Keep looking ahead? Re-direction of visual fixation does not always occur during an unpredictable obstacle avoidance task

Visual information about the environment, especially fixation of key objects such as obstacles, is critical for safe locomotion. However, in unpredictable situations where an obstacle suddenly appears it is not known whether central vision of the obstacle and/or landing area is required or if peripheral vision is sufficient. We examined whether there is a re-direction of visual fixation from an object fixated ahead to a suddenly appearing obstacle during treadmill walking. Furthermore, we investigated the temporal relationship between the onset of muscle activity to avoid the obstacle and saccadic eye and head movements to shift fixation. Eight females (mean SD; age = 24.8 2.3 years) participated in this experiment. There were two visual conditions: a central vision condition where participants fixated on two obstacles attached to a bridge on the treadmill and a peripheral vision condition where participants fixated an object two steps ahead. There were two obstacle release conditions: only an obstacle in front of the left foot was released or an obstacle in front of either foot could be released. Only trials when the obstacle was released in front of the left foot were analyzed such that the difference in the two obstacle conditions was whether there was a choice of which foot to step over the obstacle. Obstacles were released randomly in one of three phases during the step cycle corresponding to available response times between 219 and 462 ms. We monitored eye and head movements along with muscle activity and spatial foot parameters. Performance on the task was not different between vision conditions. The results indicated that saccades are rarely made (< 18% of trials) and, when present, are initiated ∼ 350 ms after muscle activity for limb elevation, often accompanied by a downward head movement, and always directed to the landing area. Therefore, peripheral vision of a suddenly appearing obstacle in the travel path is sufficient for successful obstacle avoidance during locomotion: visual fixation is generally not re-directed to either the obstacle or landing area

Postural development in school children: a cross-sectional study

BACKGROUND: Little information on quantitative sagittal plane postural alignment and evolution in children exists. The objectives of this study are to document the evolution of upright, static, sagittal posture in children and to identify possible critical phases of postural evolution (maturation). METHODS: A total of 1084 children (aged 4–12 years) received a sagittal postural evaluation with the Biotonix postural analysis system. Data were retrieved from the Biotonix internet database. Children were stratified and analyzed by years of age with n = 36 in the youngest age group (4 years) and n = 184 in the oldest age group (12 years). Children were analyzed in the neutral upright posture. Variables measured were sagittal translation distances in millimeters of: the knee relative to the tarsal joint, pelvis relative to the tarsal joint, shoulder relative to the tarsal joint, and head relative to the tarsal joint. A two-way factorial ANOVA was used to test for age and gender effects on posture, while polynomial trend analyses were used to test for increased postural displacements with years of age. RESULTS: Two-way ANOVA yielded a significant main effect of age for all 4 sagittal postural variables and gender for all variables except head translation. No age × gender interaction was found. Polynomial trend analyses showed a significant linear association between child age and all four postural variables: anterior head translation (p < 0.001), anterior shoulder translation (p < 0.001), anterior pelvic translation (p < 0.001), anterior knee translation (p < 0.001). Between the ages of 11 and 12 years, for anterior knee translation, T-test post hoc analysis revealed only one significant rough break in the continuity of the age related trend. CONCLUSION: A significant linear trend for increasing sagittal plane postural translations of the head, thorax, pelvis, and knee was found as children age from 4 years to 12 years. These postural translations provide preliminary normative data for the alignment of a child's sagittal plane posture

Knee disorders in primary care: design and patient selection of the HONEUR knee cohort.

BACKGROUND: Knee complaints are a frequent reason for consultation in general practice. These patients constitute a specific population compared to secondary care patients. However, information to base treatment decisions on is generally derived from specialistic settings. Our cohort study is aimed at collecting knowledge about prognosis and prognostic factors of knee complaints presented in a primary care setting. This paper describes the methods used for data collection, and discusses potential selectiveness of patient recruitment. METHODS: This is a descriptive prospective cohort study with one-year follow-up. 40 Dutch GPs recruited consecutive patients with incident knee complaints aged 12 years and above from October 2001 to October 2003. Patients were assessed with questionnaires and standardised physical examinations. Additional measurements of subgroups included MRI for recent knee traumas and device assessed function measurements for non-traumatic patients. After the inclusion period we retrospectively searched the computerized medical files of participating GPs to obtain a sample to determine possible selective recruitment. We assessed differences in proportions of gender, traumatic onset of injury and age groups between participants and non-participants using Odds Ratios (OR) and 95% confidence intervals. RESULTS: We recruited 1068 patients. In a sample of 310 patients visiting the GP, we detected some selective recruitment, indicating an underrepresentation of patients aged 12 to 35 years (OR 1.70; 1.15-2.77), especially among men (OR 2.16; 1.12-4.18). The underrepresentation of patients with traumatic onset of injury was not statistically significant. CONCLUSION: This cohort is unique in its size, setting, and its range of both age and type of knee complaints. We believe the detected selective recruitment is unlikely to introduce significant bias, as the cohort will be divided into subgroups according to age group or traumatic onset of injury for future analyses. However, the underrepresentation of men in the age group of 12 to 35 years of age warrants caution. Based on the available data, we believe our cohort is an acceptable representation of patients with new knee complaints consulting the GP, and we expect no problems with extrapolation of the results to the general Dutch population

The Shoulder Pain and Disability Index demonstrates factor, construct and longitudinal validity

BACKGROUND: The Shoulder Pain and Disability Index (SPADI) is a self-report measure developed to evaluate patients with shoulder pathology. While some validation has been conducted, broader analyses are indicated. This study determined aspects of cross-sectional and longitudinal validity of the SPADI. METHODS: Community volunteers (n = 129) who self-identified as having shoulder pain were enrolled. Patients were examined by a physical therapist using a standardized assessment process to insure that their pain was musculoskeletal in nature. This included examination of pain reported during active and passive shoulder motion as reported on a visual analogue pain scale. Patients completed the SPADI, the Coping Strategies Questionnaire (CSQ) and the Sickness Impact Profile (SIP) at a baseline assessment and again 3 and 6 months later. Factor analysis with varimax rotation was used to assess subscale structure. Expectations regarding convergent and divergent subscales of CSQ and SIP were determined a priori and analysed using Pearson correlations. Constructed hypotheses that patients with a specific diagnosis or on pain medication would demonstrate higher SPADI scores were tested. Correlations between the observed changes recorded across different instruments were used to assess longitudinal validity. RESULTS: The internal consistencies of the SPADI subscales were high (α > 0.92). Factor analysis with varimax rotation indicated that the majority of items fell into 2 factors that represent pain and disability. Two difficult functional items tended to align with pain items. Higher pain and disability was correlated to passive or negative coping strategies, i.e., praying/hoping, catastrophizing on the CSQ. The correlations between subscales of the SPADI and SIP were low with divergent subscales and low to moderate with convergent subscales. Correlations, r > 0.60, were observed between the SPADI and pain reported on a VAS pain scale during active and passive movement. The two constructed validity hypotheses (on diagnosis and use of pain medications) were both supported (p < 0.01). The SPADI demonstrated significant changes over time, but these were poorly correlated to the SIP or CSQ suggesting that these scales measure different parameters. CONCLUSION: The SPADI is a valid measure to assess pain and disability in community-based patients reporting shoulder pain due to musculoskeletal pathology

Comparative effectiveness of manipulation, mobilisation and the Activator instrument in treatment of non-specific neck pain: a systematic review

BACKGROUND: Neck pain is a common problem and different forms of manual therapy are used in its treatment. The purpose of this systematic review was to critically appraise the literature that directly compared manipulation, mobilisation and the Activator instrument for non-specific neck pain. METHODS: Electronic databases (MEDLINE, MANTIS and CINAHL) were searched from their inception to October 2005 for all English language randomised clinical trials that directly compared manipulation, mobilisation and the Activator instrument. Inclusion and exclusion criteria were applied to select the studies and these studies were then evaluated using validated criteria. RESULTS: Five such studies were identified. The methodological quality was mostly poor. Findings from the studies were mixed and no one therapy was shown to be more effective than the others. CONCLUSION: Further high quality research has to be done before a recommendation can be made as to the most effective manual method for non-specific neck pain

The effectiveness and cost-evaluation of manual therapy and physical therapy in patients with sub-acute and chronic non specific neck pain. Rationale and design of a Randomized Controlled Trial (RCT)

Contains fulltext : 88910.pdf (publisher's version ) (Open Access)BACKGROUND: Manual Therapy applied to patients with non specific neck pain has been investigated several times. In the Netherlands, manual therapy as applied according to the Utrecht School of Manual Therapy (MTU) has not been the subject of a randomized controlled trial. MTU differs in diagnoses and treatment from other forms of manual therapy. METHODS/DESIGN: This is a single blind randomized controlled trial in patients with sub-acute and chronic non specific neck pain. Patients with neck complaints existing for two weeks (minimum) till one year (maximum) will participate in the trial. 180 participants will be recruited in thirteen primary health care centres in the Netherlands.The experimental group will be treated with MTU during a six week period. The control group will be treated with physical therapy (standard care, mainly active exercise therapy), also for a period of six weeks.Primary outcomes are Global Perceived Effect (GPE) and functional status (Neck Disability Index (NDI-DV)). Secondary outcomes are neck pain (Numeric Rating Scale (NRS)), Eurocol, costs and quality of life (SF36). DISCUSSION: This paper presents details on the rationale of MTU, design, methods and operational aspects of the trial. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00713843