Are Previous Joint Injuries Associated with Muscle Performance in Volleyball Athletes?

Objective The aim of the present study is to determine whether previous shoulder and knee injuries were associated with isokinetic fatigue index and agonist/antagonist ratio of shoulder internal/external rotators and knee flexors/extensors in male volleyball athletes. Methods The current study is a cross-sectional investigation of 49 male elite volleyball players competing at a high level in Brazil. Isokinetic fatigue index and agonist/antagonist profiles were assessed during the preseason. Additionally, in order to record previous injuries, the athletes answered a standardized questionnaire. We conducted a receiver operating characteristic (ROC) curve analysis to determine the association strength and the clinically relevant cut-off point for variables presenting statistical significance for the area under the curve (AUC) (α = 0.05). An independent t-test was used to compare isokinetic variables between athletes with and without previous injury (α = 0.05). Results The results of the ROC curve analysis indicated that hamstring fatigue index values at 300 o /s were associated with the presence of previous knee injury (area under the curve [AUC] = 73%, p = 0.004), and shoulder external rotators fatigue index values at 360°/s were not associated with the presence of previous shoulder injury (AUC = 68%, p = 0.053). Conclusions Elite volleyball athletes who reported previous knee injuries were prone to a higher fatigue index than those reporting no injuries. Knee flexor resistance training might be useful for those athletes who reported knee injuries in the previous season.

Are Previous Joint Injuries Associated with Muscle Performance in Volleyball Athletes? / Lesões articulares prévias são associadas ao desempenho muscular de jogadores de voleibol?

Abstract Objective The aim of the present study is to determine whether previous shoulder and knee injuries were associated with isokinetic fatigue index and agonist/antagonist ratio of shoulder internal/external rotators and knee flexors/extensors in male volleyball athletes. Methods The current study is a cross-sectional investigation of 49 male elite volleyball players competing at a high level in Brazil. Isokinetic fatigue index and agonist/antagonist profiles were assessed during the preseason. Additionally, in order to record previous injuries, the athletes answered a standardized questionnaire. We conducted a receiver operating characteristic (ROC) curve analysis to determine the association strength and the clinically relevant cut-off point for variables presenting statistical significance for the area under the curve (AUC) (α = 0.05). An independent t-test was used to compare isokinetic variables between athletes with and without previous injury (α = 0.05). Results The results of the ROC curve analysis indicated that hamstring fatigue index values at 300o/s were associated with the presence of previous knee injury (area under the curve [AUC] = 73%, p= 0.004), and shoulder external rotators fatigue index values at 360°/s were not associated with the presence of previous shoulder injury (AUC = 68%, p= 0.053). Conclusions Elite volleyball athletes who reported previous knee injuries were prone to a higher fatigue index than those reporting no injuries. Knee flexor resistance training might be useful for those athletes who reported knee injuries in the previous season.

Resumo Objetivo O objetivo deste estudo é determinar se lesões prévias de ombro e joelho estavam associadas ao índice de fadiga isocinética e razão agonista/antagonista dos rotadores internos/externos do ombro e flexores/extensores do joelho em jogadores de voleibol. Métodos Esta é uma investigação transversal com 49 jogadores de voleibol de elite que competem em alto nível no Brasil. O índice de fadiga isocinética e os perfis de agonistas/antagonistas foram avaliados durante a pré-temporada. Além disso, para registro de lesões anteriores, os atletas responderam a um questionário padronizado. Conduzimos uma análise da curva de característica de operação do receptor (receiver operating characteristic, ROC) para determinar a força de associação e o ponto de corte clinicamente relevante de variáveis com significância estatística na área sob a curva (AUC) (α = 0,05). Um teste t independente comparou as variáveis isocinéticas entre atletas com e sem lesão prévia (α = 0,05). Resultados Os resultados da análise da curva ROC indicam que os valores do índice de fadiga dos isquiotibiais a 300o/s foram associados à presença de lesão prévia no joelho (área soba a curva [AUC] = 73%, p= 0,004), enquanto os valores do índice de fadiga dos rotadores externos do ombro a 360°/s não foram associados à presença de lesão prévia no ombro (AUC = 68%, p= 0.053). Conclusões Atletas de voleibol de elite que relataram lesões anteriores no joelho estavam propensos a um índice de fadiga maior do que aqueles que não relataram lesões. O treinamento de resistência de flexores do joelho pode ser útil para atletas com relatos de lesões no joelho na temporada anterior.

Association of Cycling Kinematics With Anterior Knee Pain in Mountain Bike Cyclists.

CONTEXT: Comfort and pain in cyclists are often discussed as a result of the posture on the bike, and bike fit, including motion analysis, is advocated as a strategy to minimize these conditions. The relationship between cycling kinematics, comfort, and pain is still debatable. OBJECTIVES: To investigate the association of ankle, knee, and trunk kinematics with the occurrence of anterior knee pain (AKP) in mountain bike cyclists. DESIGN: Cross-sectional study. METHODS: Fifty cross-country mountain bike cyclists (26 with AKP and 24 without AKP) had their pedaling kinematics assessed. Linear and angular data from trunk, hip, knee, ankle, and foot from cyclists with and without AKP were recorded using Retül motion analysis system. RESULTS: The binary logistic regression model showed that kinematic variables such as peak ankle plantar flexion, peak knee flexion, and forward trunk lean were significant predictors of AKP. Both larger peak plantar flexion and knee flexion decreased the probability of reporting AKP. On the other hand, larger forward trunk lean increased the probability of reporting AKP. CONCLUSIONS: Ankle, knee, and trunk sagittal kinematics may predict AKP in cross-country mountain bike cyclists, whereas hip, knee, and ankle alignment in the frontal plane showed no association with occurrence of AKP. In other words, cyclists with larger ankle plantar flexion and knee flexion are less likely to have AKP, whereas those with increased trunk forward lean are more likely to have AKP.

Interaction of foot and hip factors identifies Achilles tendinopathy occurrence in recreational runners.

OBJECTIVES: To investigate the interaction of ankle-foot complex and hip joint factors with Achilles Tendinopathy (AT) occurrence in recreational runners. DESIGN: Cross-sectional. SETTING: Research Laboratory. PARTICIPANTS: 51 runners, 26 healthy and 25 with AT. MAIN OUTCOMES MEASURES: Shank-forefoot alignment (SFA), weight bearing lunge test (WBLT), passive hip internal rotation (IR) range of motion (ROM), hip external rotators (ER) and ankle plantar flexors (PF) isometric strength. CART analyses were performed to assess interactions that could distinguish those with AT. RESULTS: Passive hip IR ROM, ankle PF torque, SFA, and hip ER isometric torque were associated AT occurrence. The model correctly classified 92% of individuals without AT and 72% of those with AT. The area under the receiver operating characteristic curve was 0.88. Interaction factors revealed in nodes 3 and 10 were statistically significant. In node 3, runners with more than 29.33° of passive hip IR ROM had a 130% increased likelihood (PR = 2.30) of AT. Node 10 showed that individuals with higher PF torque, SFA varus, ER torque, but reduced passive hip IR ROM had an 87% increased likelihood (PR = 1.87) of AT. CONCLUSION: Interactions between hip and foot factors could accurately classify recreational runners with and without AT.

Sports Injury Forecasting and Complexity: A Synergetic Approach.

The understanding that sports injury is the result of the interaction among many factors and that specific profiles could increase the risk of the occurrence of a given injury was a significant step in establishing programs for injury prevention. However, injury forecasting is far from being attained. To be able to estimate future states of a complex system (forecasting), it is necessary to understand its nature and comply with the methods usually used to analyze such a system. In this sense, sports injury forecasting must implement the concepts and tools used to study the behavior of self-organizing systems, since it is by self-organizing that systems (i.e., athletes) evolve and adapt (or not) to a constantly changing environment. Instead of concentrating on the identification of factors related to the injury occurrence (i.e., risk factors), a complex systems approach looks for the high-order variables (order parameters) that describe the macroscopic dynamic behavior of the athlete. The time evolution of this order parameter informs on the state of the athlete and may warn about upcoming events, such as injury. In this article, we describe the fundamental concepts related to complexity based on physical principles of self-organization and the consequence of accepting sports injury as a complex phenomenon. In the end, we will present the four steps necessary to formulate a synergetics approach based on self-organization and phase transition to sports injuries. Future studies based on this experimental paradigm may help sports professionals to forecast sports injuries occurrence.

Physical Therapy Service delivered in the Polyclinic During the Rio 2016 Paralympic Games.

OBJECTIVE: To characterize the Physical Therapy Services delivered at the Polyclinic during the Rio 2016 Paralympic Games. DESIGN: Retrospective Cohort Study. SETTING: Physical Therapy Services (PTS) of the Polyclinic. PARTICIPANTS: Athletes attended for Physical Therapy treatment at the Polyclinic during Rio 2016 Paralympic Games. MAIN OUTCOME MEASURES: The number of athletes treated, their nationalities, their sports modality, the most frequently treated regions and the interventions applied. RESULTS: A total of 4504 interventions were delivered and 399 athletes were treated in the PTS. Athletes representing athletics and sitting volleyball were the most frequently attended for treatment. The main diagnoses were muscle tension and tendinopathy. Analgesia was the main purpose of treatment and myofascial release and electrotherapy was the most frequent interventions. Recovery service had a total of 1579 encounters and male athletes used cryo-immersion 3 times more when compared to female. CONCLUSION: Athletes representing athletics and sitting volleyball were the most frequently attended for treatment and the thoracic/lumbar spine and pelvis/hip were the most commonly affected regions. Muscle strain and tendinopathy were the most frequent diagnoses and myofascial release and electrotherapy were the most frequent therapies used to achieve analgesia.

Factors associated with the presence of patellar tendon abnormalities in male athletes.

OBJECTIVES: To investigate the association between lower limb alignment, range of motion/flexibility and muscle strength with the presence of patellar tendon abnormalities in male athletes. DESIGN: This was a cross-sectional study. METHODS: Thirty-one male basketball and volleyball athletes were assessed for ankle dorsiflexion range of motion, shank-forefoot alignment, iliotibial band flexibility, hip external rotators and abductors isometric torque, passive hip internal rotation range of motion and frontal plane knee and patellar alignment (McConnell and Arno angles). Ultrasonographic evaluations of hypoechoic areas of the patellar tendons were performed in longitudinal and transverse planes. A receiver operating characteristic curve was used to determine clinically relevant cut-off point for each variable. When the area under the curve was statistically significant, Prevalence Ratio (PR) and 95% confidence intervals were calculated to indicate the strength of the association between the independent variable and the presence of patellar tendon abnormalities. RESULTS: Receiver operating characteristic curve showed that iliotibial band flexibility (p=0.006), shank-forefoot alignment (p=0.013) and Arno angle (p=0.046) were associated with patellar tendon abnormalities. Cut-off points were established and only the Prevalence Ratio of iliotibial band flexibility (cut-off point=-0.02°/kg; PR=5.26) and shank-forefoot alignment (cut-off point=24°; PR=4.42) were statistically significant. CONCLUSIONS: Athletes with iliotibial band or shank-forefoot alignment above the clinically relevant cut-off point had more chance to have patellar tendon abnormalities compared to athletes under the cut-off point values. These results suggest that such factors could contribute to patellar tendon overload, since patellar tendon abnormalities indicate some level of tissue damage. Both factors might be considered in future prospective studies.

Foot and hip contributions to high frontal plane knee projection angle in athletes: a classification and regression tree approach.

STUDY DESIGN: Cross-sectional. OBJECTIVE: To investigate predictors of increased frontal plane knee projection angle (FPKPA) in athletes. BACKGROUND: The underlying mechanisms that lead to increased FPKPA are likely multifactorial and depend on how the musculoskeletal system adapts to the possible interactions between its distal and proximal segments. Bivariate and linear analyses traditionally employed to analyze the occurrence of increased FPKPA are not sufficiently robust to capture complex relationships among predictors. The investigation of nonlinear interactions among biomechanical factors is necessary to further our understanding of the interdependence of lower-limb segments and resultant dynamic knee alignment. METHODS: The FPKPA was assessed in 101 athletes during a single-leg squat and in 72 athletes at the moment of landing from a jump. The investigated predictors were sex, hip abductor isometric torque, passive range of motion (ROM) of hip internal rotation (IR), and shank-forefoot alignment. Classification and regression trees were used to investigate nonlinear interactions among predictors and their influence on the occurrence of increased FPKPA. RESULTS: During single-leg squatting, the occurrence of high FPKPA was predicted by the interaction between hip abductor isometric torque and passive hip IR ROM. At the moment of landing, the shank-forefoot alignment, abductor isometric torque, and passive hip IR ROM were predictors of high FPKPA. In addition, the classification and regression trees established cutoff points that could be used in clinical practice to identify athletes who are at potential risk for excessive FPKPA. CONCLUSION: The models captured nonlinear interactions between hip abductor isometric torque, passive hip IR ROM, and shank-forefoot alignment.