The relationship between anterior tibial shear force during a jump landing task and quadriceps and hamstring strength

Effect of different landing actions on knee joint biomechanics of female college athletes: Based on opensim simulation

Background: The anterior cruciate ligament (ACL) is one of the most injurious parts of the knee in the biomechanical environment during landing actions. The purpose of this study was to compare the lower limb differences in movement patterns, muscle forces and ACL forces during drop landing (DL), drop vertical jump (DVJ) and forward vertical jump (FVJ).

Methods: Eleven basketball and volleyball female college athletes (Division II and I) were recruited. Landing actions of DL, DVJ and FVJ, kinematics and dynamics data were collected synchronously using a motion capture system. OpenSim was used to calculate the ACL load, knee joint angle and moment, and muscle force.

Results: At initial contact, different landing movements influenced knee flexion angle; DL action was significantly less than FVJ action (p = 0.046). Different landing actions affected quadriceps femoris forces; FVJ was significantly greater than DL and DVJ actions (p = 0.002 and p = 0.037, respectively). However, different landing movements had no significant effects on other variables (knee extension moment, knee valgus angle and moment, hamstring and gastrocnemius muscle forces, and ACL forces) (p > 0.050).

Conclusion: There was no significant difference in the knee valgus, knee valgus moment, and the ACL forces between the three landing actions. However, knee flexion angle, knee extension moments sagittal factors, and quadriceps and gastrocnemius forces are critical factors for ACL injury. The DL action had a significantly smaller knee flexion angle, which may increase the risk of ACL injury, and not recommended to assess the risk of ACL injuries. The FVJ action had a larger knee flexion angle and higher quadriceps femoris forces that were more in line with daily training and competition needs. Therefore, it is recommended to use FVJ action in future studies on risk assessment of ACL injuries and injury prevention in female college athletes.

Sexual Dimorphisms in Anterior Cruciate Ligament Injury: A Current Concepts Review

Background:

Although most anterior cruciate ligament (ACL) injuries occur in male athletes, female athletes are consistently observed to be at a higher risk for sports-specific ACL injury.

Purpose:

To provide a thorough review of what is known about the sexual dimorphisms in ACL injury to guide treatment and prevention strategies and future research.

Study Design:

Narrative review.

Methods:

We conducted a comprehensive literature search for ACL-related studies published between January 1982 and September 2017 to identify pertinent studies regarding ACL injury epidemiology, prevention strategies, treatment outcomes, and dimorphisms. By performing a broad ACL injury search, we initially identified 11,453 articles. After applying additional qualifiers, we retained articles if they were published in English after 1980 and focused on sex-specific differences in any of 8 different topics: sex-specific reporting, difference in sports, selective training, hormonal effects, genetics, neuromuscular and kinematic control, anatomic differences, and outcomes.

Results:

A total of 122 articles met the inclusion criteria. In sum, the literature review indicated that female athletes are at significantly higher risk for ACL injuries than are their male counterparts, but the exact reasons for this were not clear. Initial studies focused on intrinsic differences between the sexes, whereas recent studies have shifted to focus on extrinsic factors to explain the increased risk. It is likely both intrinsic and extrinsic factors contribute to this increased risk, but further study is needed. In addition to female patients having an increased risk for ACL injuries, they are less likely than are male patients to undergo reconstructive surgery, and they experience worse postsurgical outcomes. Despite this, reconstructive surgery remains the gold standard when knee stability, return to sports, and high functional outcome scores are the goal, but further research is needed to determine why there is disparity in surgical rates and what surgical techniques optimize postsurgical outcomes for female patients.

Conclusion:

Male athletes often predominated the research concerning ACL injury and treatment, and although sex-specific reporting is progressing, it has historically been deficient. ACL injuries, prevention techniques, and ACL reconstruction require further research to maximize the health potential of at-risk female athletes.

Differences in Muscle Activity and Kinetics Between the Goblet Squat and Landmine Squat in Men and Women

ABSTRACT

Collins, KS, Klawitter, LA, Waldera, RW, Mahoney, SJ, and Christensen, BK. Differences in muscle activity and kinetics between the goblet squat and landmine squat in men and women. J Strength Cond Res 35(10): 2661-2668, 2021-Squat exercise variations are widely used and extensively researched. However, little information exists on the goblet squat (GBS) and landmine squat (LMS) and differences between men and women. This study investigated the differences in muscle activity and kinetics between the GBS and the LMS in 16 men and 16 women. Five repetitions of each squat type were performed loaded at 30% of their body mass. Vertical and anteroposterior ground reaction forces for the eccentric and concentric phases and peak vertical force were recorded with a force plate. Electromyographic (EMG) signals were recorded for the vastus medialis (VM), vastus lateralis (VL), semitendinosus (ST), and biceps femoris (BF). Normalized mean EMG values and ground reaction forces were analyzed with repeated measures analysis of variance (p < 0.05). Significant main effects for squat condition and sex were found. The LMS reduced activity in the quadriceps (VM and VL) muscles and vertical forces, while increasing posterior horizontal forces. In the LMS, men showed decreased ST activity, whereas women had decreased BF activity. Women exhibited greater quadriceps activity in both the GBS and LMS and greater ST in the LMS. Women also produced greater eccentric vertical force in both the GBS and LMS and less posterior horizontal forces in the LMS. The LMS may be useful to balance hamstring to quadriceps activity, increase horizontal loading, and reduce vertical loading. Conversely, the GBS can better target quadriceps activity and increase vertical loading. Sex differences should be considered for training programs that include the GBS and LMS.

Assessing thigh muscle balance of male athletes with special emphasis on eccentric hamstring strength

Background: Hamstring strength is important to prevent thigh muscle and knee injuries. Different antagonist-agonist relationships of thigh muscle strength are applied to estimate the injury risk e.g. the intersection point of eccentric hamstring (Hecc) and concentric quadriceps (Qcon) moment-knee flexion angle curves (dynamic control ratio at the equilibrium point = DCRe) and the dynamic control ratio (DCR = Hecc:Qcon). Objective: The aim was to quantify the relationships between DCR, DCRe moments and angles as well as their correlations with peak moments and contractional work of eccentric hamstring and concentric quadriceps exercise. Methods: This cross-sectional study included data from 238 healthy male participants of different sports. They conducted unilateral isokinetic tests obtained at 30°/s and 150°/s for the hamstrings (prone) and the quadriceps (supine). Results: Correlations between DCR and DCRe moments were significant, but weak to moderate in strength (R²_30°/s = 20%, R²_150°/s = 26%). In contrast to DCR (25% ≤ R² ≤ 46%), DCRe moments (80% ≤ R² ≤ 86%) showed very strong relations with peak moments and contractional work of eccentric hamstring exercise. Discussion: DCR and DCRe assess thigh balance by using the same isokinetic raw data. However, weak relations became apparent. DCRe moments were stronger related to eccentric hamstring strength and work than DCR. Therefore, the DCRe moment may serve as meaningful measure of thigh muscle balance because increased eccentric hamstring strength promotes dynamic joint stability and minimizes injury risk.

Relationship of Knee Forces to Subjective Function Pre- and Post-ACL Reconstruction

PURPOSE

Although basic objective measures (e.g., knee laxity, strength, and hop tests) have been related to subjective measures of function, associations between knee-specific objective and subjective measures have yet to be completed. The objective was to determine if knee joint contact and ligament forces differ between pre- and post-anterior cruciate ligament (ACL) reconstructed states and if these forces relate to their patient's respective subjective functional ability scores.

METHODS

Twelve patients performed a hopping task before and after reconstruction. Magnetic resonance images and OpenSim were used to develop patient-specific models in static optimization and joint reaction analyses. Questionnaires concerning each patient's subjective functional ability were also collected and correlated with knee joint contact and ligament forces.

RESULTS

No significant differences were observed between deficient and reconstructed groups with respect to knee joint contact or ligament forces. Nevertheless, there were several significant (P < 0.05) moderate to strong correlations between subjective and objective measures including Tegner activity level to contact force in both states (r = 0.67-0.76) and International Knee Documentation Committee to compressive and anterior shear forces (r = 0.64-0.66).

CONCLUSION

Knee-specific objective measures of a patient's functional capacity can represent their subjective ability, which explains this relationship to a greater extent than past anatomical and gross objective measures of function. This consolidation is imperative for improving the current rehabilitation schema as it allows for external validation of objective and subjective functional measures. With poor validation of subjective function against objective measures of function, the reinjury rate is unlikely to diminish, continuing the heavy financial burden on health care systems.

KNEE ISOKINETIC TORQUE IMBALANCE IN FEMALE FUTSAL PLAYERS

ABSTRACT Introduction: The specificity of sports training can lead to muscle specialization with a possible change in the natural hamstring/quadriceps torque ratio (HQ ratio), constituting a risk factor for muscle injury at the joint angles in which muscle imbalance may impair dynamic stability. Objective: The aim was to evaluate the torque distribution of the hamstrings and quadriceps and the HQ ratio throughout the range of motion in order to identify possible muscle imbalances at the knee of female futsal athletes. Methods: Nineteen amateur female futsal athletes had their dominant limb HQ ratio evaluated in a series of five maximum repetitions of flexion/extension of the knee at 180°/second in the total joint range of motion (30° to 80°). The peak flexor and extensor torque and the HQ ratio (%) were compared each 5° of knee motion using one-way repeated measures ANOVA and Tukey’s post hoc test (p<0.05) to determine the joint angles that present muscular imbalance. Results: Quadriceps torque was higher than 50° to 60° of knee flexion, while hamstrings torque was higher than 55° to 65°. The HQ ratio presented lower values than 30° to 45° of knee flexion and four athletes presented values lower than 60%, which may represent a risk of injury. However, the HQ ratio calculated by the peak torque showed only one athlete with less than 60%. Conclusion: The HQ ratio analyzed throughout the knee range of motion allowed identifying muscle imbalance at specific joint angles in female futsal players.

Isokinetic angle-specific moments and ratios characterizing hamstring and quadriceps strength in anterior cruciate ligament deficient knees

This study is intended to find more effective and robust clinical diagnostic indices to characterize muscle strength and coordination alternation following anterior cruciate ligament (ACL) rupture. To evaluate angle-specific moments and hamstring (H)/quadriceps (Q) ratios, 46 male subjects with unilateral chronic ACL-rupture performed isokinetic concentric (c), eccentric (e) quadriceps and hamstring muscle tests respectively at 60°/s. Normalized moments and H/Q ratios were calculated for peak moment (PM) and 30°, 40°, 50°, 60°, 70°, 80° knee flexion angles. Furthermore, we introduced single-to-arithmetic-mean (SAM) and single-to-root-mean-square (SRMS) muscle co-contraction ratios, calculating them for specific angles and different contraction repetitions. Normalized PM and 40° specific concentric quadriceps, concentric hamstring strength in the ACL-deficient knee were reduced significantly (P ≤ 0.05). Concentric angle-specific moments together with Qe/Qc ratios at 40° (d = 0.766 vs. d = 0.654) identify more obvious differences than peak values in ACL ruptured limbs. Furthermore, we found SRMS-QeQc deficits at 40° showed stronger effect than Qe/Qc ratios (d = 0.918 vs. d = 0.766), albeit other ratio differences remained basically the same effect size as the original H/Q ratios. All the newly defined SAM and SRMS indices could decrease variance. Overall, 40° knee moments and SAM/SRMS ratios might be new potential diagnosis indices for ACL rupture detection.

Functional performance 2-9 years after ACL reconstruction: cross-sectional comparison between athletes with bone-patellar tendon-bone, semitendinosus/gracilis and healthy controls

PURPOSE

The purpose of this cross-sectional study was to provide descriptive data on functional performance in men and women with ACLR, to compare bone-patellar tendon-bone (BPTB) with semitendinosus/gracilis (STG) within the same sex and to compare the ACLR subjects with healthy controls.

METHODS

Eligible participants comprised 100 men (43 % BPTB) and 84 women (41 % BPTB) after ACLR, of whom 30 men (STG n = 19; BPTB n = 11) and 18 women (STG n = 12; BPTB n = 6) were untraceable/not willing and 15 men (STG n = 9; BPTB n = 6) and 18 women (STG n = 12; BPTB n = 3) were not able to take part in the measurements because of injury. Besides men BPTB (n = 24), men STG (n = 27), women BPTB (n = 23) and women STG (n = 23), healthy men (n = 22) and women (n = 22) participated. Measurements consisted of questionnaires, isokinetic peak torque and endurance tests, a hop test battery and drop jump including video analysis.

RESULTS

Only the occurrence of dynamic knee valgus differed between ACLR and healthy subjects.

CONCLUSION

Two to nine years after ACLR, 16 % of athletes could not participate because of a lower extremity injury. In the remaining group, this study showed similar results for males and females with BPTB compared with STG. Also, similar results are found for quantity of movement comparing operated and healthy subjects. For quality of movement, only the occurrence of dynamic knee valgus in landing from a jump is higher in operated subjects compared with healthy controls. This supports the relevance of a focus on quality of movement as part of ACLR rehabilitation programmes and return to sports criteria.

LEVEL OF EVIDENCE

III.

Effects of Prophylactic Knee Bracing on Lower Limb Kinematics, Kinetics, and Energetics During Double-Leg Drop Landing at 2 Heights

BACKGROUND

Anterior cruciate ligament (ACL) injuries commonly occur during landing maneuvers. Prophylactic knee braces were introduced to reduce the risk of ACL injuries, but their effectiveness is debated.

HYPOTHESES

We hypothesized that bracing would improve biomechanical factors previously related to the risk of ACL injuries, such as increased hip and knee flexion angles at initial contact and at peak vertical ground-reaction force (GRF), increased ankle plantar flexion angles at initial contact, decreased peak GRFs, and decreased peak knee extension moment. We also hypothesized that bracing would increase the negative power and work of the hip joint and would decrease the negative power and work of the knee and ankle joints.

STUDY DESIGN

Controlled laboratory study.

METHODS

Three-dimensional motion and force plate data were collected from 8 female and 7 male recreational athletes performing double-leg drop landings from 0.30 m and 0.60 m with and without a prophylactic knee brace. GRFs, joint angles, moments, power, and work were calculated for each athlete with and without a knee brace.

RESULTS

Prophylactic knee bracing increased the hip flexion angle at peak GRF by 5.56° (P < .001), knee flexion angle at peak GRF by 4.75° (P = .001), and peak hip extension moment by 0.44 N·m/kg (P < .001). Bracing also increased the peak hip negative power by 4.89 W/kg (P = .002) and hip negative work by 0.14 J/kg (P = .001) but did not result in significant differences in the energetics of the knee and ankle. No differences in peak GRFs and peak knee extension moment were observed with bracing.

CONCLUSION

The application of a prophylactic knee brace resulted in improvements in important biomechanical factors associated with the risk of ACL injuries.

CLINICAL RELEVANCE

Prophylactic knee braces may help reduce the risk of noncontact knee injuries in recreational and professional athletes while playing sports. Further studies should investigate different types of prophylactic knee braces in conjunction with existing training interventions so that the sports medicine community can better assess the effectiveness of prophylactic knee bracing.

Individuals with chronic ankle instability exhibit altered landing knee kinematics: potential link with the mechanism of loading for the anterior cruciate ligament

BACKGROUND

Alterations in sagittal plane landing biomechanics in the lower extremity have been observed within the chronic ankle instability (CAI) population. Interestingly, a potential link between the risk of anterior cruciate ligament (ACL) injury and ankle sprain history has been proposed. However, it is not known if the observed biomechanical changes associated with CAI could mimic factors related to the mechanism of ACL injury. We investigated the influence of CAI on anterior tibial shear force (ATSF), lower extremity sagittal plane kinematics, and posterior ground reaction force (GRF) in a jump landing task.

METHODS

Nineteen participants with CAI and 19 healthy control participants performed a vertical stop jump. Peak ATSF was calculated during the first landing of the stop jump, with sagittal-plane kinematics and posterior GRF measured at peak ATSF. Independent t-tests, multiple linear regression, and Pearson bivariate correlation were used for statistical analysis.

FINDINGS

Participants with CAI demonstrated less knee flexion at peak ATSF compared to the controls (P=.026). No group-differences were found for peak ATSF or the other biomechanical variables. Knee flexion was moderately correlated with peak ATSF (r=-0.544, P=.008); however, the contributing factor that most explained the variance in ATSF was posterior GRF (R2=0.449; P=.002) in the CAI group.

INTERPRETATION

Our findings indicate that the CAI group may be exhibiting altered knee function during functional movement. Screening knee movement patterns in individuals with CAI may help develop preventative measures for future joint injury throughout the kinetic chain.

Asymmetrical loading demands associated with vertical jump landings in people with unilateral transtibial amputation

Loading symmetry during vertical jump landings between a person with amputation's intact and prosthetic limbs was assessed to determine the role of each limb in controlling the downward momentum of the center of mass during landing. Six participants with unilateral transtibial amputation (TTA) and ten nondisabled participants completed 10 maximal vertical jumps, of which the highest jump was analyzed. Contralateral symmetry was assessed through the Symmetry Index (SI), while symmetry at the group level was assessed through a Mann-Whitney U test. Participants with TTA performed quasi-unilateral landings onto the intact limbs, resulting from either the incapability of the prosthetic ankle to plantar flex or increased residual-limb knee and hip flexion. In the loading phase, the participants with TTA displayed reduced prosthetic-side peak vertical forces (p = 0.04) along with reduced prosthetic-side ankle range of motion (p < 0.001), extensor moments (p = 0.03), and negative work generated (p = 0.00). Individual asymmetries were evident in the peak vertical force magnitudes (SI = 51%-140%), duration from touchdown to peak vertical force (SI = 52%-157%), ankle joint angles at touchdown (SI = 100%-538%), ranges of motion (SI = 147%-200%), knee (SI = 66%-179%) and hip (SI = 87%-132%) extensor moments, and work done at the ankle (SI = 155%-199%) and hip (SI = 83%-204%). High peak forces (25.25 +/- 4.89 N·kg(-1) intact limb and 14.61 +/- 8.28 N·kg(-1) prosthetic limb) from significantly lower (p < 0.001) landing heights than the nondisabled participants indicate a potential injury risk associated with landing for people with TTA.

Do knee concentric and eccentric strength and sagittal-plane knee joint biomechanics differ between jumpers and non-jumpers in landing?

The purpose of this study was to investigate the differences of knee concentric and eccentric strength and impact related knee biomechanics between jumpers and non-jumpers during step-off landing tasks. Ten male college swimming athletes (non-jumpers) and 10 track and volleyball athletes (jumpers) were recruited to participate in two test sessions: a muscle strength testing session of concentric and eccentric extension for dominant knee joint at 60°/s and 180°/s and a landing testing session. The participants performed five trials of step-off landing in each of four conditions: soft and stiff landing from 0.4m and 0.6m landing heights. The three-dimensional kinematics and ground reaction force were recorded simultaneously during step-off landing conditions. The results showed that the jumpers had significantly greater peak knee eccentric extension and concentric flexion torques compared to the non-jumpers. No significant group effects were found for peak vertical ground reaction force and knee range of motion during landing. The jumpers had significantly greater knee contact flexion angle, maximum knee flexion angle and initial knee extension moment compared to the non-jumpers. These results suggest that these athletes adopted a favorable impact attenuation strategy that is related to the greater knee eccentric muscle strength and training.

Influence of lean body mass and strength on landing energetics

PURPOSE

Less lean body mass may limit one's ability to produce adequate muscle forces to safely control landing from a jump, thus increasing the risk for injury. The primary objective of this study was to determine the effect of lower extremity lean mass (LELM) and eccentric muscle strength on lower extremity energy absorption (EA) during a drop jump landing.

METHODS

Seventy athletic subjects (35 men and 35 women) were measured for LELM with dual-energy x-ray absorptiometry, maximal eccentric strength of the quadriceps (QuadECC) and hamstrings (HamECC), and lower extremity joint energetics during the initial landing of a drop jump. A mediation analysis examined the extent to which LELM predicted EA at each lower extremity joint (EAHIP, EAKNEE, and EAANK) and subsequently whether these relationships were mediated by each subject's maximal eccentric strength capabilities.

RESULTS

LELM was a significant predictor of EAKNEE (R = 0.22, P < 0.01) in females but not in males (R = 0.03, P = 0.16). In females, QuadECC was a significant mediator of the effect of LELM on EA at the knee (ab = 179.72, 95% confidence interval [CI] = 10.43-423.42) and ankle (ab = 1.71, 95% CI = [0.16, 3.94]), whereas HamECC was a significant mediator of the relationship between LELM and EAHIP (ab = 4.89, 95% CI = 2.05-8.40). No significant relationships were observed in males.

CONCLUSIONS

LELM was a significant factor in energetic capabilities for females but not males. For females, this relationship was evident secondary to the stronger underlying relationship between maximal strength and EA. Thus, the maximal eccentric strength capabilities may be a more important determinant of energetic behaviors compared with the available quantity of lean mass alone. More work is needed to investigate these relationships and to reveal the underlying sex-specific mechanisms that determine EA capabilities.

Assessment of functional performance after anterior cruciate ligament reconstruction: a systematic review of measurement procedures

PURPOSE

The purpose of this systematic review was to identify the measurements that are used in clinical practice to assess the quantity and quality of functional performance in men and women more than 2 years after ACL reconstruction with bone patellar-tendon bone (BPTB) or semitendinosus/gracilis (STG) graft.

METHODS

A systematic literature search was performed in Medline (Pubmed), EMBASE (OVID), the Cochrane Library and PEDro to identify relevant articles from 1990 up to 2010. Articles were included if they described functional performance after BPTB or STG reconstruction and had a follow-up of more than 2 years. Two authors screened the selected articles for title, abstract and full-text in accordance with predefined inclusion and exclusion criteria. The methodological quality of all articles was assessed by checklists of the Cochrane Library by two authors. Only the articles with good methodological quality were considered for further analysis.

RESULTS

A total of 27 studies were included by full-text. According to their methodological quality six were rated as good. Different authors used different study designs for muscle testing which led to different outcomes that could not be compared. Besides strength, a single-leg hop for distance was used as a measurement for quantity of functional performance. No measurements for quality of functional performance were reported.

CONCLUSIONS

Measurement of functional performance more than 2 years after ACL reconstruction consists of concentric or isometric strength, the single-leg hop for distance or a combination. The Limb Symmetry Index is used as the main outcome parameter to compare the involved leg with the uninvolved. In all studies the results of men and woman are combined. Based on our findings and previous studies that discussed additional important parameters a more extensive test battery to assess functional performance is suggested.

Quadriceps and hamstrings coactivation during common therapeutic exercises

CONTEXT

Anterior tibial shear force and knee valgus moment increase anterior cruciate ligament (ACL) loading. Muscle coactivation of the quadriceps and hamstrings influences anterior tibial shear force and knee valgus moment, thus potentially influencing ACL loading and injury risk. Therefore, identifying exercises that facilitate balanced activation of the quadriceps and hamstrings might be beneficial in ACL injury rehabilitation and prevention.

OBJECTIVE

To quantify and compare quadriceps with hamstrings coactivation electromyographic (EMG) ratios during commonly used closed kinetic chain exercises.

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty-seven healthy, physically active volunteers (12 men, 15 women; age = 22.1 ± 3.1 years, height = 171.4 ± 10 cm, mass = 72.4 ± 16.7 kg).

INTERVENTION(S)

Participants completed 9 separate closed chain therapeutic exercises in a randomized order.

MAIN OUTCOME MEASURE(S)

Surface electromyography quantified the activity level of the vastus medialis (VM), vastus lateralis (VL), medial hamstrings (MH), and biceps femoris (BF) muscles. The quadriceps-to-hamstrings (Q:H) coactivation ratio was computed as the sum of average quadriceps (VM, VL) EMG amplitude divided by the sum of average hamstrings (MH, BF) EMG amplitude for each trial. We used repeated-measures analyses of variance to compare Q:H ratios and individual muscle contributions across exercises (α = .05), then used post hoc Tukey analyses.

RESULTS

We observed a main effect for exercise (F(3,79) = 22.6, P< .001). The post hoc Tukey analyses revealed smaller Q:H ratios during the single-limb dead lift (2.87 ± 1.77) than the single-limb squat (5.52 ± 2.89) exercise. The largest Q:H ratios were observed during the transverse-lunge (7.78 ± 5.51, P< .001), lateral-lunge (9.30 ± 5.53, P< .001), and forward-lunge (9.70 ± 5.90, P< .001) exercises.

CONCLUSIONS

The most balanced (smallest) coactivation ratios were observed during the single-limb dead-lift, lateral-hop, transverse-hop, and lateral band-walk exercises. These exercises potentially could facilitate balanced activation in ACL rehabilitation and injury-prevention programs. They also could be used in postinjury rehabilitation programs in a safe and progressive manner.