The effect of hip abductions muscle strength on knee alignment during a single-leg landing in female basketball players / 体力科学

<p>Non-contact anterior cruciate ligament (ACL) injury is one of the most severe knee problems for female athletes. Several studies have reported that the decreased lower limb control of women such as decrease of hip abductions muscle strength increase the risk of ACL injury. Also ACL Injury often occurs as a result of knee valgus collapse during single leg landing or pivoting in sports activities like basketball. Female basketball players often show an excessive knee valgus and hip adduction during the play. The purpose of this study was to analyze the effect of hip abductions muscle strength on knee alignment during a single leg landing. Thirty healthy female basketball players participated in this study. Mean age, height, body weight and plyer career were 17.3 years old±3.7, 162.7cm±17.2, 56.2kg±10.9, 8.9 years±3.8 respectively. All subjects were obtained written consent from after explanation of the procedure. Significant negative correlations showed that greater hip abductor peak torque (hip flexion 0 and 30degrees) exhibited less motion toward the knee valgus direction during single leg landing. And also, dynamic Trendelenburg test showed that all positive reactions cause knee valgus direction. These results suggest keeping proper knee position safety during single leg landing; female basketball player should improve the hip abductions muscle strength. Hip joint control will be a major issue for prevention of the non-contact ACL injury.</p>

Relationship between body mass index and knee alignment using non-radiographic / umbilical method.

Aim: The aim of the research was to investigate the relationship between body mass index and knee alignment angle using non-radiographic methods, and to propose a regression equation to define the relationship.Method: A total of 300 students (200 males, 100 females) of Nnamdi Azikiwe University, Nnewi campus participated in the study. Knee alignment was measured using body landmarks (umbilicus, right knee and right second toe) with a goniometer and calliper; the body mass index was also determined.Result: The male subjects had a mean body mass index of 24.2 kg/m2 and knee alignment angle of 176.5o. The female participants had a mean body mass index of 22.7 kg/m2 and knee alignment angle of 180.9o. Body mass index had no significant relationship with knee alignment in both males and females respectively (r = 0.009, p > 0.05; r = 0.065, p > 0.05). Conclusion: The study showed no significant positive relationship between body mass index and knee alignment, and body mass index is therefore not a good determinant for the control of knee alignment-based knee osteoarthritis.

A prática do futebol acentua os graus de Geno Varo / Does soccer practice stress the degrees of genu varo

Estudos têm mostrado uma varização progressiva entre os períodos de infância e adolescência. Variáveis como idade, peso, ingestão hormonal e vitamínica, ambiente e o treinamento de futebol podem interferir no alinhamento do joelho. OBJETIVOS: A) Comparar o alinhamento do joelho de praticantes e não praticantes de futebol; e B) Determinar associações entre este alinhamento com variáveis antropométricas e neuromotoras da aptidão física. MÉTODOS: A distância intercondilar (DIC) e a intermaleolar (DIM) foram mensuradas em centímetros em 128 adolescentes com idades entre 14 a 17 anos, dentre os quais 65 eram praticantes de futebol e 63 não eram praticantes de tal modalidade. As variáveis antropométricas mensuradas foram peso e estatura, enquanto as neuromotoras inclusas foram agilidade e velocidade. RESULTADOS: Os praticantes de futebol apresentaram graus mais acentuados de joelho varo do que os não jogadores de futebol em todas as idade; entretanto, apenas nos 14 e 17 anos e no grupo total (todas idade juntas) essa diferença foi estatisticamente significativa (p < 0,05). Geno valgo (DIM) tende a ser menor nos praticantes de futebol em todas as idade quando comparados com os não jogadores de futebol; entretanto, tal diferença foi estatisticamente significativa (p < 0,05) apenas nos 17 anos de idade e no grupo total. A DIC nos praticantes de futebol apresentou correlação (p < 0,05) com a agilidade (r = -0,27) e o peso (r = -0,27), enquanto a DIM apresentou correlação (p < 0,05) com o peso (r = 0,26). CONCLUSÃO: Praticantes de futebol mostram um alinhamento do joelho mais acentuado a favor do varismo do que os não praticantes de futebol. Houve associação significativa entre os graus de geno varo e valgo com o peso e a agilidade; nesse sentido, sugere-se mais estudos para explicar essa interessante relação. Os achados do presente estudo suportam a hipótese de que o futebol acentua os graus de geno varo e/ou os sujeitos são selecionados naturalmente para tal prática.

Studies have shown a progressive variation between the childhood and adolescence periods. Variables such as age, weight, vitamin/hormone intake, the environment and soccer training may interfere in the knee alignment. OBJECTIVE: a- to compare the knee alignment in soccer and non-soccer practitioners, and b- to determine associations between this alignment and anthropometric and neuromotor variables. METHODS: The intercondylar (IC) and intermalleolar (IM) distances were measured in centimeters in 128 male aged from 14-17 years, soccer practitioners (n=65) and non-practitioners (n=63). The anthropometric variables measured were: body weight and height, whereas the neuromotor variables included agility and speed. RESULTS: Soccer players revealed a greater degree of genu varum (IC) than non-soccer players in all ages, but just in 14, 17 years-old and total group (all ages together) these differences were statistically significant (p< .05). Genu valgum (IM) tended to be less remarkable in soccer players than in non-soccer players in all ages; however, significant differences were observed only in 17 years and total group (p< .05). The IC distances in soccer players correlated (p< .05) with agility (r= .-27), weight (r= .-27); while IM distances correlated (p< .05) with weight(r=.26). CONCLUSION: Soccer players showed more remarkable genu varum than the non-soccer players. There was a significant association between degrees of varus and valgum with body weight and agility. Such fact deserves further investigation in order to explain this interesting correlation. Present findings support the hypothesis that soccer leads to greater varus and/or this sport naturally selects subjects with a certain degree of varus.

The Analysis of Risk Factors in No Thumb Test in Total Knee Arthroplasty

BACKGROUND: We would like to analyze the risk factors of no thumb test among knee alignment tests during total knee arthroplasty surgery. METHODS: The 156 cases of total knee arthroplasty by an operator from October 2009 to April 2010 were analyzed according to preoperative indicators including body weight, height, degree of varus deformity, and patella subluxation and surgical indicators such as pre-osteotomy patella thickness, degree of patella degeneration, no thumb test which was evaluated after medial prepatella incision and before bone resection (1st test), no thumb test which was evaluated with corrective valgus stress (2nd test, J test), and the kind of prosthesis. We comparatively analyzed indicators affecting no thumb test (3rd test). RESULTS: There was no relation between age, sex, and body weight and no thumb test (3rd test). Patellar sulcus angle (p = 0.795), patellar congruence angle (p = 0.276) and preoperative mechanical axis showed no relationship. The 1st no thumb test (p = 0.007) and 2nd test (p = 0.002) showed significant relation with the 3rd no thumb test. Among surgical indicators, pre-osteotomy patella thickness (p = 0.275) and degeneration of patella (p = 0.320) were not relevant but post-osteotomy patellar thickness (p = 0.002) was relevant to no thumb test (3rd test). According to prosthesis, there was no significance with Nexgen (p = 0.575). However, there was significant correlation between Scorpio (p = 0.011), Vanguard (p = 0.049) and no thumb test (3rd test). Especially, Scorpio had a tendency to dislocate the patella, but Vanguard to stabilize the patella. CONCLUSIONS: No thumb test (3rd test) is correlated positively with 1st test, 2nd test, and post-osteotomy patella thickness. Therefore, the more patella osteotomy and the prosthesis with high affinity to patellofemoral alignment would be required for correct patella alignment.

VALIDATION OF A TWO-DIMENSIONAL MOTION ANALYSIS TECHNIQUE FOR QUANTIFYING DYNAMIC KNEE VALGUS DURING A DROP LANDING BY COMPARISONS TO DATA FROM THREE-DIMENSIONAL ANALYSIS / 体力科学

Dynamic knee valgus is considered a risk factor of non-contact anterior cruciate ligament (ACL) injury. To identify athletes at a higher risk, we developed a two-dimensional (2D) video-based screening test that determines hip abductor function as well as dynamic hindfoot and knee valgus. The purpose of this study was to validate the accuracy of the indices for dynamic knee valgus derived knee-in distance (KID) and hip-out distance (HOD) from the 2D-video.Twenty healthy university students agreed to participate in this study. Subjects were asked to step off a 30-cm box and land on one leg. This procedure was recorded simultaneously using a 2D video camera in the frontal plane and the Vicon motion capture system. Pearson's correlations examined associations between KID, KID normalized by height (KID/H), HOD, as well as HOD normalized by height (HOD/H) and 3D-valgus (knee valgus) or 3D-IR (tibial internal rotation).Significant correlations were found between the KID and 3D-valgus (r=0.72, p<0.01) and KID/H and 3D-valgus (r=0.73, p<0.01). Associations were not significant between KID and 3D-IR (r=0.08) and between KID/H and 3D-IR (r=0.03). A positive moderate correlation between HOD and 3D-valgus (r=0.46, p<0.05) and HOD/H and 3D-valgus (r=0.50, p<0.05), as well as a negative moderate correlations between HOD and 3D-IR (r=-0.52, p<0.05) and between HOD/H and 3D-IR (r=-0.51, p<0.05) were also observed.We conclude that KID is a reliable alternative for the 3D-valgus and the HOD is for the 3D-valgus and tibial external rotation.

ASSOCIATION BETWEEN HIP AND HINDFOOT DYNAMIC ALIGNMENT AND DYNAMIC KNEE VALGUS IN HIGH SCHOOL FEMALE BASKETBALL PLAYERS / 体力科学

Dynamic knee valgus is considered a risk factor of noncontact ACL injuries. The aim of this study was to determine the association between hip and hindfoot dynamic alignment and dynamic knee valgus.This cross-sectional study involved 88 high school female basketball players (175 legs). Subjects performed single-leg squatting and drop landing which provided a hip-out distance (HOD) and a knee-in distance (KID) via 2D video images. Hip and hindfoot dynamic alignment was evaluated by a dynamic Trendelenburg test (DTT) and a heel-floor test (HFT), respectively, during squatting and landing.The DTT-positive group (dynamic hip mal-alignment with lower non-weightbearing pelvis) demonstrated greater HOD and KID values for both squatting (p＜0.001) and landing (p＜0.001) than the DTT-negative group. The HFT-positive group (5^o or greater hindfoot valgus) demonstrated greater KID values for both squatting (p＜0.01) and landing (p＜0.001), but smaller HOD value for squatting (p＜0.01) than the HFT-negative group.In conclusion, dynamic hip mal-alignment may be associated with both greater HOD and KID, but hindfoot valgus only with greater KID.