Changes in kinematics and work physiology during progressive lifting in healthy adults

Purpose: To analyze progression of changes in kinematics and work physiology during progressive lifting in healthy adults. Methods: Healthy participants were recruited. A standardized lifting test from the WorkWell Functional Capacity Evaluation (FCE) was administered, with five progressive lifting low series of five repetitions. The criteria of the WorkWell observation protocol were studied: changes in muscle use (EMG), heart rate (heart rate monitor), base of support, posture and movement pattern (motion capture system). Repeated measures ANOVA's were used to analyze changes during progressive workloads. Results: 18 healthy young adults participated (8 men, 10 women; mean age 22 years). Mean maximum weight lifted was 66 (+/- 3.2) and 44 (+/- 7.4) kg for men and women, respectively. With progressive loads, statistically significant (p < 0.01) differences were observed: increase in secondary muscle use at moderate lifting, increase of heart rate, increase of base of support and movement pattern changes were observed; differences in posture were not significant. Conclusions: Changes in 4 out of 5 kinematic and work physiology parameters were objectively quantified using lab technology during progressive lifting in healthy adults. These changes appear in line with existing observation criteria

Influence of respiration frequency on heart rate variability parameters:A randomized cross-sectional study

BACKGROUND: Many patients visiting physiotherapists for musculoskeletal disorders face psychosocial challenges which may form a large barrier to recover. There are only a limited number of evidence based psychosocial therapies, but they are mainly based on breathing exercises. OBJECTIVE: to study which respiration frequency would lead to the highest relaxation, reflected in vagal tone derived from the heart rate variability (HRV) in healthy subjects. METHODS: A randomized controlled cross sectional study was performed. Respiration cycles of four, five, six, seven and eight breaths per minute (BPM) were delivered in randomized order for two minutes each. HRV metrics were measured during the sessions with electrocardiogram (ECG). Repeated Measures ANOVA's were performed to analyze differences between breathing frequencies. RESULTS: 100 healthy volunteers were included (40 male). Standard Deviation of inter beat intervals (SDNN) values were significantly highest at 5 BPM, whereas the Root Mean Square of Successive Differences (RMSSD) values appeared highest at 7 breaths per minute (p < 0.01). High Frequency (HF) power was lowest at 4 BPM, whereas Low Frequency (LF) power was not significantly influenced by respiration frequency. CONCLUSIONS: Breathing at a frequency of 5 to 7 breaths per minute leads to highest HRV values, but there is no single respiration ratio that maximizes all metrics. Physiotherapists may use five to seven BPM as guidance to determine ideal breathing frequencies

Self-Reported Functional Status as Predictor of Observed Functional Capacity in Subjects with Early Osteoarthritis of the Hip and Knee: A Diagnostic Study in the CHECK Cohort

Objectives Patients with hip or knee osteoarthritis (OA) may experience functional limitations in work settings. In the Cohort Hip and Cohort Knee study (CHECK) physical function was both self-reported and measured performance-based, using Functional Capacity Evaluation (FCE). Relations between self-reported scores on SF-36 and WOMAC (Western Ontario and McMaster Arthritis Index, function scales) and FCE performance were studied, and their diagnostic value for clinicians in predicting observed physical work limitations was assessed. Methods Ninety-two subjects scored physical function on SF-36 (scale 0–100, 100 indicating the best health level) and WOMAC (scale 0–68, 68 indicates maximum restriction) and performed the FCE. Correlations were calculated between all scores. Cross-tables were constructed using both questionnaires as diagnostic tests to identify work limitations. Subjects lifting <22.5 kg on the FCE-test ‘lifting-low’ were labeled as having physical work limitations. Diagnostic aspects at different cut-off scores for both questionnaires were analysed. Results Statistically significant correlations (Spearman’s ρ 0.34–0.49) were found between questionnaire scores and lifting and carrying tests. Results of a diagnostic cross-table with cut-off point <60 on SF-36 ‘physical functioning’ were: sensitivity 0.34, specificity 0.97 and positive predictive value (PV+) 0.95. Cut-off point ≥21 on WOMAC ‘function’ resulted in sensitivity 0.51, specificity 0.88 and PV+ 0.88. Conclusion Low self-reported function scores on SF-36 and WOMAC diagnosed subjects with limitations on the FCE. However, high scores did not guarantee performance without physical work limitations. These results are specific to the tested persons with early OA, in populations with a different prevalence of limitations, different diagnostic values will be found. FCE may be indicated to help clinicians to assess actual work capacity

Scale Inhibitor and Dispersant Based on Poly(Acrylic Acid) Obtained by Redox‐Initiated Polymerization

Low molar mass poly(acrylic acid) (PAA) is generally obtained by free radical polymerization of acrylic acid (AA) in aqueous solution, using thermal initiators and some chain transfer agent. However, under such conditions it is rather difficult to efficiently produce molar masses as low as those required for obtaining an effective dispersant. In this work, the semibatch polymerization of AA at 45 °C is considered, using potassium persulfate (KPS) and sodium metabisulfite (KPS/NaMBS), or alternatively KPS and sodium hypophosphite (KPS/NaHP) as redox initiators to produce PAA of controlled low molar masses. These initiation systems allow the production of PAA with M n as low as 2.0 kDa, relatively narrow molar mass distribution (1.5 95%); and it is verified that both reductants, NaMBS and NaHP, also behave as chain transfer agents. Finally, the investigated process with redox couples allowed the production of PAA with acceptable dispersant and antiscaling properties.Fil: Gutierrez, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Cáceres Montenegro, Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Vega, Jorge Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Work participation and health status in early osteoarthritis of hip and/or knee: a comparison between Cohort Hip and Cohort Knee (CHECK) and Osteoarthritis Initiative (OAI)

OBJECTIVE: Aims of this study were to examine the work participation of Dutch people with early osteoarthritis (OA) in hips or knees, and to compare this with data from the American Osteoarthritis Initiative (OAI) cohort. Additionally, the influence of health status and personal factors on work participation was analysed. METHODS: In the Cohort Hip and Cohort Knee (CHECK study) 1002 subjects were included. Baseline questionnaire data from 970 subjects were analysed. Rate ratios were calculated to compare work participation with the general Dutch population, after correcting (by stratifying) for age, sex and education. Health status was measured using SF-36 and Womac. Groups were compared (CHECK versus OAI, workers versus non-workers) using t-tests. RESULTS: Subjects' mean age was 56 years, 79% were females. Overall participation was 51%, similar to the general Dutch population and lower than in OAI (76%). Point prevalence of sick leave because of hip/knee complaints was 2%, year prevalence 12%. Fourteen percent of the subjects had made work adaptations. Workers reported significantly better health status (corrected for age, sex and education) than non-workers. CONCLUSION: The work participation of Dutch people with early OA is similar to the general population and significantly lower than in American subjects. Increasing age, female sex and lower education level were related to lower participation. Societal factors appear to have more effect on work participation than health status in this stage of OA. Better health status of workers could not be explained solely by selection bias, but may also be a result of work