The main purpose of this study was to investigate the effects of gender on different categories of tenth grade students&#039 / misconceptions about force and motion. The Force Concept Inventory Test (FCI), Mechanics Baseline Test (MBT), Physics Attitude Scale (PAS) and Experience Questionnaire About Force and Motion (EQFM) were developed by the researcher to assess students&#039 / misconceptions, achievement, attitudes, and experiences, respectively. There were nine dependent (students&#039 / total scores on the FCI and their scores on eight misconception categories (Kinematics, Impetus, Active Force, Action/Reaction Pairs, Concatenation of Influences, Other Influences on Motion, Resistance and Gravity)) and six independent (students&#039 / gender, MBT scores, attitude, experience, school type and age) variables involved in this study. This study was conducted with 10 schools / 20 classes / total of 651 10th grade high school students in the academic year of 2002-2003. For each school, two classes were used in the study. MBT, PAS, FCI and EQFM were administered. Findings of the FCI and MBT indicated that general performances of the subjects were relatively low and many students have misconceptions in interpreting force and motion. The statistical results indicated that gender difference is effective on students&#039 / misconceptions in force and motion. When the data were analyzed using MANOVA, gender difference was observed on the collective dependent variables of scores on total FCI, and on misconception categories of Impetus, Active Force, Resistance and Gravity in favor of males although there were no significant difference on scores of both groups on the other categories of misconceptions. Moreover, when the same data were analysed using MANCOVA, while controlling students&#039 / age, attitude, experience, achievement scores, and school types, observed difference on the misconception categories of Active Force and Resistance were disappeared.

Existe uma alta incidência de desigualdade de membros inferiores na população geral, podendo ser do tipo estrutural, onde existe diferença no comprimento de estruturas ósseas, ou funcional, como resultado de alterações mecânicas dos membros inferiores (MMII). A desigualdade pode ainda ser classificada quanto a sua magnitude, sendo discreta, moderada, ou grave. São muitos os métodos antropométricos utilizados para avaliar a desigualdade, entre os mais usados estão os métodos clínicos, como o uso de fita métrica para medir a distância entre duas saliências ósseas. Além destes, os métodos radiográficos também podem ser usados, porém com menor freqüência devido ao custo elevado e exposição à radiação. As desigualdades discretas têm sido associadas especificamente à fratura por estresse, dor lombar e osteoartrite. Quando uma desigualdade está presente em indivíduos cuja sobrecarga mecânica é acentuada pela sua prática profissional, diária ou recreativa, estas desordens podem se manifestar precoce e gravemente. O objetivo deste estudo foi comparar diversas medidas antropométricas de comprimento de MMII usadas na prática clínica com a escanometria em corredores, e estudar a Força Reação do Solo durante a marcha e a corrida de corredores com desigualdade estrutural discreta de membros inferiores. Observou-se que a presença de desigualdade de membros inferiores foi associada à maior incidência de sintomas nos quadris e joelhos nos corredores. As medidas clínicas EIAS/MM (R=0,96; p=0,000), EIAS/ML (R=0,97; p=0,000), Crista/MM (R=0,95; p=0,000) e Umbigo/MM (R=0,92; p=0,000) apresentaram alta correlação com a escanometria. Entretanto, somente a medida clínica Umbigo/MM (0,8 ± 0,6 cm; 0,8 ± 0,5%) detectou desigualdade absoluta e normalizada entre os membros semelhante à escanometria (0,6 ± 0,5 cm; 0,8 ± 0,6%). Observou-se que quanto maior a desigualdade, maior a sobrecarga em ambos MMII, cargas estas capazes de causar em longo prazo desordens ortopédicas. Os sujeitos com desigualdade de 0,5 a 2,0 cm, durante o andar, apresentaram no MI menor maiores valores de Fzmin (0,56 ± 0,08 PC); e maiores valores de Fz2 e PO no MI menor durante o correr (2,48 ± 0,22 PC; 17,18 ± 3,35 PC/s). E os sujeitos com desigualdade de 1,0 a 2,2 cm apresentaram no MI maior uma menor Taxa de Crescimento 1 (9,19 ± 1,49 PC/s) em comparação ao controle (10,44 ± 1,72 PC/s) durante o andar; maiores valores de Fz1 no MI maior (1,70 ± 0,17 PC) em relação ao controle (1,57 ± 0,16PC), e ainda maiores valores de Fz2 e PO no MI menor (2,55 ± 0,22 PC; 17,07 ± 3,31 PC/s) durante o correr. No entanto, os sujeitos com desigualdade discreta de membros inferiores apresentaram a marcha e a corrida simétricas de acordo com os valores obtidos pelo Índice de Simetria Absoluto das variáveis da FRS vertical e horizontal. / There is a high incidence of leg length discrepancy (LLD) in general population, which could be structural, when the difference occurs in bone structures, or functional, as a result of mechanical changes at the lower limbs. The discrepancy can also be classified by its magnitude, being mild, intermediate, or severe. Many anthropometric methods are used to evaluate discrepancy, however the most common are clinical methods, which use a tape to measure the distance between two bone landmarks. Radiographic methods can also be used, although they are characterized by high cost and radiation exposure. Mild LLD has been associated with stress fractures, lower back pain and osteoarthritis. When the discrepancy occurs in subjects whose mechanical loads are increased by their professional, daily or recreational activities, these disorders might appear early and severely. The aim of this study was to compare several anthropometric measurements of LLD used in clinical practice with the scanogram in runners, and to study the ground reaction forces during gait and running in runners with mild and structural LLD. Results demonstrated an association between LLD and higher incidence of symptoms in runners\' hips and knees. Clinical measures ASIS/MM (R=0.96; p=0.000), ASIS/LM (R=0.97; p=0.000), Crest/MM (R=0.95; p=0.000) and Umbilicus/MM (R=0.92; p=0.000) presented high correlation with scanogram. Although, only the clinical measurement Umbilicus/MM (0.8 ± 0.6 cm; 0.8 ± 0.5%) detected absolute and relative discrepancy between lower limbs similar to that detected with scanogram (0.6 ± 0.5 cm; 0.8 ± 0.6%). Results also showed that increasing discrepancy leads to overloads in both lower limbs, which may lead to orthopedic disorders after extended periods. Subjects with mild LLD of 0.5 to 2.0 cm presented higher values of Fzmin (0.56 ± 0.08 BW) at the shorter limb during gait, and higher values of Fz2 and PO at the shorter limb (2.48 ± 0.22 BW; 17.18 ± 3.35 BW/s) during running. Subjects with mild discrepancy of 1.0 to 2.2 cm presented a smaller rate of load 1 (9.19 ± 1.49 BW/s) at the longer limb during gait in comparison to control subjects (10.44 ± 1.72 BW/s), and higher values of Fz1 at the longer limb during running (1.70 ± 0,17BW ) relative to control subjects (1.57 ± 0.16PC). Subjects with mild discrepancy also showed higher values of Fz2 and PO at the shorter limb (2.55 ± 0.22 BW; 17.07 ± 3.31 BW/s). Nevertheless, subjects with mild LLD displayed symmetrical gait and running according to values obtained by Absolute Symmetric Index of vertical and horizontal GRF variables.

Existe uma alta incidência de desigualdade de membros inferiores na população geral, podendo ser do tipo estrutural, onde existe diferença no comprimento de estruturas ósseas, ou funcional, como resultado de alterações mecânicas dos membros inferiores (MMII). A desigualdade pode ainda ser classificada quanto a sua magnitude, sendo discreta, moderada, ou grave. São muitos os métodos antropométricos utilizados para avaliar a desigualdade, entre os mais usados estão os métodos clínicos, como o uso de fita métrica para medir a distância entre duas saliências ósseas. Além destes, os métodos radiográficos também podem ser usados, porém com menor freqüência devido ao custo elevado e exposição à radiação. As desigualdades discretas têm sido associadas especificamente à fratura por estresse, dor lombar e osteoartrite. Quando uma desigualdade está presente em indivíduos cuja sobrecarga mecânica é acentuada pela sua prática profissional, diária ou recreativa, estas desordens podem se manifestar precoce e gravemente. O objetivo deste estudo foi comparar diversas medidas antropométricas de comprimento de MMII usadas na prática clínica com a escanometria em corredores, e estudar a Força Reação do Solo durante a marcha e a corrida de corredores com desigualdade estrutural discreta de membros inferiores. Observou-se que a presença de desigualdade de membros inferiores foi associada à maior incidência de sintomas nos quadris e joelhos nos corredores. As medidas clínicas EIAS/MM (R=0,96; p=0,000), EIAS/ML (R=0,97; p=0,000), Crista/MM (R=0,95; p=0,000) e Umbigo/MM (R=0,92; p=0,000) apresentaram alta correlação com a escanometria. Entretanto, somente a medida clínica Umbigo/MM (0,8 ± 0,6 cm; 0,8 ± 0,5%) detectou desigualdade absoluta e normalizada entre os membros semelhante à escanometria (0,6 ± 0,5 cm; 0,8 ± 0,6%). Observou-se que quanto maior a desigualdade, maior a sobrecarga em ambos MMII, cargas estas capazes de causar em longo prazo desordens ortopédicas. Os sujeitos com desigualdade de 0,5 a 2,0 cm, durante o andar, apresentaram no MI menor maiores valores de Fzmin (0,56 ± 0,08 PC); e maiores valores de Fz2 e PO no MI menor durante o correr (2,48 ± 0,22 PC; 17,18 ± 3,35 PC/s). E os sujeitos com desigualdade de 1,0 a 2,2 cm apresentaram no MI maior uma menor Taxa de Crescimento 1 (9,19 ± 1,49 PC/s) em comparação ao controle (10,44 ± 1,72 PC/s) durante o andar; maiores valores de Fz1 no MI maior (1,70 ± 0,17 PC) em relação ao controle (1,57 ± 0,16PC), e ainda maiores valores de Fz2 e PO no MI menor (2,55 ± 0,22 PC; 17,07 ± 3,31 PC/s) durante o correr. No entanto, os sujeitos com desigualdade discreta de membros inferiores apresentaram a marcha e a corrida simétricas de acordo com os valores obtidos pelo Índice de Simetria Absoluto das variáveis da FRS vertical e horizontal. / There is a high incidence of leg length discrepancy (LLD) in general population, which could be structural, when the difference occurs in bone structures, or functional, as a result of mechanical changes at the lower limbs. The discrepancy can also be classified by its magnitude, being mild, intermediate, or severe. Many anthropometric methods are used to evaluate discrepancy, however the most common are clinical methods, which use a tape to measure the distance between two bone landmarks. Radiographic methods can also be used, although they are characterized by high cost and radiation exposure. Mild LLD has been associated with stress fractures, lower back pain and osteoarthritis. When the discrepancy occurs in subjects whose mechanical loads are increased by their professional, daily or recreational activities, these disorders might appear early and severely. The aim of this study was to compare several anthropometric measurements of LLD used in clinical practice with the scanogram in runners, and to study the ground reaction forces during gait and running in runners with mild and structural LLD. Results demonstrated an association between LLD and higher incidence of symptoms in runners\' hips and knees. Clinical measures ASIS/MM (R=0.96; p=0.000), ASIS/LM (R=0.97; p=0.000), Crest/MM (R=0.95; p=0.000) and Umbilicus/MM (R=0.92; p=0.000) presented high correlation with scanogram. Although, only the clinical measurement Umbilicus/MM (0.8 ± 0.6 cm; 0.8 ± 0.5%) detected absolute and relative discrepancy between lower limbs similar to that detected with scanogram (0.6 ± 0.5 cm; 0.8 ± 0.6%). Results also showed that increasing discrepancy leads to overloads in both lower limbs, which may lead to orthopedic disorders after extended periods. Subjects with mild LLD of 0.5 to 2.0 cm presented higher values of Fzmin (0.56 ± 0.08 BW) at the shorter limb during gait, and higher values of Fz2 and PO at the shorter limb (2.48 ± 0.22 BW; 17.18 ± 3.35 BW/s) during running. Subjects with mild discrepancy of 1.0 to 2.2 cm presented a smaller rate of load 1 (9.19 ± 1.49 BW/s) at the longer limb during gait in comparison to control subjects (10.44 ± 1.72 BW/s), and higher values of Fz1 at the longer limb during running (1.70 ± 0,17BW ) relative to control subjects (1.57 ± 0.16PC). Subjects with mild discrepancy also showed higher values of Fz2 and PO at the shorter limb (2.55 ± 0.22 BW; 17.07 ± 3.31 BW/s). Nevertheless, subjects with mild LLD displayed symmetrical gait and running according to values obtained by Absolute Symmetric Index of vertical and horizontal GRF variables.