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.

Efficacy of Hip Strengthening on Pain Intensity, Disability, and Strength in Musculoskeletal Conditions of the Trunk and Lower Limbs: A Systematic Review with Meta-Analysis and Grade Recommendations.

To investigate the efficacy of hip strengthening on pain, disability, and hip abductor strength in musculoskeletal conditions of the trunk and lower limbs, we searched eight databases for randomized controlled trials up to 8 March 2022 with no date or language restrictions. Random-effect models estimated mean differences (MDs) with 95% confidence intervals (CIs), and the quality of evidence was assessed using the GRADE approach. Very low quality evidence suggested short-term effects (≤3 months) of hip strengthening on pain intensity (MD of 4.1, 95% CI: 2.1 to 6.2; two trials, n = 48 participants) and on hip strength (MD = 3.9 N, 95% CI: 2.8 to 5.1; two trials, n = 48 participants) in patellofemoral pain when compared with no intervention. Uncertain evidence suggested that hip strengthening enhances the short-term effect of the other active interventions on pain intensity and disability in low back pain (MD = -0.6 points, 95% CI: 0.1 to 1.2; five trials, n = 349 participants; MD = 6.2 points, 95% CI: 2.6 to 9.8; six trials, n = 389 participants, respectively). Scarce evidence does not provide reliable evidence of the efficacy of hip strengthening in musculoskeletal conditions of the trunk and lower limbs.