Altered hip muscle forces during gait in people with patellofemoral osteoarthritis

Objectives: The study aimed to (1) assess whether higher vasti (VASTI), gluteus medius (GMED), gluteus maximus (GMAX) and gluteus minimus (GMIN) forces are associated with participant characteristics (lower age, male gender) and clinical characteristics (lower radiographic disease severity, lower symptom severity and higher walking speed); and (2) determine whether hip and knee muscle forces are lower in people with patellofemoral joint (PFJ) osteoarthritis (OA) compared to those without PFJ OA. Design: Sixty participants with PFJ OA and 18 (asymptomatic, no radiographic OA) controls ≥40 years were recruited from the community or via referrals. A three-dimensional musculoskeletal model was used in conjunction with optimisation theory to calculate lower-limb muscle forces during walking. Associations of peak muscle forces with participant and clinical characteristics were conducted using Pearson's r or independent t-tests and between-group comparisons of mean peak muscle forces performed with walking speed as a covariate. Results: Peak muscle forces were not significantly associated with participant, symptomatic or radiographic-specific characteristics. Faster walking speed was associated with higher VASTI muscle force in the PFJ OA (r = 0.495; P < 0.001) and control groups (r = 0.727; P = 0.001) and higher GMAX muscle force (r = 0.593; P = 0.009) in the control group only. Individuals with PFJ OA (N = 60) walked with lower GMED and GMIN muscle forces than controls (N = 18): GMED, mean difference 0.15 [95% confidence interval (CI): 0.01 to 0.29] body weight (BW); GMIN, 0.03 [0.01 to 0.06] BW. No between-group differences were observed in VASTI or GMAX muscle force: VASTI, 0.10 [-0.11 to 0.31] BW; GMAX, 0.01 [-0.11 to 0.09] BW. Conclusion: Individuals with PFJ OA ambulate with lower peak hip abductor muscle forces than their healthy counterparts

Follow-up of loci from the International Genomics of Alzheimer's Disease Project identifies TRIP4 as a novel susceptibility gene

To follow-up loci discovered by the International Genomics of Alzheimer's Disease Project, we attempted independent replication of 19 single nucleotide polymorphisms (SNPs) in a large Spanish sample (Fundació ACE data set; 1808 patients and 2564 controls). Our results corroborate association with four SNPs located in the genes INPP5D, MEF2C, ZCWPW1 and FERMT2, respectively. Of these, ZCWPW1 was the only SNP to withstand correction for multiple testing (P=0.000655). Furthermore, we identify TRIP4 (rs74615166) as a novel genome-wide significant locus for Alzheimer's disease risk (odds ratio=1.31; confidence interval 95% (1.19-1.44); P=9.74 × 10 - 9)

Action planning in young children's tool use

Contains fulltext : 55864.pdf (publisher's version ) (Closed access)Tool use consists of at least two coupled phases of activities, involving multi-step problem solving. It therefore provides an interesting window on the development of planning in goal-directed behavior. This study investigated 2-year-olds’ and 3-year-olds’ hand use in picking up and subsequently using a tool for displacing a target-object towards a specified goal location. The children had to use a stick (Experiment 1; N = 41 in total) or a cane (hooked stick) that was lying in varying starting orientations (Experiment 2; N = 32 in total). Age differences were found in the way goal-related information in combination with tool-related information influenced the choice of which hand to use in different phases of the task. A view on action planning is developed as a dynamic action-selection process for which actions to take. This process integrates factors that are internal to the child's action system (e.g. motor preferences and dexterity) with external (i.e. sensory) sources of information.14 p

Bridging the representational gap in the dynamic systems approach to development

We describe the relationship between the dynamic systems approach to development and a recent approach to the dynamics of representational states - the dynamic field approach. Both approaches share an emphasis on the concepts of stability (attractor states), instability (especially bifurcations), soft-assembly and flexibility. But the dynamic field approach adds the concept of 'activation' to capture the strength with which behaviorally relevant information is specified. By explicitly linking these dynamic systems approaches, we allow for more direct comparisons between dynamic systems theory and connectionism. We note three current differences between these two approaches to development: (1) the notion of stability is central to how representational states are conceptualized in the dynamic field approach; (2) the dynamic field approach is more directly concerned with the sensorimotor origins of cognition; and (3) the dynamic approach is less advanced with regard to learning. We conclude that proponents of the two approaches can learn from the respective strengths of each approach. We suspect these differences will largely disappear in the next 20 years

Arremessar por cima do ombro e a distância percorrida pelo implemento Overarm throw and the distance traveled by the implement

A habilidade de arremessar por cima do ombro tem sido bastante estudada, observando-se a velocidade do implemento, porém enquanto muitas tarefas têm como objetivo arremessar o mais longe possível, a distância percorrida pelo objeto ainda não tem sido investigada. O objetivo deste estudo foi verificar se existe relação entre o estágio de desenvolvimento motor nesta habilidade e a distância percorrida pelo implemento e observar diferenças entre os gêneros masculino e feminino; 50 crianças, com idade entre 7-8 anos, de ambos os gêneros, procedentes de Piracicaba - SP foram analisadas enquanto arremessavam uma bola de tênis de campo, o mais longe possível. Cada criança realizou três arremessos intercalados e foi filmada com duas câmeras mini DV, tanto em vista lateral quanto posterior, enquanto arremessava. O nível de desenvolvimento das crianças foi classificado, utilizando-se uma sequência de desenvolvimento e a distância percorrida pela bola foi registrada. Foi encontrada correlação significativa entre o nível do desenvolvimento e a distância atingida. Diferenças entre os gêneros foram observadas: os meninos encontravam-se em níveis desenvolvimentais mais avançados em todas as ações e alcançaram maiores distâncias. Assim, o nível de desenvolvimento desta habilidade mostrou-se importante para o alcance de seu objetivo (arremessar mais longe). Sugere-se que o nível de habilidade é influenciado pelo meio ambiente e que oportunidades de movimento devem ser providenciadas para auxiliar o desenvolvimento integral da criança.<br>Overarm throwing skill has been widely studied regarding the farthest throwing distance analysing the velocity of the implement; however the object's distance has not been investigated. The aim of this study was to verify if there is a relationship between the skill development and the distance reached by the object and to observe differences between genders. Fifty children, ages 7-8 years, both genders, from Piracicaba - SP, were analyzed while throwing a tennis ball as far as they could. Each child had three attempts. They were filmed with two mini DV cameras, from both side and rear views while performing. Children's movements were categorized using a developmental sequence and the distance covered by the ball was register. A positive correlation was found between the developmental level and the ball distance. Gender differences were observed; boys were in a more advanced levels in all actions and had farther throwing distances. So, developmental level of this skill was important to reach the task goal (throwing as far as possible). It is suggested that skill level is influenced by the environment and movement opportunities must be provided in order to help the children's global development