scholarly journals Inter-Segmental Coordination during a Unilateral 180° Jump in Elite Rugby Players: Implications for Prospective Identification of Injuries

2020 ◽  
Vol 10 (2) ◽  
pp. 427 ◽  
Author(s):  
Kellen T. Krajewski ◽  
Carla McCabe ◽  
Aaron M. Sinnott ◽  
Gavin L. Moir ◽  
Hugh S. Lamont ◽  
...  
Keyword(s):  
Injury Risk ◽  
Assessment Tool ◽  
Knee Kinematics ◽  
Assessment Tools ◽  
Peak Knee ◽  
Knee Abduction ◽  
Current Assessment ◽  
Segmental Coordination ◽  
Rotational Method ◽  
Rugby Players

Musculoskeletal injuries often occur during the execution of dynamic sporting tasks that involve rotation. The prescription of appropriate prevention strategies of musculoskeletal injury relies on assessments to identify risk, but current assessment tools focus on uniplanar movements. The purpose of this paper is to demonstrate the utility of the unilateral 180° jump as a potential assessment tool for injury risk in the lower body by (1) providing descriptive kinematics of the knee, thigh, and pelvis (2) conducting inter-segmental coordination analysis, and (3) comparing the knee kinematics between the dominant and non-dominant limb (NDL) during the loading (LOP) and landing phase (LAP). Elite rugby players completed one session, performing five 180° unilateral jumps on each limb while collecting kinematic data. Independent t-tests were used to compare peak angles of DL and NDL. Continuous Relative Phase (CRP) plots were constructed for thorax and pelvis in the transverse plane. At the loading phase, the non-dominant limb had greater peak knee abduction (ABD) (p = 0.01). At the landing phase, the dominant limb had greater peak knee adduction (ADD) (p = 0.05). At the landing phase, the non-dominant limb had greater peak knee ABD (p = 0.01). CRP plots indicate participants can utilize a thorax-led, pelvis-led, or synchronized rotational method. Bilateral asymmetries were observed, indicated by significant differences in the bilateral landing phase peak ADD/ABD, which is of particular interest considering all participants were healthy. Therefore, additional research is needed to determine thresholds for injury risk during rotational tasks.

scholarly journals NEURAL ACTIVITY AND LANDING BIOMECHANICS: EXPLORING THE RELATIONSHIPS BETWEEN THE BRAIN, BODY, AND ACL INJURY-RISK

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0015
Author(s):  
Cody R. Criss ◽  
Dustin R. Grooms ◽  
Jed A. Diekfuss ◽  
Manish Anand ◽  
Alexis B. Slutsky-Ganesh ◽  
...  
Keyword(s):  
Neural Activity ◽  
Injury Risk ◽  
Neural Control ◽  
Motor Coordination ◽  
Cruciate Ligament ◽  
Vertical Jump ◽  
Frontal Plane ◽  
Peak Knee ◽  
Knee Abduction ◽  
Drop Vertical Jump

Background: Anterior cruciate ligament (ACL) injuries predominantly occur via non-contact mechanisms, secondary to motor coordination errors resulting in aberrant frontal plane knee loads that exceed the thresholds of ligament integrity. However, central nervous system processing underlying high injury-risk motor coordination errors remain unknown, limiting the optimization of current injury reduction strategies. Purpose: To evaluate the relationships between brain activity during motor tasks with injury-risk loading during a drop vertical jump. Methods: Thirty female high school soccer players (16.10 ± 0.87 years, 165.10 ± 4.64 cm, 63.43 ± 8.80 kg) were evaluated with 3D biomechanics during a standardized drop vertical jump from a 30 cm box and peak knee abduction moment was extracted as the injury-risk variable of interest. A neuroimaging session to capture neural activity (via blood-oxygen-level-dependent signal) was then completed which consisted of 4 blocks of 30 seconds of repeated bilateral leg press action paced to a metronome beat of 1.2 Hz with 30 seconds rest between blocks. Knee abduction moment was evaluated relative to neural activity to identify potential neural contributors to injury-risk. Results: There was a direct relationship between increased landing knee abduction moment and increased neural activation within regions corresponding to the lingual gyrus, intracalcarine cortex, posterior cingulate cortex, and precuneus (r2= 0.68, p corrected < .05, z max > 3.1; Table 1 & Figure 1). Conclusion: Elevated activity in regions that integrate sensory, spatial, and attentional information may contribute to elevated frontal plane knee loads during landing. Interestingly, a similar activation pattern related to high-risk landing mechanics has been found in those following injury, indicating that predisposing factors to injury may be accentuated by injury or that modern rehabilitation does not recover prospective neural control deficits. These data uncover a potentially novel brain marker that could guide the discovery of neural-therapeutic targets that reduce injury risk beyond current prevention methods. [Table: see text][Figure: see text]

Optimizing Whole-Body Kinematics During Single-Leg Jump Landing to Reduce Peak Abduction/Adduction and Internal Rotation Knee Moments: Implications for Anterior Cruciate Ligament Injury Risk

2021 ◽  
pp. 1-8
Author(s):  
Dhruv Gupta ◽  
Jeffrey A. Reinbolt ◽  
Cyril J. Donnelly
Keyword(s):  
Internal Rotation ◽  
Injury Risk ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Whole Body ◽  
Jump Landing ◽  
Peak Knee ◽  
Knee Abduction ◽  
Acl Injury Risk ◽  
Anterior Cruciate

Knee abduction/adduction moment and knee internal rotation moment are known surrogate measures of anterior cruciate ligament (ACL) load during tasks like sidestepping and single-leg landing. Previous experimental literature has shown that a variety of kinematic strategies are associated or correlated with ACL injury risk; however, the optimal kinematic strategies needed to reduce peak knee moments and ACL injury are not well understood. To understand the complex, multifaceted kinematic factors underpinning ACL injury risk and to optimize kinematics to prevent the ACL injury, a musculoskeletal modeling and simulation experimental design was used. A 14-segment, 37-degree-of-freedom, dynamically consistent skeletal model driven by force/torque actuators was used to simulate whole-body single-leg jump landing kinematics. Using the residual reduction algorithm in OpenSim, whole-body kinematics were optimized to reduce the peak knee abduction/adduction and internal/external rotation moments simultaneously. This optimization was repeated across 30 single-leg jump landing trials from 10 participants. The general optimal kinematic strategy was to bring the knee to a more neutral alignment in the transverse plane and frontal plane (featured by reduced hip adduction angle and increased knee adduction angle). This optimized whole-body kinematic strategy significantly reduced the peak knee abduction/adduction and internal rotation moments, transferring most of the knee load to the hip.

scholarly journals Association of Quadriceps and Hamstrings Cocontraction Patterns With Knee Joint Loading

2009 ◽  
Vol 44 (3) ◽  
pp. 256-263 ◽  
Author(s):  
Riann M. Palmieri-Smith ◽  
Scott G. McLean ◽  
James A. Ashton-Miller ◽  
Edward M. Wojtys
Keyword(s):  
Lower Extremity ◽  
Injury Risk ◽  
Female Athletes ◽  
Vastus Lateralis ◽  
Cruciate Ligament ◽  
Neuromuscular Control ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Peak Knee ◽  
Knee Abduction

Abstract Context: Sex differences in neuromuscular control of the lower extremity have been identified as a potential cause for the greater incidence of anterior cruciate ligament (ACL) injuries in female athletes compared with male athletes. Women tend to land in greater knee valgus with higher abduction loads than men. Because knee abduction loads increase ACL strain, the inability to minimize these loads may lead to ACL failure. Objective: To investigate the activation patterns of the quadriceps and hamstrings muscles with respect to the peak knee abduction moment. Design: Cross-sectional study. Setting: Neuromuscular research laboratory. Patients or Other Participants: Twenty-one recreationally active adults (11 women, 10 men). Main Outcome Measure(s): Volunteers performed 3 trials of a 100-cm forward hop. During the hop task, we recorded surface electromyographic data from the medial and lateral hamstrings and quadriceps and recorded lower extremity kinematics and kinetics. Lateral and medial quadriceps-to-hamstrings (Q∶H) cocontraction indices, the ratio of medial-to-lateral Q∶H cocontraction, normalized root mean square electromyographic data for medial and lateral quadriceps and hamstrings, and peak knee abduction moment were calculated and used in data analyses. Results: Overall cocontraction was lower in women than in men, whereas activation was lower in the medial than in the lateral musculature in both sexes (P &lt; .05). The medial Q∶H cocontraction index (R2  =  0.792) accounted for a significant portion of the variance in the peak knee abduction moment in women (P  =  .001). Women demonstrated less activation in the vastus medialis than in the vastus lateralis (P  =  .49) and less activation in the medial hamstrings than in the lateral hamstrings (P  =  .01). Conclusions: Medial-to-lateral Q∶H cocontraction appears to be unbalanced in women, which may limit their ability to resist abduction loads. Because higher abduction loads increase strain on the ACL, restoring medial-to-lateral Q∶H cocontraction balance in women may help reduce ACL injury risk.

scholarly journals Glucocorticoid-Induced Osteoporosis: The Potential Role of Romosozumab

2020 ◽  
Vol 20 (02) ◽  
pp. 71-79
Author(s):  
Jacqueline So ◽  
Chi Chiu Mok
Keyword(s):  
Potential Role ◽  
Assessment Tool ◽  
Early Recognition ◽  
Assessment Tools ◽  
Estimation Formula ◽  
Fracture Risk Assessment Tool ◽  
Current Therapies ◽  
Current Assessment ◽  
Dose Dependent

Glucocorticoid (GC)-induced osteoporosis (GIOP) is a major problem in patients with rheumatic diseases. The deleterious effect of GC on bone turnover is rapid and dose-dependent, with a predilection on the trabecular bone, resulting in vertebral fractures. Early recognition and prompt treatment of GIOP helps prevent bone loss and reduce fractures. There are pitfalls in current assessment tools for GIOP by dual-energy X-ray absorptiometry (DXA) and fracture risk assessment tool (FRAX) estimation formula. In this review, we evaluate different assessment methods for GIOP and summarize current therapies of GIOP, including the antiresorptive and anabolic agents. The potential role of newer anti-osteoporosis agent romosozumab, an anti-sclerostin monoclonal antibody, is also discussed.

The Effect of Abdominal Muscle Activation Techniques on Trunk and Lower Limb Mechanics During the Single-Leg Squat Task in Females

2018 ◽  
Vol 27 (5) ◽  
pp. 438-444
Author(s):  
Lukas D. Linde ◽  
Jessica Archibald ◽  
Eve C. Lampert ◽  
John Z. Srbely
Keyword(s):  
Lower Limb ◽  
Injury Risk ◽  
Muscle Activation ◽  
Acl Injury ◽  
Abdominal Muscle ◽  
Abduction Angle ◽  
Peak Knee ◽  
Knee Abduction ◽  
Acl Injury Risk ◽  
Healthy Females

Context: Females suffer 4 to 6 times more noncontact anterior cruciate ligament (ACL) injuries than males due to neuromuscular control deficits of the hip musculature leading to increases in hip adduction angle, knee abduction angle, and knee abduction moment during dynamic tasks such as single-leg squats. Lateral trunk displacement has been further related to ACL injury risk in females, leading to the incorporation of core strength/stability exercises in ACL preventative training programs. However, the direct mechanism relating lateral trunk displacement and lower limb ACL risk factors is not well established. Objective: To assess the relationship between lateral trunk displacement and lower limb measures of ACL injury risk by altering trunk control through abdominal activation techniques during single-leg squats in healthy females. Design: Interventional study setting: movement and posture laboratory. Participants: A total of 13 healthy females (21.3 [0.88] y, 1.68 [0.07] m, and 58.27 [5.46] kg). Intervention: Trunk position and lower limb kinematics were recorded using an optoelectric motion capture system during single-leg squats under differing conditions of abdominal muscle activation (abdominal hollowing, abdominal bracing, and control), confirmed using surface electromyography. Main Outcome Measures: Lateral trunk displacement, peak hip adduction angle, peak knee abduction angle/moment, and average muscle activity from bilateral internal oblique, external oblique, and erector spinae muscles. Results: No differences were observed for peak lateral trunk displacement, peak hip adduction angle, or peak knee abduction angle/moment. Abdominal hollowing and bracing elicited greater muscle activation than the control condition, and bracing was greater than hollowing in 4 of 6 muscles recorded. Conclusion: The lack of reduction in trunk, hip, and knee measures of ACL injury risk during abdominal hollowing and bracing suggests that these techniques alone may provide minimal benefit in ACL injury prevention training.

Effect of Sex and Ankle Brace Design on Knee Biomechanics During a Single-Leg Cut

2020 ◽  
Vol 48 (6) ◽  
pp. 1496-1504
Author(s):  
Wyatt D. Ihmels ◽  
Kayla D. Seymore ◽  
Tyler N. Brown
Keyword(s):  
Internal Rotation ◽  
Repeated Measures ◽  
Injury Risk ◽  
Abduction Angle ◽  
Knee Biomechanics ◽  
Ankle Inversion ◽  
Ankle Brace ◽  
Peak Knee ◽  
Knee Abduction ◽  
And Control

Background: Despite success at preventing ankle sprain, prophylactics that restrict ankle plantarflexion motion may produce deleterious knee biomechanics and increase injury risk. Purpose: To determine if ankle prophylactics that restrict plantar- and dorsiflexion motion produce changes in knee biomechanics during a single-leg cut and whether those changes differ between sexes. Study Design: Controlled laboratory study. Methods: A total of 17 male and 17 female participants performed a single-leg cut with 4 conditions: Ankle Roll Guard (ARG), lace-up brace, nonelastic tape, and an unbraced control. Peak stance knee flexion, abduction, and internal rotation joint angle and moment; total knee reaction moment (TKM) and its components (sagittal, frontal, and transverse); and ankle plantarflexion and inversion range of motion (ROM) and peak stance joint moments were tested with a repeated measures analysis of variance to determine the main effect and interaction of condition and sex. Results: Brace and tape restricted plantarflexion ROM as compared with ARG and control (all P < .001). With the brace, women had increased peak knee abduction angle versus ARG ( P = .012) and control ( P = .009), and men had decreased peak knee internal rotation moment as compared with ARG ( P = .032), control ( P = .006), and tape ( P = .003). Although the restrictive tape decreased inversion ROM when compared with ARG ( P = .004) and brace ( P = .017), it did not change knee biomechanics. Neither brace nor tape produced significant changes in TKM or components, yet sagittal TKM increased with ARG versus control ( P = .016). Women exhibited less ankle inversion ROM ( P = .003) and moment ( P = .049) than men, while men exhibited significantly greater frontal TKM ( P = .022) and knee internal rotation moment with the ARG ( P = .029), control ( P = .007), and tape ( P = .016). Conclusion: Prophylactics that restrict ankle plantarflexion motion may elicit knee biomechanical changes during a single-leg cut, but these changes may depend on prophylactic design and user’s sex and may increase women’s injury risk. Clinical Relevance: Sex-specific ankle prophylactic designs may be warranted to reduce knee injury during sports.

scholarly journals Is There a Sex Difference in Trunk Neuromuscular Control among Recreational Athletes during Cutting Maneuvers?

2021 ◽  
pp. 743-750
Author(s):  
Guillaume Mornieux ◽  
Dominic Gehring ◽  
Albert Gollhofer
Keyword(s):  
Injury Risk ◽  
Neuromuscular Control ◽  
Trunk Muscles ◽  
Trunk Control ◽  
Joint Injury ◽  
Recreational Athletes ◽  
Peak Knee ◽  
Knee Abduction ◽  
Knee Joint Injury ◽  
Weight Acceptance

Trunk motion is most likely to influence knee joint injury risk, but little is known about sex-related differences in trunk neuromuscular control during changes of direction. The purpose of the present study was to test whether differences in trunk control between males and females during changes of direction exist. Twelve female and 12 male recreational athletes (with at least 10 years of experience in team sport) performed unanticipated changes of direction with 30° and 60° cut angles, while 3D trunk and leg kinematics, ground reaction forces and trunk muscles electromyography were recorded. Trunk kinematics at the time of peak knee abduction moment and directed co-contraction ratios for trunk muscles during the pre-activation and weight acceptance phases were determined. None of the trunk kinematics and co-contraction ratio variables, nor peak knee abduction moment differed between sexes. Compared to the 30° cut, trunk lateral flexion remained unchanged and trunk external rotation was reduced (p < 0.001; η²p (partial eta squared for effect size) = 0.78), while peak knee abduction moment was increased (p < 0.001; η²p = 0.84) at 60°. The sharper cutting angle induced muscle co-contraction during the pre-activation directed less towards trunk flexors (p < 0.01; η²p = 0.27) but more towards trunk medial flexors and rotators opposite to the movement direction (p < 0.001; η²p > 0.46). However, muscle co-contraction during the weight acceptance phase remained comparable between 30° and 60°. The lack of sex-related differences in trunk control does not explain knee joint injury risk discrepancies between sexes during changes of direction. Trunk neuromuscular strategies during sharper cutting angles revealed the importance of external oblique muscles to maintain trunk lateral flexion at the expense of trunk rotation. This provides new information for trunk strength training purposes for athletes performing changes of direction.

Ankle Dorsiflexion Affects Hip and Knee Biomechanics During Landing

2021 ◽  
pp. 194173812110196
Author(s):  
Jeffrey B. Taylor ◽  
Elena S. Wright ◽  
Justin P. Waxman ◽  
Randy J. Schmitz ◽  
James D. Groves ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Knee Flexion ◽  
Injury Risk ◽  
Female Athletes ◽  
Knee Extensor ◽  
Ankle Dorsiflexion ◽  
Level Of Evidence ◽  
Peak Knee ◽  
Knee Abduction ◽  
Lower Extremity Biomechanics

Background: Restricted ankle dorsiflexion range of motion (DFROM) has been linked to lower extremity biomechanics that place an athlete at higher risk for injury. Whether reduced DFROM during dynamic movements is due to restrictions in joint motion or underutilization of available ankle DFROM motion is unclear. Hypothesis: We hypothesized that both lesser total ankle DFROM and underutilization of available motion would lead to high-risk biomechanics (ie, greater knee abduction, reduced knee flexion). Study Design: Cross-sectional study. Level of Evidence: Level 3. Methods: Nineteen active female athletes (age, 20.0 ± 1.3 years; height, 1.61 ± 0.06 m; mass, 67.0 ± 10.7 kg) participated. Maximal ankle DFROM (clinical measure of ankle DFROM [DF-CLIN]) was measured in a weightbearing position with the knee flexed. Lower extremity biomechanics were measured during a drop vertical jump with 3-dimensional motion and force plate analysis. The percent of available DFROM used during landing (DF-%USED) was calculated as the peak DFROM observed during landing divided by DF-CLIN. Univariate linear regressions were performed to identify whether DF-CLIN or DF-%USED predicted knee and hip biomechanics commonly associated with injury risk. Results: For every 1.0° less of DF-CLIN, there was a 1.0° decrease in hip flexion excursion ( r2 = 0.21, P = 0.05), 1.2° decrease in peak knee flexion angles ( r2 = 0.37, P = 0.01), 0.9° decrease in knee flexion excursion ( r2 = 0.40, P = 0.004), 0.002 N·m·N−1·cm−1 decrease in hip extensor work ( r2 = 0.28, P = 0.02), and 0.001 N·m·N−1·cm−1 decrease in knee extensor work ( r2 = 0.21, P = 0.05). For every 10% less of DF-%USED, there was a 3.2° increase in peak knee abduction angles ( r2 = 0.26, P = 0.03) and 0.01 N·m·N−1·cm−1 lesser knee extensor work ( r2 = 0.25, P = 0.03). Conclusion: Lower levels of both ankle DFROM and DF-%USED are associated with biomechanics that are considered to be associated with a higher risk of sustaining injury. Clinical Relevance: While total ankle DFROM can predict some aberrant movement patterns, underutilization of available ankle DFROM can also lead to higher risk movement strategies. In addition to joint specific mobility training, clinicians should incorporate biomechanical interventions and technique feedback to promote the utilization of available motion.

scholarly journals Assessing the effect of back exoskeletons on injury risk during material handling

2021 ◽  
Author(s):  
Karl E Zelik ◽  
Cameron A Nurse ◽  
Mark C Schall ◽  
Richard F Sesek ◽  
Matthew C Marino ◽  
...  
Keyword(s):  
Occupational Health ◽  
Fatigue Failure ◽  
Real World ◽  
Injury Risk ◽  
Material Handling ◽  
Health Program ◽  
Assessment Tool ◽  
Assessment Tools ◽  
Low Back ◽  
Low Back Disorders

Low back disorders (LBDs) are a leading injury in the workplace. Back exoskeletons (exos) are wearable assist devices that complement traditional ergonomic controls and reduce LBD risks by alleviating musculoskeletal overexertion. However, there are currently no ergonomic assessment tools to evaluate risk for workers wearing back exos. Exo-LiFFT, an extension of the Lifting Fatigue Failure Tool, is introduced as a means to unify the etiology of LBDs with the biomechanical function of exos. We present multiple examples demonstrating how Exo-LiFFT can assess or predict the effect of exos on LBD risk without costly, time-consuming electromyography studies. For instance, using simulated and real-world material handling data we show an exo providing a 30 Nm lumbar moment is projected to reduce cumulative back damage by about 70% and LBD risk by about 20%. Exo-LiFFT provides a practical, efficient ergonomic assessment tool to assist safety professionals exploring back exos as part of a comprehensive occupational health program.

Debriefing Surgeons on Non-Technical Skills in the Operating Room - Results from a Pilot Study

2007 ◽  
Vol 51 (11) ◽  
pp. 663-667
Author(s):  
S. Yule ◽  
R. Flin ◽  
N. Maran ◽  
D. Rowley ◽  
G. Youngson ◽  
...  
Keyword(s):  
Operating Room ◽  
Cognitive Skills ◽  
Technical Skills ◽  
Assessment Tools ◽  
Valuable Adjunct ◽  
Surgical Trainees ◽  
Operative Surgery ◽  
Enhance Patient Safety ◽  
Behaviour Rating ◽  
Current Assessment

Briefing and debriefing are common practices for safety in high risk industries but are not systematically done in surgery. Regular debriefing of performance after operative surgery can greatly assist surgical trainees' development and help optimize learning from the limited time they spend in the Operating Room (OR). We developed and tested the NOTSS (Non-Technical Skills for Surgeons) behaviour rating system with subject matter experts. It allows surgeons to observe trainees' behaviour in the OR and provide them with structured feedback for improvement. This paper describes process of debriefing and the results of a pilot usability trial. The majority of participants reported that the NOTSS system was useful for debriefing trainees, provided a common language to discuss non-technical skills, and was a valuable adjunct to current assessment tools. Some surgeons found interpersonal skills more difficult to rate than cognitive skills. 73% felt that routine use of the system would enhance patient safety.

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