This study examined the relationship between hip strength and hip, pelvis, and trunk kinematics in healthy runners. Whole body kinematic data were collected while subjects ran in the laboratory. Isometric hip abduction, flexion, external rotation, and internal rotation torques were measured bilaterally using a dynamometer. Subjects were divided into strong and weak groups for each muscle strength parameter. Differences in hip, pelvis, and trunk motion were then examined using independent sample t-tests. Pearson correlation coefficients were used to assess these relationships for all subjects. Most notably, runners with weak abductors displayed greater hip adduction and pelvic rotation compared to the strong abductor group, while runners with weak external rotators displayed greater trunk rotation compared to the strong external rotator group. Moderate, negative correlations were observed for the above relationships. While data from this study help clarify the relationship between hip strength and running kinematics, no causal conclusions can be made.

Patellofemoral pain syndrome (PFPS) is the most common injury in runners and has a significant female sex bias. Current evidence suggests that several proximal factors, including hip muscle strength, hip muscle activation, and hip kinematics during running, play a large role in the development of PFPS, particularly in females. However, the relationships between these variables are unclear. A better understanding of these relationships in both males and females could help clinicians develop targeted interventions for this syndrome. Thus, this dissertation is comprised of four studies aimed to better understand the relationships between these risk factors. The first study investigated whether there are any relationships between hip muscle strength and hip muscle activation during running. Overall, hip muscle strength and hip muscle activity during running do not appear to be strongly related. The second study used a multiple regression approach to look for predictors of hip adduction and hip internal rotation during running. Sex was a significant predictor in both models, and running speed, static subtalar inversion range of motion, and gluteus maximus amplitude were significant predictors in the hip adduction model. The third study examined the effect of decreasing hip abduction strength on running kinematics and hip muscle EMG. After the fatigue protocol, there were no changes in gluteus medius amplitude or timing, and no changes in hip kinematics during running. However, there were some changes in kinematics, particularly at the trunk, as well as differences in gluteus maximus and tensor fascia latae activation. Finally, the fourth study used an alternative biomechanical method called continuous relative phase (CRP) to investigate the effect of sex and decreasing hip abduction strength on CRP variability at the hip. Decreasing hip abduction strength increased frontal plane CRP variability from 20-40% of stance phase, primarily in females, and females demonstrated less CRP variability than males in the frontal plane and transverse planes. Overall, the results from this study improve our understanding of the relationships between hip strength, hip muscle activation, and hip kinematics during running in both males and females, which may have implications for knee injury rehabilitation strategies. This dissertation includes unpublished co-authored material.

Many children with developmental disabilities (DD) have physical impairments and limitations in their participation. Rehabilitation research often focuses on either physical impairments or participation restrictions, when both need to be investigated. The purposes of these two studies were to evaluate an at home therapist directed video game balance training intervention on balance, gait velocity (GV), hip strength and activities of children with DD. The pilot study was a single-subject non-concurrent multiple baseline design. Balance measures included: weight bearing symmetry; center of pressure area and velocity; time to boundary mean minima and standard deviation; and timed up and go. The participant’s enjoyment and perceived difficulty was also explored. Five children (7 to 10 years) with cerebral palsy (CP) participated in a 6 week, 30 minute intervention 3 times per week, with four preselected balance games. Minimal improvements were found in balance, GV, and hip strength, and participants reported the intervention enjoyable and challenging. Three of five participants had significant increases in activities, as measured by the Activities Scale for Kids (ASK). The second study expanded on pilot study results and included 5 children (5 to 10 years) with different diagnoses. Another non-concurrent multiple baseline design was utilized, and the same measures of balance were used except single leg stance time was substituted for timed up and go. No changes were made to the intensity of intervention, but two games were added to the repertoire. There were minimal changes in balance and hip strength; and no changes were found in the ASK. A majority of participants increased GV, and reported the intervention was enjoyable and challenging. Positive changes were found in the combined results for: center of pressure area with eyes open and closed; time to boundary mean minima with eyes closed in the anterior-posterior direction; and GV. These studies suggest this intervention was insufficient to make improvements in the majority of balance measurements and hip strength for children with DD. Increased activities in children with CP were found in the pilot study. These results suggest video game balance training alone for children with DD was insufficient to demonstrate clinically meaningful change. KEYWORDS: Balance, Developmental Disabilities, Gait Velocity, Hip Strength, Activities and Participation

No description available.

Background: Basketball is one of the most popular physical activities in the world and lower limb joints are constantly exposed to physical stress. Girls have been shown to perform athletic movement with an adverse biomechanical profile with high risk for injury. We need more knowledge about how we can introduce motion control training in their regular training program in a simple and uncomplicated way. This study aims to examine the effect and experience of a preventive biomechanics program for female adolescent basketball players. Method: Twelve female basketball players, 12-13 years old, participated in this uncontrolled pilot intervention study. The seven weeks intervention included a 12 minutes preventive biomechanics program twice a week and a daily 2 minutes homes exercise. Performance on the Y-Balance test (YBT), a motor control test battery (MCTB) and hip abductor strength (HAS) was assessed before and after the intervention. Their experience was evaluated using a questionnaire after the intervention. Result: The participants improved significantly in all three outcome measures, YBT, MCTB and HAS after completed intervention. All participants indicated in the questionnaire that they were positive about the intervention and that they would choose to participate again. Conclusion: A seven week preventive biomechanics program twice a week showed positive effects on both motor control exercises and subjective experience among female adolescent basketball players. These results indicate that the training intervention was well accepted and had positive effects on balance, trunk motor control and hip muscle strength. This may in turn have positive effect on injury prevention. However, that needs to be investigated in future RCT with longer follow up time.

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-04-17T14:19:34Z No. of bitstreams: 1 DissAFM.pdf: 2100270 bytes, checksum: 7862a25fb8beaa0e521e184d6e55def3 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-04-17T17:37:58Z (GMT) No. of bitstreams: 1 DissAFM.pdf: 2100270 bytes, checksum: 7862a25fb8beaa0e521e184d6e55def3 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-04-17T17:38:09Z (GMT) No. of bitstreams: 1 DissAFM.pdf: 2100270 bytes, checksum: 7862a25fb8beaa0e521e184d6e55def3 (MD5) / Made available in DSpace on 2017-04-17T17:44:34Z (GMT). No. of bitstreams: 1 DissAFM.pdf: 2100270 bytes, checksum: 7862a25fb8beaa0e521e184d6e55def3 (MD5) Previous issue date: 2017-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Purpose: Kinematic changes have been correlated with different lower limb injuries, being some of these injuries more common in female athletes, and a likely predisposing factor to these changes is hip and trunk muscle weakness. Thus, the aim of this study was to evaluate the correlation among trunk and hip strength with three-dimensional trunk and lower-limb kinematics during a jump-landing task in female recreational athletes. Methods: Twenty-three healthy women recreational athletes aged between 18 and 35 years underwent evaluation of hip abductor, hip extensor, and lateral trunk muscle strength by manual dynamometry and three-dimensional trunk and lower-limb kinematics during the landing phase of a single-leg drop vertical jump. Pearson's correlation coefficients (r) were calculated to establish the relationship between hip and trunk strength and trunk, hip, and knee movements. Results: Greater hip extensor strength was found to be significantly associated with greater trunk flexion at initial contact. No significant correlations were found among the strength data and the peak values of kinematics during the landing phase. Conclusion: Considering that the greater trunk flexion is related to lower anterior cruciate ligament (ACL) load, patellofemoral stress and patellar tendon force, hip extensor muscle strengthening may be important to prevent and rehabilitate ACL injury, patellofemoral pain, and patellar tendinopathy. / Objetivo: Alterações da cinemática têm sido correlacionadas com diferentes lesões nos membros inferiores, sendo algumas dessas lesões mais comuns em mulheres atletas, e um provável fator predisponente para essas alterações é a fraqueza dos músculos do quadril e do tronco. Assim, o objetivo deste estudo foi avaliar a correlação entre a força do tronco e do quadril com a cinemática tridimensional de tronco e membros inferiores durante uma tarefa de aterrissagem de um salto em mulheres atletas recreacionais. Métodos: Vinte e três mulheres sadias atletas recreacionais com idade entre 18 e 35 anos foram submetidos a avaliação da força dos músculos abdutores de quadril, extensores do quadril e inclinadores laterais do tronco através de um dinamômetro manual e da cinemática tridimensional de tronco e membros inferiores durante a fase de aterrissagem de uma queda e salto vertical unipodal (single-leg drop vertical jump). Os coeficientes de correlação de Pearson (r) foram calculados para estabelecer a relação entre a força do quadril e do tronco e os movimentos do tronco, quadril e joelho. Resultados: Maior força extensora do quadril foi encontrada significativamente associada com maior flexão do tronco no contato inicial. Não foram encontradas correlações significativas entre os dados de força e os valores de pico da cinemática durante a fase de aterrissagem. Conclusão: Considerando que a maior flexão do tronco está relacionada à carga do ligamento cruzado anterior (ACL), ao estresse patelofemoral e a força do tendão patelar, o fortalecimento dos músculos extensores do quadril pode ser importante para prevenir e reabilitar a lesão do LCA, dor femoropatelar e tendinopatia patelar.

Inledning: Muskelstyrka i höftregionen är en viktig fysisk färdighet inom fotboll dels ur ett prestationsperspektiv, dels för skadeprevention. Trots detta saknas normativa isometriska styrkevärden för höftadduktorer och - abduktorer hos damfotbollsspelare. Syfte: Syftet med denna tvärsnittsstudie var att undersöka den isometriska höftstyrkan i adduktion, unilateralt och bilateralt, samt höftabduktion unilateralt med en handhållen dynamometer hos skadefria damfotbollsspelare. Metod: 29 friska damfotbollsspelare på elitnivå inkluderades i studien. Den isometriska höftstyrkan mättes vid ett tillfälle på försäsongen med en handhållen dynamometer. Höftadduktion och -abduktion mättes unilateralt i en sidliggande position och den bilaterala höftadduktorstyrkan mättes i ett squeeze-test i en ryggliggande position. Ett tillägg av en extern fixation av dynamometern applicerades vid testtillfället. Resultat: Styrkevärden (medelvärde, SD ±) var: höftabduktion dominant ben 1,94 ± 0,3 Nm/kg, icke-dominant ben 1,81± 0,3 Nm/kg, höftadduktion dominant ben 1,61 ± 0,3 Nm/kg, icke-dominant ben 1,51 ± 0,3 Nm/kg, squeeze-test 4,11 ± 0,5 N. Styrkekvot adduktion/abduktion var 0,83 dominant ben och 0,84 icke-dominant ben. Det dominanta benet var signifikant starkare (p<0,05) i både höftadduktion och -abduktion, 7 % respektive 8 %. Konklusion: För damfotbollsspelare var det dominanta benet signifikant starkare i både höftadduktion och -abduktion. Höftabduktorerna var signifikant starkare än adduktorerna i både det dominanta och icke-dominanta benet med en styrkekvot adduktorerna/abduktorerna på 0,83 respektive 0,84. / Introduction: Hip strength is an important physical factor in soccer for both performance and for injury prevention. Despite this normative isometric strength values are lacking for hip adduction and abduction in healthy women’s soccer players. Aim: The aim of this cross-sectional study was to examine the isometric hip strength in adduction, unilateral and bilateral, and hip abduction unilateral with a handheld dynamometer in healthy women's soccer players. Methods: 29 healthy female elite soccer players were included in the study. The isometric hip strength was measured one time in the pre-season with a hand-held dynamometer. Hip adduction and abduction were measured unilaterally in a side lying position and the bilateral hip adductor strength was measured in a squeeze test in a supine position. An addition of an external fixation of the dynamometer was applied during testing. Results: Strength values (mean, SD ±) were: hip abduction dominant leg 1,94 ± 0,3 Nm/kg, non-dominant leg 1,81± 0,3 Nm/kg, hip adduction dominant leg 1,61 ± 0,3 Nm/kg, non-dominant leg 1,51 ± 0,3 Nm/kg, squeeze-test 4.11 ± 0.5 N. The strength ratio of adduction/abduction were 0,83 dominant leg and 0,84 non-dominant leg. The dominant leg was significantly stronger (p<0,05) in both hip abduction and adduction, 7 % and 8 %, respectively. Conclusion: For women’s soccer players the dominant leg was significantly stronger in both hip abduction and adduction. The hip abductors were significantly stronger than the adductors in both the dominant and non-dominant leg with a strength ratio adductor/abductor 0,83 and 0,84 respectively.

No description available.