How reliable are lower limb biomechanical evaluations during volleyball-specific jump-landing tasks?

BACKGROUND: Biomechanical evaluations of sport-specific jump-landing tasks may provide a more ecologically valid interpretation compared to generic jump-landing tasks. For accurate interpretation of longitudinal research, it is essential to understand the reliability of biomechanical parameters of sport-specific jump-landing tasks. RESEARCH QUESTION: How reliable are hip, knee and ankle joint angles and moment curves during two volleyball-specific jump-landing tasks and is this comparable with the reliability of a generic jump-landing task? METHODS: Three-dimensional (3D) biomechanical analyses of 27 male volleyball players were performed in two sessions separated by one week. Test-retest reliability was analyzed by calculating integrated as well as 1D intraclass correlation coefficient (ICC) and integrated standard error of measurement (SEM) for hip, knee and ankle angles and moments during a spike and block jump (volleyball-specific tasks), and during a drop vertical jump (generic task). RESULTS: Reliability of joint angles of volleyball-specific and generic jump-landing tasks are similar with excellent-to-good integrated ICC for hip, knee and ankle flexion/extension (ICC= 0.61-0.89) and hip and knee abduction/adduction (ICC=0.61-0.78) but fair-to-poor ICC for ankle abduction/adduction (ICC=0.28-0.52) and hip, knee and ankle internal/external rotation (ICC=0.29-0.53). Reliability of hip, knee and ankle joint moments was good-to excellent (ICC= 0.62-0.86) except for hip flexion moment during spike jump and drop vertical jump (ICC=0.43-0.47) and knee flexion moment during both volleyball-specific tasks (ICC=0.56-0.57). For all tasks, curve analysis revealed poorer reliability at start and end of the landing phase than during the midpart. SIGNIFICANCE: Our data suggests that kinematic evaluations of volleyball-specific jump-landing tasks are reliable to use in screening programs, especially in the sagittal plane. Notably, reliability is poorer at the beginning and end of the landing phase, requiring careful interpretation. In conclusion, the results of this study indicate the potential for integration of sport-specific jump-landing tasks in screening programs, which will be more ecologically valid.

The effect of fatigue on spike jump biomechanics in view of patellar tendon loading in volleyball.

BACKGROUND AND OBJECTIVE: Patellar tendinopathy (PT) is a highly prevalent overuse injury in volleyball and is often linked with overloading of the patellar tendon. Little is known, however, about whether and how patellar tendon loading is affected by fatigue during the most challenging jump activity in volleyball. Therefore, this study investigates the effect of a high-intensity, intermittent fatigue protocol on movement alterations in terms of patellar tendon loading during a volleyball spike jump. METHODS: Forty-three male volleyball players participated in this study. Three-dimensional full-body kinematics and kinetics were collected when performing a spike jump before and after the fatigue protocol. Sagittal plane joint angles, joint work and patellar tendon loading were calculated and analyzed with curve analyses using paired sample t-tests to investigate fatigue effects (p < 0.05). RESULTS: Fatigue induced a stiffer lower extremity landing strategy together with prolonged pelvis-trunk flexion compared to baseline (p = 0.001-0.005). Decreased patellar tendon forces (p = 0.001-0.010) and less eccentric knee joint work (-5%, p < 0.001) were observed after the fatigue protocol compared to baseline. CONCLUSION: Protective strategies seem to be utilized in a fatigued state to avoid additional tensile forces acting on the patellar tendon, including proximal compensations and stiff lower extremity landings. We hypothesize that players might be more prone for developing PT if eccentric patellar tendon loads are high in the non-fatigued state and/or these loads are somehow not decreased after fatigue.

The development of a clinical screening tool to evaluate unilateral landing performance in a healthy population.

OBJECTIVES: To develop a clinical tool to evaluate unilateral landing quality in a healthy population. The reliability of the novel tool was evaluated, and the influence of gender and leg-dominance was investigated. DESIGN: An experimental study for developing a test protocol, scoring criteria, and scoring method, based on observable landing errors, for the novel Unilateral Landing Error Scoring System (ULESS). SETTING: Controlled lab environment. PARTICIPANTS: Healthy participants (25♂ and 25♀) performed the ULESS. MAIN OUTCOME MEASURES: The ULESS was scored with video analysis. Unilateral landing performance, measured with the ULESS, was compared to bilateral landing performance. RESULTS: Sixteen items to assess trunk, pelvic, and lower limb movement patterns during a unilateral landing task resulted in a composite score on an interval scale. Moderate to excellent intra- and inter-tester reliability (ICC(2,1) = 0.77-0.90) was determined. The ULESS was able to identify moderate to poor unilateral landing quality in subjects with good to excellent bilateral landing quality. No main effect of gender (p = 0.19) or leg-dominance (p = 0.65) on ULESS scores was found. CONCLUSION: Moderate to excellent reliability can be expected when using the newly developed protocol and scoring method. The ULESS is feasible to perform with limited materials.

The role of core stability in the development of non-contact acute lower extremity injuries in an athletic population: A prospective study.

OBJECTIVES: Stability of the core is associated with lower extremity functioning. Consequently, impaired core stability might play a role in developing non-contact acute lower extremity sports injuries. The objective was to investigate components of core stability as potential risk factors for acute lower extremity injuries. DESIGN: A cohort study was set up with a follow-up and injury registration period of 1.5 years. PARTICIPANTS: 142 male and female physical education students were included. MAIN OUTCOME MEASURES: Measures of isometric hip and core muscular strength, endurance, proprioception and neuromuscular control of the core, and postural control were taken at the start of the study. Sports-related injury occurrence was registered during follow-up. RESULTS: 27 (19%) injuries of interest occurred during follow-up. After multivariate model building, a significant predictive effect was found for side-to-side hip abduction strength asymmetry (p = .007). The hazard of developing an acute lower extremity injury increased with 6.2% with a 1 unit increase in side-to-side strength imbalance, regardless of gender. CONCLUSION: Hip abduction strength imbalance was determined as a risk factor for the development of non-contact, acute lower extremity injuries. Normalizing hip strength imbalances might be beneficial for injury prevention. However, further research is needed to support this claim.

Relationship Between Jump-Landing Kinematics and Lower Extremity Overuse Injuries in Physically Active Populations: A Systematic Review and Meta-Analysis.

BACKGROUND: Lower extremity overuse injuries are common in athletes participating in sports with repeated bouts of landing manoeuvres. Biomechanical alterations during landing may be associated with these types of injuries. The objective of this systematic review with meta-analysis was to summarise and determine the relationship between kinematic alterations during a landing task and the development of lower extremity overuse injuries in physically active populations. METHODS: PubMed, Embase, Web of Science, CINAHL, and SPORTDiscus were consulted up to and including February 2020. Cohort, cross-sectional or case-control studies were included if they investigated the relationship between three-dimensional (3D) landing kinematics in physically active populations and either new incidence or a history of lower extremity overuse injuries. RESULTS: Twenty-three studies that investigated 3D landing kinematics in subjects with either patellar tendinopathy (PT), patellofemoral pain (PFP), exertional medial tibial pain (EMTP) or groin overuse injury met the inclusion criteria. Based on this systematic review, there is evidence for decreased knee flexion range of motion (ROM) and increased knee abduction ROM during landing as risk factors for PFP. For PT, risk factors are poorly understood. Furthermore, the meta-analysis demonstrated significantly greater hip adduction at initial contact (IC) (p = 0.02), greater knee internal rotation at IC (p < 0.001), greater peak knee external rotation (p = 0.05) and less ankle dorsiflexion at peak vertical ground reaction force (vGRF) (p = 0.05) in subjects with knee overuse injuries compared to healthy controls. There is evidence of increased trunk, hip and knee transversal ROM as risk factors for EMTP. Groin injuries are associated with greater pelvic and hip frontal and transversal plane ROM in the injured group compared to the healthy controls. CONCLUSION: The results of this systematic review and meta-analysis provide preliminary evidence for impaired landing kinematics associated with lower extremity overuse injuries. Excessive frontal and transversal plane movements during landing manoeuvres might increase impact and tensile forces resulting in lower extremity overuse injuries. REGISTRATION: This systematic review was registered in the PROSPERO international prospective register of systematic reviews (ID = CRD42019135602).