Modifying landing mat material properties may decrease peak contact forces but increase forefoot forces in gymnastics landings

The effect of safety modifications on head kinematics experienced during common skills in women's artistic gymnastics

The objective of this study was to evaluate the effect of skill modifications on head motion experienced during women's artistic gymnastics skills. Nine gymnasts (four beginner and five advanced) completed three trials of up to 24 skill progressions, each consisting of a skill and two progressive safety modifications. Gymnasts were instrumented with mouthpiece sensors embedded with an accelerometer and gyroscope collecting motion data at 200, 300, and 500 Hz during each skill performance. Peak-to-peak linear and rotational kinematics during contact phases and peak rotational kinematics during non-contact phases were computed. A mixed-effects model was used to compare differences in modification status nested within skill categories. Timer skills (i.e. drills that simulate performance of a gymnastics skill) resulted in the highest median ΔLA and ΔRA of all skill categories, and 132 skill performances exceeded 10 g ΔLA during a contact phase. Modifications were associated with significant reductions in head kinematics during contact phases of timers, floor skills, bar releases, and vault skills. Gymnasts can be exposed to direct and indirect head accelerations at magnitudes consistent with other youth contact sports, and common safety modifications may be effective at reducing head motion during contact and non-contact phases of gymnastics skills.

A Research and Clinical Framework for Understanding Achilles Injury in Female Collegiate Gymnasts

ABSTRACT

Gymnastics is a popular sport with a high injury rate, particularly at the collegiate level. Achilles tendon rupture is a catastrophic injury with career-changing impact. Over the last decade, there has been a growing incidence of Achilles tendon ruptures, especially in female gymnasts. Currently, neither the effects of contributing risk factors on Achilles tendon rupture nor the research frameworks to guide future intervention strategies have been well described. This article reviews the functional anatomy and mechanical properties of the Achilles tendon, provides precollegiate and collegiate intrinsic and extrinsic risk factors for Achilles tendon rupture, and proposes a research framework to address this injury from a systemic perspective. Potential clinical interventions to mitigate Achilles tendon injury are proposed based on currently available peer-reviewed evidence.

Current issues and future directions in gymnastics research: biomechanics, motor control and coaching interface

The sport of gymnastics is undergoing a global examination of its culture and the relationship between the gymnast, coach and environment is a central focus. The aim of this review is to explore biomechanics and motor control research in skill development and technique selection in artistic gymnastics with a focus on the underlying concepts and scientific principles that allow performance enhancement, skill development and injury risk reduction. The current review examines peer reviewed papers from 2000 onwards, with a focus on contemporary approaches in the field of gymnastics research, and highlights several key directions for future gymnastics research. Based on our review and the integration of the models of Newell (1986) and Irwin et al. (2005), we recommend that future gymnastics research should embrace at the very least a multidisciplinary approach and aim for an interdisciplinary paradigm.

Wrist pain in gymnasts: Efficacy of a wrist brace to decrease wrist pain while performing gymnastics

STUDY DESIGN

This was a clinical trial of prospective cohort.

INTRODUCTION

Wrist pain in gymnasts is a global phenomenon. Compression forces acting on wrists while performing gymnastics is a predisposing factor in the development of wrist pain and consequential injury of the distal radial physis in skeletally immature gymnasts. One approach to mitigate these forces is wrist bracing; however, studies on the efficacy of wrist braces to reduce wrist pain experienced by gymnasts are limited.

PURPOSE OF THE STUDY

The purpose of this study was to investigate the efficacy of an innovative design of a wrist brace to decrease gymnasts' wrist pain while performing gymnastics.

METHODS

A wrist brace was designed and trialled over 3 weeks by 48 male gymnasts (aged 8-22 years, levels 4-7) with wrist pain. Wrist pain was recorded on a visual analog scale of 1 to 10 before and after trial. Data analysis was performed using SPSS-22 (IBM Inc). Paired t-tests were performed to compare variables before and after trial, with effect size analyses used to quantify the relative magnitude of any differences.

RESULTS

Paired t-tests indicated the gymnasts reported significantly reduced pain (P = .002; 53.5%) while wearing the braces for training on the pommel, floor, and parallel bars. The overall large effect size value was practically significant (d = 0.902).

DISCUSSION

For any wrist brace to be effective, it needs to be implemented when the gymnast experiences wrist pain before an injury occurs. This would minimize the development of pain-provoked adaptive movement patterns that perpetuate dysfunction.

CONCLUSIONS

The brace with the volar gel pad is recommended to be worn as an adjunct to current strategies in management of gymnasts' wrist pain or as an injury prevention device in skeletally immature gymnasts.

A Review of Forward-Dynamics Simulation Models for Predicting Optimal Technique in Maximal Effort Sporting Movements

The identification of optimum technique for maximal effort sporting tasks is one of the greatest challenges within sports biomechanics. A theoretical approach using forward-dynamics simulation allows individual parameters to be systematically perturbed independently of potentially confounding variables. Each study typically follows a four-stage process of model construction, parameter determination, model evaluation, and model optimization. This review critically evaluates forward-dynamics simulation models of maximal effort sporting movements using a dynamical systems theory framework. Organismic, environmental, and task constraints applied within such models are critically evaluated, and recommendations are made regarding future directions and best practices. The incorporation of self-organizational processes representing movement variability and “intrinsic dynamics” remains limited. In the future, forward-dynamics simulation models predicting individual-specific optimal techniques of sporting movements may be used as indicative rather than prescriptive tools within a coaching framework to aid applied practice and understanding, although researchers and practitioners should continue to consider concerns resulting from dynamical systems theory regarding the complexity of models and particularly regarding self-organization processes.

Surgical Repair of Complete Plantar Fascia Ruptures in High-Demand Power Athletes: An Alternative Treatment Option

Surgical repair of complete plantar fascia ruptures has not yet been reported in the literature. Operative technique and outcome are described in 2 gymnasts with heavy plyometric demands who received surgical repair compared with 3 athletes treated nonoperatively. Biomechanics and clinical implications are discussed. In the last 8 years, we have seen 5 high-demand athletes with total rupture of the plantar fascia. This is a retrospective clinical evaluation 1.5 to 8 years postinjury of all 5 patients using dynamic ultrasound, Foot Function Index, sports-specific questions, Foot Posture Index, and foot length. The operated gymnasts returned to the same level of performance within 12 months. None of the conservatively treated athletes returned to preinjury plyometric sports levels but reached a foot load capacity of distance running with the injured foot as limiting factor. Ultrasound with simultaneous dorsiflexion of the toes showed a normal fascia in the operated patients, but a slack fascia that tightened up only at terminal toe dorsiflexion in the conservatively treated group. According to the Foot Function Index, the operated patients reported no complaints, whereas the nonoperative group had clinical relevant impairments in activities of daily life. The Foot Posture Index in all nonoperated patients showed a relative shift toward pronation with increased foot length compared with the noninjured foot. The operated patients showed no difference in foot length but minimal shift into supination with a slightly altered arch contour. Surgical repair of plantar fascia ruptures is technically feasible to restore normal foot load capability with return to high-demand plyometric sports within 12 months.

The Relationship of Shoulder and Elbow Stresses and Upper Limb Contact Order During a Round-Off Back Handspring

INTRODUCTION

Despite high injury incidence rates in gymnastics, there is a paucity of data characterizing upper extremity injury causation and biomechanical risk factors. This study investigated contact forces across multiple joints in both upper extremities during a round-off back handspring (ROBHS), a fundamental gymnastics tumbling maneuver.

OBJECTIVE

(1) To characterize the three-dimensional (3-D) biomechanics of the sequential, asynchronous contact of each upper extremity with the ground during a ROBHS using 3-D motion capture, and (2) to evaluate potential correlations to upper extremity injury risk.

DESIGN

Observational cross-sectional study.

SETTING

Controlled laboratory environment.

PARTICIPANTS

Fourteen competitive female gymnasts aged 10-21 years (mean age: 16.6 ± 3.1 years) (1) participating on a competitive gymnastics team; (2) capable of successfully completing a ROBHS; and (3) free of reported injury at enrollment.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Variables evaluated include joint angle, torque, compression force, ground reaction force (GRF), time to peak GRF, and limb loading rates. Variables were analyzed at the wrist, elbow, and shoulder of both limbs at ground contact. The hypothesis that these dependent variables would differ by ROBHS upper extremity contact order was formulated retrospectively after data collection.

RESULTS

The first contact limb experienced significantly greater extension torque at the elbow (first: 48.89 ± 18.01 Nm, second: 22.49 ± 9.19 Nm; P = .014; CI 95% [14.83, 37.97]) and faster time to peak GRF (P < .001, CI 95% [-1.79, -0.99]). The second limb of contact experienced significantly greater abduction torque at the shoulder (P = .007; CI 95% [-21.58,-8.08]) and anterior-posterior GRF at contact (P = .007; CI 95% [-1.06,-0.26]).

CONCLUSIONS

The biomechanical differences between contact limbs during the ROBHS may lead to different injury risk. Recognition of the stresses at the elbow and shoulder for both limbs also provides new insight for rehabilitation clinicians to consider when guiding patients to return to gymnastics activity after injury.

Sport Specialization and Fitness and Functional Task Performance Among Youth Competitive Gymnasts

CONTEXT

Gymnastics trains fundamental movement skills but has high rates of early sport specialization. Early specialization is associated with increased injury risk. Gymnasts devote time to developing technical skill, but whether specialization status influences performance is unknown.

OBJECTIVE

To describe the participation and specialization characteristics of youth club gymnastics participants and determine whether the level of specialization is associated with fitness and functional task performance.

DESIGN

Retrospective cross-sectional study.

SETTING

A single gymnastics facility.

PATIENTS OR OTHER PARTICIPANTS

Data on youth gymnasts (n = 131; 84 females, 47 males; age = 10.9 ± 2.9 years, height = 142.14 ± 16.23 cm, mass = 38.15 ± 12.93 kg) were reviewed.

MAIN OUTCOME MEASURE(S)

Specialization was assessed using a 3-tiered classification. Fitness measurements consisted of the Gymnastics Functional Measurement Tool, Men's Gymnastics Functional Measurement Tool, and core strength. Functional tasks evaluated hop performance, dynamic balance, and jump-landing technique. Separate analyses of covariance, covaried by age, hours of training, and years of gymnastics participation, were used to identify differences in fitness and functional performance among specialization groups. Pearson product correlations were calculated to evaluate the relationships between training hours per week and years in gymnastics with fitness and functional performance.

RESULTS

Most gymnasts were classified as moderately (50.4%, n = 66) or highly (35.1%, n = 46) specialized. Only 14.5% (n = 19) were classified as having a low level of specialization. Weak to moderate correlations were present between years in gymnastics and most fitness tasks. Moderate to strong correlations were noted between training hours per week and most fitness tasks. Low-specialization gymnasts scored lower on right lower extremity Y-balance (P = .004), upper left extremity Y-balance (P = .033), and right hop performance (P = .039) tests.

CONCLUSIONS

Gymnasts reported high proportions of moderate to high specialization, and many exceeded guidelines for hours participating in gymnastics per week. We did not observe clinically meaningful group differences among specialization status and fitness or functional movement tasks, indicating no clear benefit of gymnastics training to the exclusion of other sports for increased performance.

Mechanical Impedance and Its Relations to Motor Control, Limb Dynamics, and Motion Biomechanics

The concept of mechanical impedance represents the interactive relationship between deformation kinematics and the resulting dynamics in human joints or limbs. A major component of impedance, stiffness, is defined as the ratio between the force change to the displacement change and is strongly related to muscle activation. The set of impedance components, including effective mass, inertia, damping, and stiffness, is important in determining the performance of the many tasks assigned to the limbs and in counteracting undesired effects of applied loads and disturbances. Specifically for the upper limb, impedance enables controlling manual tasks and reaching motions. In the lower limb, impedance is responsible for the transmission and attenuation of impact forces in tasks of repulsive loadings. This review presents an updated account of the works on mechanical impedance and its relations with motor control, limb dynamics, and motion biomechanics. Basic questions related to the linearity and nonlinearity of impedance and to the factors that affect mechanical impedance are treated with relevance to upper and lower limb functions, joint performance, trunk stability, and seating under dynamic conditions. Methods for the derivation of mechanical impedance, both those for within the system and material-structural approaches, are reviewed. For system approaches, special attention is given to methods aimed at revealing the correct and sufficient degree of nonlinearity of impedance. This is particularly relevant in the design of spring-based artificial legs and robotic arms. Finally, due to the intricate relation between impedance and muscle activity, methods for the explicit expression of impedance of contractile tissue are reviewed.

Biomechanical approaches to identify and quantify injury mechanisms and risk factors in women's artistic gymnastics

Targeted injury prevention strategies, based on biomechanical analyses, have the potential to help reduce the incidence and severity of gymnastics injuries. This review outlines the potential benefits of biomechanics research to contribute to injury prevention strategies for women's artistic gymnastics by identification of mechanisms of injury and quantification of the effects of injury risk factors. One hundred and twenty-three articles were retained for review after searching electronic databases using key words, including 'gymnastic', 'biomech*', and 'inj*', and delimiting by language and relevance to the paper aim. Impact load can be measured biomechanically by the use of instrumented equipment (e.g. beatboard), instrumentation on the gymnast (accelerometers), or by landings on force plates. We need further information on injury mechanisms and risk factors in gymnastics and practical methods of monitoring training loads. We have not yet shown, beyond a theoretical approach, how biomechanical analysis of gymnastics can help reduce injury risk through injury prevention interventions. Given the high magnitude of impact load, both acute and accumulative, coaches should monitor impact loads per training session, taking into consideration training quality and quantity such as the control of rotation and the height from which the landings are executed.