = 49.05 ± 1.22 kg; height = 1.61 ± 0.08 m) during CoD before and after performing the Bruce protocol and also in predictable and unpredictable setting situations were collected. Kinematic data were recorded at a sampling rate of 200 Hz. The results showed that the dominant leg had significantly 18.7% more flexion (p = 0.001, η = 0.95), 7.1% less valgus (p = 0.001, η = 0.95) and 0.32% lower tibia rotation (p = 0.003, η = 0.16) compared to the non-dominant leg in predictable and pre-fatigue (p < 0.05) conditions. With unpredictable and post-fatigue conditions the dominant limb again demonstrated 17.4% (p = 0.001, η = 0.67), greater knee flexion, 6.8% (0.003,η = 0.97) lower knee valgus and 1.4% (p = 0.001, η = 0.71) less tibiarotation. In conclusion, there may be an increased risk of injury withthe non-dominant leg due to changes in kinematic parameters caused by fatigue and unpredictable CoD manoeuvres.

Effect of fatigue on knee biomechanics during the sidestep cutting manoeuvre: A modelling approach

Loading both lateral and medial compartments is crucial to understanding the effect of muscle fatigue during sidestep cutting. The present study investigated the changes in tibiofemoral contact forces in the medial and lateral compartments and the muscle force contributions during the sidestep-cutting manoeuvre after a handball-specific fatigue protocol. Twenty female handball athletes performed three trials of the sidestep-cutting manoeuvre before (baseline) and after the fatigue protocol. Motion capture and ground reaction forces were measured, and the data were processed in OpenSim. The variables were compared using statistical parametric mapping (SPM), with a significance level of p < 0.05. The results showed a decreased knee flexion angle during fatigue in the early stance phase. In addition, the post-fatigue analysis demonstrated significantly reduced forces in vasti muscles. Similarly, during fatigue, the SPM analysis showed decreased tibiofemoral contact forces in the vertical and anterior directions. Vertical force applied to both medial and lateral condyles demonstrated a significant reduction after the fatigue protocol. These results indicated that forces applied to the tibiofemoral joint were reduced following the fatigue protocol compared to the baseline values. However, no consistent evidence exists that fatigue increases the risk of knee injuries.

Fatigue as a key factor for testing knee stability with single leg drop landing for injury prevention and return to play tests

Objectives

Fatigue can decrease knee stability and increase the injury risk. However, fatigue is rarely being applied throughout movement analysis. The aim of this study was to investigate if the knee stability throughout SLDLs differ between cyclic and acyclic sports, before and after fatigue in general, and between the dominant and non-dominant leg of soccer players.

Methods

A total of 43 active male (n = 34) and female (n = 9) athletes (age: 26.5 ± 7.2) participated in this study with a pre-post-design. Subjects performed a single leg drop landing (SLDL) from a plyobox. For each leg, the two-dimensional frontal plane projection angle (FPPA) was analyzed. After pretesting the shuttle run test was performed until exhaustion, before repeating the measurements.

Results

ANOVA with repeated measures was applied and identified no significance difference for the FPPA between cyclic and acyclic sports (F = 0.98, p = 0.33), a significant difference before and after fatigue (F = 12.49, p = 0.002) and no significant difference between the dominant and non dominant leg of soccer players (F = 4.35, p = 0.26).

Discussion

Fatigue seems to be able to have a significant influence on knee stability in the frontal axis. Therefore, fatigue should be included in motion analysis for injury prevention and return to play tests because during this physical state most injuries happen.

Relationship of Quantitative Measures of Jumping Performance with Gross Motor Development in Typically Developed Preschool Children

Jumping is a key movement developing in the preschool period, but limited studies have reported the determinants of jumping performance and its relationship with gross motor development. This study aimed to determine the correlations among jumping performance, quantitative parameters of jumping, and gross motor development in preschool children. Twenty-one preschool children were recruited from one kindergarten, and fifteen of them with complete data were further analyzed. The quantitative parameters of standing long jump (SLJ) and standing vertical jump (SVJ) were measured using a video-based motion capture system. The gross motor development was measured using the Preschooler Gross Motor Quality Scale (PGMQ). The Spearman's rho value and a linear regression model were used to determine the relationships among the jumping performance, the quantitative measures, and the total PGMQ scores. The results indicate that the jumping performances were significantly correlated with the takeoff velocity, which was predicted by trunk inclination before takeoff in SLJ and by the ranges of trunk inclination during jumping in SVJ. Regression analysis showed that the preschool children with higher normalized jump height had better gross motor development, and that the jump performance and the gross motor development were directly or indirectly predicted by the slope of the hip-to-ankle angle plot during pre-takeoff. In conclusion, this study identifies key components of jumping in jumping performance and gross motor development in preschool children for physical education.

Female Adolescent Soccer Players Utilize Different Neuromuscular Strategies Between Limbs During the Propulsion Phase of a Lateral Vertical Jump

BACKGROUND

Multiplanar dynamic stability is an important unilateral function in soccer performance but has been scarcely examined in female soccer players. The lateral vertical jump task assesses unilateral functional performance, and energy generation contribution examines how each joint (hip, knee, ankle) contributes to the vertical component of the vertical jump phase to measure inter- and intra-limb differences.

PURPOSE

To examine dominant versus non-dominant limb performance using energy generation contribution of the hip, knee, and ankle during the vertical jump component of the lateral vertical jump.

STUDY DESIGN

Cross-sectional observational study.

METHODS

Seventeen healthy, adolescent female soccer players (age 13.4±1.7 years; height 160.6±6.0 cm; mass 53.1±8.2 kg) participated. Quadriceps strength was measured via isokinetic dynamometry. Energy generation contribution (measured from maximal knee flexion to toe off) and vertical jump height were measured during the vertical component of the lateral vertical jump.

RESULTS

There was no significant difference between limbs for quadriceps strength (p=0.64), jump height (p=0.59), or ankle energy generation contribution (p=0.38). Energy generation contribution was significantly greater in the dominant hip (dominant 29.7±8.6%, non-dominant 18.4±6.3%, p<0.001) and non-dominant knee (dominant 22.8±6.8%, non-dominant 36.2±8.5%, p<0.001).

CONCLUSION

High demand on coordination and motor control during the lateral vertical jump and inherent limb dominance may explain different intra-limb strategies for task performance despite jump height symmetry. Non-dominant affinity for stability and dominant compensatory performance may neutralize potential asymmetries. Implications for symmetry in observable outcomes such as jump height must consider underlying internal asymmetries.

LEVELS OF EVIDENCE

3B.

CLINICAL RELEVANCE

Symmetrical findings on functional tasks have underlying internal asymmetries observed here in female adolescent soccer players. The lateral vertical jump may highlight these internal asymmetries (hip- versus knee-dominant movement strategies) due to the high coordinative demand to perform the task. Clinicians should be cognizant of underlying, potentially inherent, asymmetries even when observing functional symmetry in a task.

WHAT IS KNOWN ABOUT THE SUBJECT

Female adolescent soccer players are a high-risk cohort for sustaining anterior cruciate ligament injuries. Limb dominance may play a role in the performance of functional tasks, and limb dominance in soccer players is quite specialized: the dominant limb is the preferred kicking limb, while the non-dominant limb is the preferred stabilizing limb (plant leg). Functional performance in female soccer players has been studied in kicking, dribbling, sprinting, change of direction, and jumping - however, these tasks were measured independent of limb dominance. It remains to be seen how unilateral functional tasks may be affected by limb dominance in female adolescent soccer players.

WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE

This study provides data on functional performance relative to limb dominance in female adolescent soccer players, and captures the lateral vertical jump task in both inter- and intra-limb measures. This highlights that intra-limb strategies to perform a coordinated motor task may be different between limbs, herein attributed to limb dominance. Even if gross motor outputs between limbs are symmetrical (i.e. jump height), the underlying movement strategies to achieve that output may be different (hip- versus knee-dominant movement strategies). These findings are important to research on functional performance measures related to attaining between-limb symmetry, as measures of energy generation contribution open the door for a more thorough understanding of joint-by-joint intra-limb contributions during a functional task.

A Narrative Review of Limb Dominance: Task Specificity and the Importance of Fitness Testing

ABSTRACT

Virgile, A and Bishop, C. A narrative review of limb dominance: Task specificity and the importance of fitness testing. J Strength Cond Res 35(3): 846-858, 2021-Preferential limb function must be sustained through repetitious asymmetrical activities for continuous athletic development and, ultimately, optimal athletic performance. As such, the prevalence of limb dominance and between-limb differences is common in athletes. Severe between-limb differences have been associated with reductions in athletic performance and increased injury risk in athletes. However, in the current literature, the terms limb preference and limb dominance have been used interchangeably. Together, these terms include a limb that is subjectively preferred and one that is objectively dominant in 1 or more performance measures from a variety of athletic tasks. In this review, we (a) discuss reported correspondence between task-specific limb preference and limb dominance outcomes in athletes, (b) provide greater context and distinction between the terms limb preference and limb dominance, and (c) offer pragmatic strategies for practitioners to assess context-specific limb dominance. A limb that is subjectively preferred is not necessarily objectively dominant in 1 or more athletic qualities or sport-specific tasks. Further to this, a limb that is objectively superior in 1 task may not exhibit such superiority in a separate task. Thus, limb preference and limb dominance are both task-specific. As such, we propose that practitioners intentionally select tasks for limb dominance assessment which resemble the most relevant demands of sport. Because limb dominance profiles are inconsistent, we suggest that practitioners increase assessment frequency by integrating limb dominance testing into standard training activities. This will allow practitioners to better understand when changes reflect sport-specific adaptation vs. potential performance or injury ramifications.

Acute Effects of ACL Injury-Prevention Warm-Up and Soccer-Specific Fatigue Protocol on Dynamic Knee Valgus in Youth Male Soccer Players

Childhood anterior cruciate ligament (ACL) injuries—which can pose a major risk to a child’s sporting career—have been on the rise in the last few decades. Dynamic knee valgus (DKV) has been linked to an increased risk of ACL injury. Therefore, the aim of this study was to analyze the acute effects of an ACL injury prevention protocol (ACL-IPP) and a soccer-specific fatigue protocol (SSFP) on DKV in youth male soccer players. The research hypothesis was that DKV would be reduced by the ACL-IPP and increased by the SSFP. Eighteen youth male soccer players were divided according to baseline DKV. Those with moderate or large DKV performed a neuromuscular training protocol based on activation of the abductor and external rotator hip muscles. Those with little or no DKV performed a soccer-specific fatigue protocol. DKV was assessed using the single-leg squat pre- and post-protocols in both legs. The ACL-IPP significantly decreased DKV during single-leg squat (p < 0.01, effect size = 1.39), while the SSFP significantly increased baseline DKV in the dominant leg during single-leg squat (p = 0.012; effect size = 1.74). In conclusion, the ACL-IPP appears to acutely reduce the DKV in youth male soccer players, and the SSFP seems to acutely increase the DKV in those players who showed a light or no DKV in a non-fatigue situation. By using the SSFP, it may be possible to determine which players would benefit from injury prevention programs due to increased DKV during game scenarios, while hip abductor and external rotator neuromuscular training may be beneficial for players who have moderate and severe DKV during single-leg squat under non-fatigued scenarios.

The Effect of Training Experience and Leg Dominance on the Prevalence of Asymptomatic Intraarticular Changes of the Knee Joints in Adult Professional Male Soccer Players

Background

Currently, no data is available regarding the association between professional experience or limb dominance and the prevalence of asymptomatic knee joint lesions in adult professional male soccer players.

Hypothesis

The prevalence of the accumulated changes increases with training experience. This is especially true for the dominant leg, which is involved in a large proportion of the athletes’ movements.

Study Design

Level 2 cross-sectional cohort study

Methods

MRI was used to assess the condition of 94 knee joints in 47 adult professional male soccer players (mean age 25.7 ± 4.6 years, BMI 22.8 ± 1.4). Previous surgery on joints was an exclusion criterion. No football player had knee injuries (including fresh bruises) for at least 3 months before the examination. All the scans were performed using a 1.5T MRI scanner and a slice thickness of 3 mm. The images were blindly analyzed by two experienced radiologists. We analyzed all the three compartments of the knee joint. We consider a chondral lesion already from grade I in modified Noyes and Stabler classification system. To assess the influence of soccer training experience, all players were divided into two groups: group 1 formed from players with less than 20 years of experience and group 2 with more than 20 years of experience.

Results

One hundred percent of the soccer players had at least one chondral and meniscal lesion.

In both legs, the posterior horn of the medial meniscus (95.6%) was the most frequent site of injury. Most of the injuries were classified as grade II injuries (73.3% for the dominant and 75.6% for the non-dominant leg).

Experience and age of the athletes significantly increased the probability of subcortical bone lesions. They were significantly positively correlated with the grades of patellar lesions and lesions of the patellar surface of the femur and significantly negatively correlated with the grades of lesions of posterior horn of lateral meniscus and anterior horn of medial meniscus.

No statistically significant differences in the prevalence and grades of cartilage and meniscal lesions in the dominant and non-dominant limb were observed.

Conclusion

Soccer practice is associated with the increased prevalence of asymptomatic chondral and meniscal lesions.

The probability of subcortical bone lesions significantly increases with training experience and age. These factors are also positively correlated with the grades of patellar lesions and lesions of the patellar surface of the femur.

The prevalence and grade of asymptomatic chondral and meniscal lesions is independent of leg dominance.

Static loading of the knee joint results in modified single leg landing biomechanics

Background

External loading of the ligamentous tissues induces mechanical creep, which modifies neuromuscular response to perturbations. It is not well understood how ligamentous creep affects athletic performance and contributes to modifications of knee biomechanics during functional tasks.

Hypothesis/purpose

The purpose of this study was to examine the mechanical and neuromuscular responses to single leg drop landing perturbations before and after passive loading of the knee joint.

Methods

Descriptive laboratory study. Male (n = 7) and female (n = 14) participants’ (21.3 ± 2.1 yrs., 1.69 ± 0.09 m, 69.3 ± 13.0 kg) right hip, knee, and ankle kinematics were assessed during drop landings performed from a 30 cm height onto a force platform before and after a 10 min creep protocol. Electromyography (EMG) signals were recorded from rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), semimembranosus (SM), and biceps femoris (BF) muscles. The creep protocol involved fixing the knee joint at 35° during static loading with perpendicular loads of either 200 N (males) or 150 N (females). Maximum, minimum, range of motion (ROM), and angular velocities were assessed for the hip, knee, and ankle joints, while normalized EMG (NEMG), vertical ground reaction forces (VGRF), and rate of force development (RFD) were assessed at landing using ANOVAs. Alpha was set at 0.05.

Results

Maximum hip flexion velocity decreased (p < 0.01). Minimum knee flexion velocity increased (p < 0.02). Minimum knee ad/abduction velocity decreased (p < 0.001). Ankle ROM decreased (p < 0.001). aVGRF decreased (p < 0.02). RFD had a non-significant trend (p = 0.076). NAEMG was significant between muscle groups (p < 0.02).

Conclusion

Distinct changes in velocity parameters are attributed to the altered mechanical behavior of the knee joint tissues and may contribute to changes in the loading of the leg during landing.

Curve analyses reveal altered knee, hip, and trunk kinematics during drop-jumps long after anterior cruciate ligament rupture

BACKGROUND

Anterior cruciate ligament (ACL) ruptures may lead to knee dysfunctions later in life. Single-leg tasks are often evaluated, but bilateral movements may also be compromised. Our aim was to use curve analyses to examine double-leg drop-jump kinematics in ACL-reconstructed, ACL-deficient, and healthy-knee cohorts.

METHODS

Subjects with unilateral ACL ruptures treated more than two decades ago (17-28years) conservatively with physiotherapy (ACL_PT, n=26) or in combination with reconstructive surgery (ACL_R, n=28) and healthy-knee controls (n=25) performed 40-cm drop-jumps. Three-dimensional knee, hip, and trunk kinematics were analyzed during Rebound, Flight, and Landing phases. Curves were time-normalized and compared between groups (injured and non-injured legs of ACL_PT and ACL_R vs. non-dominant and dominant legs of controls) and within groups (between legs) using functional analysis of variance methods.

RESULTS

Compared to controls, ACL groups exhibited less knee and hip flexion on both legs during Rebound and greater knee external rotation on their injured leg at the start of Rebound and Landing. ACL_R also showed less trunk flexion during Rebound. Between-leg differences were observed in ACL_R only, with the injured leg more internally rotated at the hip. Overall, kinematic curves were similar between ACL_R and ACL_PT. However, compared to controls, deviations spanned a greater proportion of the drop-jump movement at the hip in ACL_R and at the knee in ACL_PT.

CONCLUSIONS

Trunk and bilateral leg kinematics during double-leg drop-jumps are still compromised long after ACL-rupture care, independent of treatment. Curve analyses indicate the presence of distinct compensatory mechanisms in ACL_PT and ACL_R compared to controls.