Natália F. N. Bittencourt

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.

Análise do perfil, funções e habilidades do fisioterapeuta com atuação na área esportiva nas modalidades de futebol e voleibol no Brasil

OBJECTIVE: To analyze the profile of Brazilian physical therapists working with soccer and volleyball professional teams, by verifying their level of education (graduate or undergraduate), as well as their role and insertion within the interdisciplinary team. METHODS: Structured questionnaires were administered to forty-nine physical therapists working at soccer, volleyball clubs and Brazilian national teams. These questionnaires provided data on social demographic, characteristics of the work environment and organization of clinical practice and its domains. RESULTS: From the 49 participants in this study only five were female. Mean age of all participants was 32.2 years. The majority of the sports physical therapists had specialization degrees in different areas (78.2%), were hired through referral (78.2%), worked more than 8 hours a day or were exclusively dedicated to their clubs (80.0%) and earned seven to ten Brazilian minimal wages (58.2%). They reported to have participation in the domains of emergency care (87.3%), prevention (92.7%), functional rehabilitation (98.2%) and return to competition (100%). They had interdisciplinary relationships with physical educators during functional rehabilitation programs (70.9%) and with physicians in the decision process of return to activity after rehabilitation (74.5%) and on the veto of an athlete to take part in practices or matches (63.6%). Therapists also complained of threats to their professional autonomy, specially directed by the teams physician. CONCLUSION: There is still a need to invest in continuing education of sports physical therapists with the objective to improve their educational level and to strengthen their professional autonomy.

Avaliação muscular isocinética da articulação do joelho em atletas das seleções brasileiras infanto e juvenil de voleibol masculino

The vertical jump is a basic volleyball practice that demands a high ability to generate strength and work in the muscles involved, mainly in the quadriceps muscle. Due to such demand, muscle imbalances between extensor and flexor muscles may be present, causing an overloading on the muscle-tendinous structures of the knee joint. Thus, the establishment of normal parameters for the muscle function related to that joint in volleyball athletes is necessary. Therefore, the purpose of this study was to assess through isokinetic dynamometry the peak torque, work peak, agonist/antagonist ratio, and fatigue index of the flexor and extensor of the knee among both volleyball athlete population. The isokinetic flexion and extension tests of the knees were performed in the concentric-concentric seat mode at 60 and 300o/sec. velocity in thirty-six athletes (20 under 19-under 21, and 16 under 21). The data allowed to set the parameters for the muscle function of the knee joint among athletes of the 2003 Under 19-Under 21 and Under 21 Brazilian National Team Selection of Male Volleyball. Athletes presented peak torque and work peak values normalized by the body mass to the upper quadriceps to the mean normal values for the athletes and non-athletes populations. Compared to other categories, the under 21 athletes presented significantly higher values for the agonist/antagonist ratio, and peak work ratio of the knee flexors at 60o/sec. velocity. Furthermore, the agonist/antagonist ratio was lower than the reference value expected for both categories, thus characterizing predominance in the extensor musculature over the flexor musculature. The fatigue index was close to what would be expected for the majority of athletes. The present study may be useful as comparison basis for future studies aiming evaluate the isokinetic muscle function in volleyball players.The vertical jump is a basic volleyball practice that demands a high ability to generate strength and work in the muscles involved, mainly in the quadriceps muscle. Due to such demand, muscle imbalances between extensor and flexor muscles may be present, causing an overloading on the muscle-tendinous structures of the knee joint. Thus, the establishment of normal parameters for the muscle function related to that joint in volleyball athletes is necessary. Therefore, the purpose of this study was to assess through isokinetic dynamometry the peak torque, work peak, agonist/antagonist ratio, and fatigue index of the flexor and extensor of the knee among both volleyball athlete population. The isokinetic flexion and extension tests of the knees were performed in the concentric-concentric seat mode at 60 and 300o/sec. velocity in thirty-six athletes (20 under 19-under 21, and 16 under 21). The data allowed to set the parameters for the muscle function of the knee joint among athletes of the 2003 Under 19-Under 21 and Under 21 Brazilian National Team Selection of Male Volleyball. Athletes presented peak torque and work peak values normalized by the body mass to the upper quadriceps to the mean normal values for the athletes and non-athletes populations. Compared to other categories, the under 21 athletes presented significantly higher values for the agonist/antagonist ratio, and peak work ratio of the knee flexors at 60o/sec. velocity. Furthermore, the agonist/antagonist ratio was lower than the reference value expected for both categories, thus characterizing predominance in the extensor musculature over the flexor musculature. The fatigue index was close to what would be expected for the majority of athletes. The present study may be useful as comparison basis for future studies aiming evaluate the isokinetic muscle function in volleyball players.

Avaliação muscular isocinética da articulação do ombro em atletas da Seleção Brasileira de voleibol sub-19 e sub-21 masculino

INTRODUCTION AND PURPOSE: The shoulder complex muscles play an important role in force, power and endurance production in volleyball, allowing the accomplishment of movement in a coordinated manner. The objective written account produced by isokinetic evaluations assists in the diagnosis and prevention of shoulder complex injuries. In addition, it is a useful tool in promoting safe and fast return of the injured athlete to sports practice. The purpose of this study was to analyze the isokinetic muscle performance of the lateral and medial rotators of the glenohumeral joint in Brazilian male volleyball teams (under-19 and under-21). METHODS: The protocol used during the test included five maximum repetitions of shoulder lateral and medial rotation in concentric-concentric mode at 60o/s and 30 repetitions at 360o/s. Analysis of variance was used to evaluate the dependent variables: maximum work and maximum torque of shoulder lateral and medial rotators normalized by body mass, antagonist/agonist ratio at the two speeds and muscular fatigue index. RESULTS: Data analysis demonstrated an imbalance between the shoulder lateral and medial rotators (antagonist/agonist ratio) in the under-21 category of the Brazilian volleyball athletes, demonstrating relative weakness of the lateral rotators. CONCLUSION: It was possible to identify changes in volleyball players, which added to specific demands of the sport, can lead to symptoms in the shoulder complex and / or decrease of performance.

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.

Isokinetic muscle evaluation of the knee joint in athletes of the Under-19 and Under-21 Male Brazilian National Volleyball Team

The vertical jump is a basic volleyball practice that demands a high ability to generate strength and work in the muscles involved, mainly in the quadriceps muscle. Due to such demand, muscle imbalances between extensor and flexor muscles may be present, causing an overloading on the muscle-tendinous structures of the knee joint. Thus, the establishment of normal parameters for the muscle function related to that joint in volleyball athletes is necessary. Therefore, the purpose of this study was to assess through isokinetic dynamometry the peak torque, work peak, agonist/antagonist ratio, and fatigue index of the flexor and extensor of the knee among both volleyball athlete population. The isokinetic flexion and extension tests of the knees were performed in the concentric-concentric seat mode at 60 and 300o/sec. velocity in thirty-six athletes (20 under 19-under 21, and 16 under 21). The data allowed to set the parameters for the muscle function of the knee joint among athletes of the 2003 Under 19-Under 21 and Under 21 Brazilian National Team Selection of Male Volleyball. Athletes presented peak torque and work peak values normalized by the body mass to the upper quadriceps to the mean normal values for the athletes and non-athletes populations. Compared to other categories, the under 21 athletes presented significantly higher values for the agonist/antagonist ratio, and peak work ratio of the knee flexors at 60o/sec. velocity. Furthermore, the agonist/antagonist ratio was lower than the reference value expected for both categories, thus characterizing predominance in the extensor musculature over the flexor musculature. The fatigue index was close to what would be expected for the majority of athletes. The present study may be useful as comparison basis for future studies aiming evaluate the isokinetic muscle function in volleyball players.The vertical jump is a basic volleyball practice that demands a high ability to generate strength and work in the muscles involved, mainly in the quadriceps muscle. Due to such demand, muscle imbalances between extensor and flexor muscles may be present, causing an overloading on the muscle-tendinous structures of the knee joint. Thus, the establishment of normal parameters for the muscle function related to that joint in volleyball athletes is necessary. Therefore, the purpose of this study was to assess through isokinetic dynamometry the peak torque, work peak, agonist/antagonist ratio, and fatigue index of the flexor and extensor of the knee among both volleyball athlete population. The isokinetic flexion and extension tests of the knees were performed in the concentric-concentric seat mode at 60 and 300o/sec. velocity in thirty-six athletes (20 under 19-under 21, and 16 under 21). The data allowed to set the parameters for the muscle function of the knee joint among athletes of the 2003 Under 19-Under 21 and Under 21 Brazilian National Team Selection of Male Volleyball. Athletes presented peak torque and work peak values normalized by the body mass to the upper quadriceps to the mean normal values for the athletes and non-athletes populations. Compared to other categories, the under 21 athletes presented significantly higher values for the agonist/antagonist ratio, and peak work ratio of the knee flexors at 60o/sec. velocity. Furthermore, the agonist/antagonist ratio was lower than the reference value expected for both categories, thus characterizing predominance in the extensor musculature over the flexor musculature. The fatigue index was close to what would be expected for the majority of athletes. The present study may be useful as comparison basis for future studies aiming evaluate the isokinetic muscle function in volleyball players.

A Quick and Reliable Procedure for Assessing Foot Alignment in Athletes

BACKGROUND Quick procedures with proper psychometric properties that can capture the combined alignment of the foot-ankle complex in a position that may be more representative of the status of the lower limb during ground contact are essential for assessing a large group of athletes. METHODS The assessed lower limb was positioned with the calcaneus surface facing upward in a way that all of the marks could be seen at the center of the camera display. After guaranteeing maintenance of the foot at 90° of dorsiflexion actively sustained by the athlete, the examiner took the picture of the foot-ankle alignment. RESULTS Intraclass correlation coefficients ranging from 0.82 to 0.93 demonstrated excellent intratester and intertester reliability for the proposed measurements of forefoot, rearfoot, and shank-forefoot alignments. The intraclass correlation coefficient between the shank-forefoot measures and the sum of the rearfoot and forefoot measures was 0.98, suggesting that the shank-forefoot alignment measures can represent the combined rearfoot and forefoot alignments. CONCLUSIONS This study describes a reliable and practical measurement procedure for rearfoot, forefoot, and shank-forefoot alignments that can be applied to clinical and research situations as a screening procedure for risk factors for lower-limb injuries in athletes.

Confiabilidade da mensuração do alinhamento pélvico no plano transverso durante o teste da ponte com extensão unilateral do joelho

BACKGROUND: The bridge test with unilateral knee extension evaluates the stability of the trunk and pelvis. The evaluation of this stability can contribute to the understanding of the occurrence of musculoskeletal injuries. OBJECTIVES: To investigate the intra- and inter-rater reliability of a qualitative analysis and intra-test reliability of a quantitative analysis of transverse plane pelvic alignment during the bridge test with unilateral knee extension. METHOD: Thirty participants (24.73±4.24 years old) were tested. The qualitative analysis was conducted by asking two raters to judge the transverse plane pelvic alignment and its reliability was assessed with the weighted kappa coefficient (kw). The quantitative analysis was conducted by measuring the greatest pelvic tilt angle in transverse plane and its reliability was assessed by use of the intraclass correlation coefficient (ICC); the mean change, which was evaluated using 95% confidence interval of the mean difference (95%CI ) and Bland-Altman plot; and the quantification of measurement variability, which was assessed using standard error of measurement (SEM) and the coefficient of variation of the typical error (CVTE). In addition, the minimal detectable change (MDC95) was determined. RESULTS: The intra-rater reliability ranged from fair to moderate (kw=0.32 to 0.58) and the inter-rater reliability was substantial (kw=0.80). The intra-test reliability was excellent (ICC=0.82), the 95% CI ranged from -0.51o to 1.99o, the SEM was 2.38o and the CVTE was 28.75%. The MDC95 was 6.59o. CONCLUSIONS: The inter-rater reliability was greater than the intra-rater reliability; the intra-test reliability was excellent and showed no systematic or random error.

The Accuracy of the VISA-P Questionnaire, Single-Leg Decline Squat, and Tendon Pain History to Identify Patellar Tendon Abnormalities in Adult Athletes

Study Design Cross-sectional clinical assessment. Background Patellar tendinopathy is not always accompanied by patellar tendon abnormalities (PTAs). Thus, clinical screening tools to help identify patients with patellar tendon pain who have PTAs could enhance clinical decision making and patient prognosis. Objectives To test the diagnostic accuracy of the Victorian Institute of Sport Assessment-Patella (VISA-P) questionnaire, a single-leg decline squat (SLDS), tendon pain history, age, and years of sports participation to identify athletes with symptomatic patellar tendons who have PTAs confirmed on imaging. Methods Data provided by ultrasound examination, the VISA-P questionnaire, the SLDS, tendon pain history, age, and years of sport participation were collected in 43 athletes. A classification and regression tree (CART) model was developed to verify variables associated with PTA occurrence. Likelihood ratios (LRs) were computed for positive and negative tests. Results The SLDS, VISA-P questionnaire, and tendon pain history were associated with PTA occurrence. Athletes with negative results on all 3 tests (CART model) had a lower likelihood of having PTAs (negative LR = 0.3; 95% confidence interval [CI]: 0.2, 0.5). The isolated use of the SLDS or tendon pain history (positive LR = 4.2; 95% CI: 2.3, 7.14 and 4.5; 95% CI: 1.8, 11.1, respectively) had similar influence on probability of PTA presence compared to the CART model (positive LR = 4.1; 95% CI: 2.5, 6.3). Conclusion Although the objective was to investigate a clinical test to identify PTAs, the combined use of the tests had greater accuracy to identify individuals without PTAs. Level of Evidence Diagnosis, level 3b. J Orthop Sports Phys Ther 2016;46(8):673-680. Epub 3 Jul 2016. doi:10.2519/jospt.2016.6192.

Association of Hip and Foot Factors With Patellar Tendinopathy (Jumper's Knee) in Athletes

• BACKGROUND: Investigations on the causes of patellar tendinopathy should consider impairments at the hip and foot/ankle because they are known to influence movement patterns and affect patellar tendon loading. • OBJECTIVES: To investigate hip and foot/ankle impairments associated with patellar tendinopathy in volleyball and basketball athletes using classification and regression tree analysis. • METHODS: In this clinical measurement, cross‐sectional study, 192 athletes were assessed for impairments of the hip and foot/ankle, including shank‐forefoot alignment, dorsiflexion range of motion (ROM), iliotibial band flexibility, passive hip internal rotation ROM, and hip external rotator and hip abductor isometric strength. Athletes with tenderness and/or pain at the inferior pole of the patella were considered to have patellar tendinopathy. Athletes with scores higher than 95 points on the Victorian Institute of Sport Assessment‐patella (VISA‐P), no pain during the single‐leg decline squat, and no history of patellar tendon pain were considered not to have patellar tendinopathy. Classification and regression tree analyses were performed to identify interacting factors associated with patellar tendinopathy. • RESULTS: Interactions among passive hip internal rotation ROM, shank‐forefoot alignment, and hip external rotator and abductor strength identified athletes with and without patellar tendinopathy. The model achieved 71.2% sensitivity and 74.4% specificity. The area under the receiver operating characteristic curve was 0.77 (95% confidence interval: 0.70, 0.84; P<.001). • CONCLUSION: Impairments of the hip and foot/ankle are associated with the presence of patellar tendinopathy in volleyball and basketball athletes. Future studies should evaluate the role of these impairments in the etiology of patellar tendinopathy. • KEY WORDS: decision trees, epidemiology, knee, sports, tendon injury