scholarly journals The Relationship Between 2-Dimensional Knee-Valgus Angles During Single-Leg Squat, Single-Leg-Land, and Drop-Jump Screening Tests

2017 ◽  
Vol 26 (1) ◽  
pp. 72-77 ◽  
Author(s):  
Allan Munro ◽  
Lee Herrington ◽  
Paul Comfort
Keyword(s):  
Outcome Measures ◽  
Injury Risk ◽  
Female Athletes ◽  
Screening Tests ◽  
Knee Valgus ◽  
Drop Jump ◽  
Risk Of Injury ◽  
National League ◽  
Single Leg Squat ◽  
The Relationship

Context:Injuries to the anterior cruciate ligament (ACL) and patellofemoral joint (PFJ) are a significant problem in female athletes. A number of screening tasks have been used in the literature to identify those at greatest risk of injury. To date, no study has examined the relationship in 2-dimensional (2D) knee valgus between common screening tasks to determine whether individuals exhibit similar movement patterns across tasks.Objective:To establish whether frontal-plane projection angle (FPPA) during the single-leg squat (SLS), single-leg land (SLL), and drop jump (DJ) are related.Design:Cross-sectional study.Setting:University laboratory.Participants:52 national-league female football players and 36 national-league female basketball players.Main Outcome Measures:2D FPPA during the SLS, SLL, and DJ screening tasks.Results:Significant correlations were found between tasks. FPPA in the SLS was significantly correlated with SLL (r = .52) and DJ (r = .30), whereas FPPA in the SLL was also significantly correlated to DJ (r = .33). FPPA was significantly greater in the SLS than in the SLL (P < .001) and DJ (P < .001) and in the SLL than in the DJ (P < .001).Conclusion:The results showed that 2D FPPA is correlated across the SLS, SLL, and DJ tasks. However, significantly greater FPPA values in the unilateral tasks suggest that the DJ may not identify risk of injury in sports where primary injury mechanisms are during unilateral loading tasks. Therefore, it is recommended that both unilateral and bilateral tasks be included when screening for ACL and PFJ injury risk.

scholarly journals The Relationship between Dynamic Balance and Jumping Tests among Adolescent Amateur Rugby Players. A Preliminary Study

2021 ◽  
Vol 18 (1) ◽  
pp. 312
Author(s):  
Bartosz Wilczyński ◽  
Jakub Hinca ◽  
Daniel Ślęzak ◽  
Katarzyna Zorena
Keyword(s):  
Injury Risk ◽  
Dynamic Balance ◽  
Study Data ◽  
Balance Test ◽  
Risk Of Injury ◽  
Counter Movement Jump ◽  
Increased Risk ◽  
Positive Correlations ◽  
The Relationship ◽  
Rugby Players

Rugby is a demanding contact sport. In light of research, poor balance, reduced jumping ability, muscle strength, and incorrect landing patterns might contribute to the increased risk of injury in athletes. Investigating the relationship between tests assessing these abilities might not only allow for the skillful programming of preventive training but also helps in assessing the risk of injury to athletes. Thus, the main purpose of this study was to investigate the relationship between dynamic balance, vertical and horizontal jumps, and jump-landings movement patterns. Thirty-one healthy amateur adolescent rugby players (age: 14.3 ± 1.6 years, height 171.4 ± 9.7 cm, body mass 80 ± 26 kg) participated in the study. Data were collected by the Y-balance Test (YBT), Counter Movement Jump (CMJ), Single Leg Hop for Distance (SLHD), and Landing Error Score System (LESS). Significant positive correlations were found between SLHD both legs (SLHDb) and YBT Composite both legs (COMb) (r = 0.51, p = 0.0037) and between SLHDb and CMJ (r = 0.72, p < 0.0001). A relationship was also observed between the CMJ and YBT COMb test (r = 0.51, p = 0.006). Moderate positive correlations were found between the dominant legs in SLHD and the posterolateral (r = 0.40, p = 0.027), posteromedial (r = 0.43, p = 0.014), and composite (r = 0.48, p = 0.006) directions of the YBT. These results indicate that variables that are dependent on each other can support in the assessment of injury-risk and in enhancing sports performance of young athletes.

scholarly journals SINGLE LEG SQUAT COMPENSATIONS ASSOCIATE WITH SOFTBALL PITCHING PATHOMECHANICS IN ADOLESCENT SOFTBALL PITCHERS

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0006
Author(s):  
Gretchen D. Oliver ◽  
Kenzie B. Friesen ◽  
Regan E. Shaw ◽  
David Shannon ◽  
Jeffrey Dugas ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Knee Valgus ◽  
Trunk Rotation ◽  
Lateral Flexion ◽  
Trunk Flexion ◽  
Backward Elimination ◽  
Potential Risk Factors ◽  
Single Leg Squat ◽  
Tracking Device ◽  
The Relationship

Background: Softball pitchers have an eminent propensity for injury due to the high repetition and ballistic nature of the pitch. As such, trunk pathomechanics during pitching have been associated with upper extremity pain. The single leg squat (SLS) is a simple diagnostic tool used to examine LPHC and trunk stability. Research shows a lack of LPHC stability is often associated with altered pitching mechanics consequently increasing pain and injury susceptibility. Hypothesis/Purpose: The purpose of this study was to examine the relationship between trunk compensatory kinematics during the SLS and kinematics during foot contact of the windmill pitch. The authors hypothesized there would be a relationship between SLS compensations and pitch kinematics previously associated with injury. In using a simple clinical assessment such as the SLS, athletes, coaches, parents, and clinicians can identify potential risk factors that may predispose the athlete to injurious movement patterns. Methods: Fifty-five youth and high school softball pitchers (12.6±2.2 years, 160.0±11.0 cm, 60.8±15.5 kg) were recruited to participate. Kinematic data were collected at 100Hz using an electromagnetic tracking device. Participants were asked to complete a SLS on their stride leg (contralateral to their throwing arm), then throw 3 fastballs at maximal effort. Values of trunk flexion, trunk lateral flexion, and trunk rotation at peak depth of the SLS were used as the dependent variables in three separate backward elimination regression analyses. Independent variables examined at foot contact of the pitch included: trunk flexion, trunk lateral flexion, trunk rotation, center of mass, stride length, and stride knee valgus. Results: The SLS trunk rotation regression, F(1,56) = 4.980, p = .030, revealed trunk flexion significantly predicted SLS trunk rotation (SE = .068, t = 2.232, p = .030) and explained approximately 7% of variance (Adj. R2 = .066). The SLS trunk flexion regression, F(1,56) = 5.755, p = .020, revealed stride knee valgus significantly predicted SLS trunk flexion (SE = .256, t = 2.399, p = .020) and explained approximately 8% of variance (Adj. R2 = .078). Conclusion/Significance: Additional trunk rotation and trunk flexion at peak depth of the SLS indicate increased knee valgus and trunk flexion at foot contact of the pitch, both of which suggest poor LPHC stability, may increase the potential for injury. Athletes, coaches and clinicians should acknowledge the risk of poor LPHC in softball pitching and implement exercises to improve LPHC stability in effort to decrease pitching pathomechanics and associated pain.

Hip and ankle strength and range of motion in female soccer players with dynamic knee valgus

2021 ◽  
pp. 1-6
Author(s):  
Young Jin Jo ◽  
Young Kyun Kim
Keyword(s):  
Range Of Motion ◽  
Female Athletes ◽  
External Rotation ◽  
Preventive Measure ◽  
Control Group ◽  
Knee Valgus ◽  
Strength Ratio ◽  
Flexion Extension ◽  
Hip Abduction ◽  
Single Leg Squat

BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p< 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p< 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p< 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation.

Preliminary Evaluation of Knee Kinetics in Female Athletes on Hormonal Contraceptives

2019 ◽  
Vol 41 (02) ◽  
pp. 113-118
Author(s):  
Gabrielle Gilmer ◽  
Gretchen D. Oliver
Keyword(s):  
Injury Risk ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Acl Injury ◽  
Hormonal Contraceptives ◽  
Preliminary Evaluation ◽  
Knee Valgus ◽  
Time Points ◽  
Acl Injury Risk

AbstractRecently, an emphasis has been placed on understanding how ovarian sex hormones and hormonal contraceptives affect risk for anterior cruciate ligament (ACL) injury. The literature presents large discrepancies in whether or not hormonal contraceptives affect ACL injury risk; therefore, the purpose of this study was to evaluate whether vertical ground reaction force (GRF) and knee valgus force are different between athletes who do and do not use hormonal contraceptives. Twenty-two female athletes volunteered to participate and were divided into two groups based on their answers to a health history questionnaire: those who use hormonal contraceptives and those who do not. Participants performed a drop vertical jump (DVJ) and single leg crossover dropdown (SCD) at two different time points in their menstrual cycle (pre-ovulatory phase and mid-luteal phase). Kinetic data were collected at 1000 Hz. Independent samples t-tests revealed no significant differences between groups in vertical GRF and knee valgus force at both time points. Findings from this study suggest that hormonal contraceptives do not elicit detectable changes in vertical GRF and knee valgus force. Ultimately, this calls for further studies on the relationship between hormones and ACL injury risk and physicians to consider hormonal screening in addition to neuromuscular and biomechanical screening.

Single Leg Squat Test and Its Relationship to Dynamic Knee Valgus and Injury Risk Screening

PM&R ◽  
2014 ◽  
Vol 7 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Viviane Ugalde ◽  
Chuck Brockman ◽  
Zach Bailowitz ◽  
Christine D. Pollard
Keyword(s):  
Injury Risk ◽  
Knee Valgus ◽  
Risk Screening ◽  
Single Leg Squat

Knee Valgus during Drop Jumps in National Collegiate Athletic Association Division I Female Athletes

2007 ◽  
Vol 36 (2) ◽  
pp. 285-289 ◽  
Author(s):  
Michael Joseph ◽  
David Tiberio ◽  
Jennifer L. Baird ◽  
Thomas H. Trojian ◽  
Jeffrey M. Anderson ◽  
...  
Keyword(s):  
National Collegiate Athletic Association ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Division I ◽  
Ligament Injury ◽  
Initial Contact ◽  
Knee Valgus ◽  
Drop Jump ◽  
Maximum Angle ◽  
Anterior Cruciate

Background Female athletes land from a jump with greater knee valgus and ankle pronation/eversion. Excessive valgus and pronation have been linked to risk of anterior cruciate ligament injury. A medially posted orthosis decreases component motions of knee valgus such as foot pronation/eversion and tibial internal rotation. Hypothesis We hypothesized a medial post would decrease knee valgus and ankle pronation/eversion during drop-jump landings in NCAA-I female athletes. Study Design Controlled laboratory study. Methods Knee and ankle 3-dimensional kinematics were measured using high-speed motion capture in 10 National Collegiate Athletic Association Division I female athletes during a drop-jump landing with and without a medial post. Analysis of variance was used to determine differences in posting condition, t tests were used to determine dominant-nondominant differences, and the Pearson correlation coefficient was used to determine relationships between variables. Results Significant differences were found for all measures in the posted condition. A medial post decreased knee valgus at initial contact (1.24°, P< .01) and maximum angle (1.21 °, P< .01). The post also decreased ankle pronation/eversion at initial contact (0.77°, P < .01) and maximum angle (0.95°, P = .039). Conclusion The authors have demonstrated a significant decrease in knee valgus and ankle pronation/eversion during a drop jump with a medial post placed in the athletes’ shoes. Clinical Relevance A medial post may be a potential means to decrease risk of anterior cruciate ligament injury.

The Relationship between Serum Relaxin Concentrations and Knee Valgus

2020 ◽  
Vol 41 (03) ◽  
pp. 182-188
Author(s):  
Gabrielle G. Gilmer ◽  
Michael D. Roberts ◽  
Gretchen D. Oliver
Keyword(s):  
Anterior Cruciate Ligament ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Vertical Jump ◽  
Ligament Injury ◽  
Knee Valgus ◽  
Clinical Tests ◽  
Anterior Cruciate Ligament Injuries ◽  
Anterior Cruciate ◽  
The Relationship

AbstractFemale athletes are at an elevated risk for tearing their anterior cruciate ligament, compared to their male counterparts. Though injury screening clinical tests and neuromuscular training programs have been widely implemented, injury rates remain high among female athletes. The purpose of this study was to examine the relationship between serum relaxin concentrations and knee valgus during three clinical tests (single leg squat, drop vertical jump, and single leg crossover dropdown). Twenty-two female athletes volunteered. Participants were scheduled for collection during the mid-luteal phase, when serum relaxin concentrations are known to be measurable. Blood samples were collected, and serum relaxin concentrations were quantified. Kinematic data were collected while participants performed the three clinical tests. Regression analyses revealed statistically significant relationships between serum relaxin concentrations and knee valgus throughout all tests. These findings suggest that serum relaxin concentrations and knee valgus are not independent of each other and more holistic approaches may be necessary to truly map out the risk for injury and ultimately reduce the rate of anterior cruciate ligament injuries. Thus, concluding that knee valgus, a highly utilized modifiable biomechanical risk factor, and relaxin, a hormone that has been associated with anterior cruciate ligament injury in female athletes, are related to each other.

Weak Hip Strength Increases Dynamic Knee Valgus in Single-Leg Tasks of Collegiate Female Athletes

2021 ◽  
pp. 1-4
Author(s):  
Kyndell R. Crowell ◽  
Ryan D. Nokes ◽  
Nicole L. Cosby
Keyword(s):  
Female Athletes ◽  
External Rotation ◽  
Common Factor ◽  
Knee Valgus ◽  
Bottom Line ◽  
Level Of Evidence ◽  
Hip Strength ◽  
Risk Of Injury ◽  
Increased Risk ◽  
Collegiate Female Athletes

Clinical Scenario: Dynamic knee valgus (DKV) is a mechanical alteration in the knee that leads to increased risk of injury. Weakness of hip musculature in hip abduction (HABD), extension (HEXT), and external rotation (HER) may contribute to increased DKV in single-leg landing tasks. Focused Clinical Question: Is decreased hip strength associated with an increase in DKV during a single-leg landing task in collegiate female athletes? Summary of Key Findings: Three studies were included: One randomized control trial (RCT), one cohort study, and one case-control. All three studies found that decreases in HABD and HER strength contributed to increased DKV during single-leg landing tasks. One study also found that the hip extensors contribute to controlling hip adduction, a common factor in many mechanisms of injuries. These three studies recommended strengthening HABD, HEXT, and HER to decrease DKV and reduce the risk of injury at the knee. Clinical Bottom Line: Weak HABD, HEXT, and HER contribute to increased DKV in college female athletes, but strengthening HABD, HEXT, and HER can lead to decreases in DKV and, overall, reduce the risk of injury at the knee. Strength of Recommendation: These articles were graded with a level of evidence of III or higher, giving a grade of B strength of recommendation that weak HABD, HEXT, and HER are associated with increased DKV in collegiate female athletes.

scholarly journals SEX-SPECIFIC ENERGY ABSORPTION STRATEGIES DURING UNANTICIPATED SINGLE-LEG LANDINGS IN ADOLESCENTS: IMPLICATIONS FOR KNEE INJURIES

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0023
Author(s):  
Nicholas J. Romanchuk ◽  
Michael J. Del Bel ◽  
Daniel L. Benoit
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Joint Strength ◽  
Female Athletes ◽  
Plantar Flexion ◽  
Adolescent Male ◽  
Drop Jump ◽  
Joint Power ◽  
Specific Energy Absorption ◽  
The Relationship

Background: The vast majority of ACL injuries in adolescents occur during non-contact injuries, in particular single-leg landings. The magnitude of energy absorption about each joint during theses landings influences the internal and external forces acting on the joints of the lower extremity. Understanding the biomechanics of landing in adolescent male and female athletes may provide insight into these non-contact injury mechanisms. Hypothesis/Purpose: This study set out to identify sex-specific energy absorption strategies during single-leg landing and determine the relationship between joint strength and the observed strategies. To better represent real-world conditions, we developed a novel unanticipated drop-jump landing protocol for this population. Methods: Thirty-one healthy youth athletes completed unanticipated single-leg drop-jump landings on their dominant limb. Kinematics and lower-limb contributions to energy absorption were calculated over the landing phase for each jump. Independent t-tests as well as Mann-Whitney U tests determined the presence of statistical differences between sexes. Pearson and Spearman correlation coefficients determined the relationship between isometric joint strength and the observed kinematics and energy absorption. Results: Females participants absorbed a larger proportion of the landing forces at the ankle and smaller proportion at the hip compared to males. Females also reached larger peak negative joint power in their knee and ankle. Both hip extension and ankle plantar flexion strength were correlated with greater spine flexion and less pelvic flexion. Conclusion: Females adopted an energy absorption strategy which utilized distal joints to absorb a larger portion of the landing forces and tended to absorb the forces later relative to males. A greater reliance on the distal joints is related to reduced hip strength and may increase the risk for sustaining an ACL injury.

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