Analysis of human locomotion by recording sole-floor reaction forces from anatomically discrete points

Sole-floor reaction forces were recorded from five anatomically discrete points to analyze characteristics of human locomotion. Strain gauge of 14 mm diameter were firmly attached to the sole of bare-foot for recording force changes from the following five points: (1) medial process of calcaneus, (2) head of 1st metatarsal, (3) head of 3rd metatarsal, (4) head of 5th metatarsal and (5) great toe. Fifteen healthy adults were asked to walk at 2, 4, 6 and 8 km/h and to run at 8 km/h on the treadmill. Sole-floor reaction forces from 1st to 5th metatarsals show reciprocal changes during stance phase, while force from 1st metatarsal is strong 5th metatarsal shows weak reaction and vice versa. This phenomenon may be an expression of locomotor program to maintain vertical stability of the body during stance phase. There was a linear relation between walking speeds and sum of force from the five points, although sum of forces from three metatarsals did not change significantly during the walking speeds, indicating mainly calcaneus and great toe contribute to increasing walking speed. During running the sum of force from the three metatarsals increased sharply, joining the other two points to increase thrust.     

Osteogenesis imperfecta in childhood: impairment and disability. A prospective study with 4-year follow-up

OBJECTIVES: To study (1). changes in anthropometrics, joint range of motion (ROM), muscle strength, functional ability, caregiver assistance, and level of ambulation in children with osteogenesis imperfecta (OI) and (2). the prediction of clinical characteristics at the level of ambulation at follow-up and the prediction of clinical characteristics on progression or regression at the level of ambulation over time. DESIGN: Prospective study with follow-up of 4 years. SETTING: A children's hospital that serves a nationwide center for treatment and research in children with OI in the Netherlands. PARTICIPANTS: At follow-up, 49 children (24 boys, 25 girls; mean age +/- standard deviation, 11.3+/-3.8y; range, 5.2-19.4y) participated. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Anthropometry, joint ROM, muscle strength, fracture frequency, intramedullary rodding, level of ambulation, functional ability, and caregiver assistance. RESULTS: In type I OI, total joint ROM decreased significantly over time, especially in the lower extremities, with a significant decrease in generalized joint hypermobility according to Bulbena (median start, 7.5; interquartile range [IQR], 4-9; median end, 6; IQR, 2-7; P<.001). In types III and IV, a severe decrease in total joint ROM was present without significant changes over time. No significant changes in total muscle strength (upper or lower extremities) in the different types of OI were measured at follow-up. In OI type I, a significant increase in self-care (P=.003) and social function (P=.008) was measured; in type III, a significant increase in self-care (P=.003), mobility (P=.004), and social function (P=.005) was measured, with a significant decrease in parental assistance in self-care (P=.02) and mobility (P=.005). In type IV, a significant increase was observed in the self-care (P=.01) and social function domains (P=.02). Type of OI (regression coefficient=-1.0; 95% confidence interval [CI], -1.64 to -0.47) and total muscle strength were the only significant predictors for level of ambulation (regression coefficient=.01; 95% CI,.17-.32). Body weight was significantly lower in the group that progressed in level of ambulation (P=.03), whereas children with a decline in level of ambulation had significantly higher body weight (P=.05). CONCLUSIONS: Ours is the first study with a long-term follow-up that provides information concerning the natural course of developmental outcome parameters of OI in childhood. Joint ROM and muscle strength did not change significantly over time, possibly because of the biomechanical skeletal properties of the different OI types. Functional ability improved significantly over time, but, especially in types III and IV, did not reach normative values, possibly because of a plateau phase in functional ability. Knowledge of the natural course of the disease is essential to interpret the results from intervention studies.     

Walking performance of vestibular-defective patients before and after unilateral vestibular neurotomy

The present study investigated goal-directed linear locomotion in nine Menière’s patients before and after (1 week, 1 and 3 months) a curative unilateral vestibular neurotomy (UVN). Experiments were done using a 3D motion analysis system in subjects walking eyes open (EO) and eyes closed (EC) towards a real or memorized target, respectively. Locomotor pattern (velocity, step length, step frequency and walk ratio) and walking trajectory deviations were evaluated for normal and fast speeds of locomotion and compared to those recorded in 10 healthy subjects. Before UVN, patients showed no walking deviation but gait pattern changes characterized by slower walks compared to the controls, mainly due to step length and step frequency reductions for both visual conditions and locomotion speeds. In the acute stage after UVN, locomotor pattern impairments were significantly accentuated. On the other hand, patients showed strong walking deviations towards the lesioned side with EC. Opposite lateral deviation towards the intact side were observed with EO for normal speed only. Recovery from impaired locomotor pattern was achieved within 1 month for normal speed but remained uncompensated 3 months post-lesion for fast speed particularly in EC condition. Finally, the walking trajectory deviation towards the lesioned side in the dark was maintained up to 3 months after UVN. The results show that central processing of visual and vestibular cues contributes to an accurate locomotor pointing. They argue for an increased weight of visual reference frame on locomotor functions when vestibular function is unilaterally impaired.     

Bone Mineral Density and Lifetime Physical Activity in South African Women

We investigated the relation between lifetime physical activity and bone mineral density (BMD) in South African women using data collected in a case-control study of breast cancer in relation to BMD. Subjects (n = 144) were of black African or mixed ancestral origin, and <60 years of age (mean age 42.6 ± 8.9 years). Cases had newly diagnosed breast cancer (n = 62) and controls were referred for conditions unrelated to BMD or breast cancer (n = 82). Physical activity data consisting of household, occupational and leisure-time activity, and activity for transport, were collected via questionnaire at 4 life stages (epochs), viz. 14–21, 22–34, 35–50, and 50+ years of age. Total energy (MET hrs) and peak strain scores were calculated. Lumbar spine and total proximal femur BMD were measured using dual-energy x-ray absorptiometry. BMD measures were similar between groups, therefore data were combined. BMD measures were unrelated to total lifetime physical activity. However, the major determinants of total proximal femur BMD included age, transport activity including walking and bicycling between the ages of 14 and 21 years, and current weight (adjusted r² = 0.33, P < 0.0001). The major determinants of lumbar spine BMD included age, household energy expenditure between the ages of 14 and 21 years, and current weight (adjusted r² = 0.23, P < 0.0001). Total peak bone strain score for activities between 14–21 years of age was also significantly correlated with lumbar spine BMD (r = 0.18, P < 0.05). Intraclass correlation coefficients to assess tracking of activity through epochs 1, 2, and 3 were high for total energy expenditure (0.96; 95%CI: 0.94–0.97), household (0.98; 95%CI: 0.97–0.99) and occupational activity (0.78; 95%CI: 0.71–0.84) and activity for transport (0.92; 95%CI: 0.89–0.94). These data suggest that walking or activities resulting in impact loading at a young age are associated with higher BMD in later years. In addition, our findings suggest tracking of physical activity over time.     

Active or passive journeys and low back pain in adolescents

The objective of this cross-sectional study was to study associations between low back pain (LBP) and modes of transport to school and leisure activities among adolescents. The study population included all adolescents in eighth and ninth grade in two geographic areas in eastern Norway. Eighty-eight adolescents participated (mean age 14.7 years), making the response rate 84%. Data concerning active (walking/bicycling) and passive (bus/car) journeys were obtained from lists and maps from local authorities, and from the pupils, using a questionnaire that also included LBP, activities and wellbeing. Distance walked/bicycled to school was slightly shorter among those reporting LBP in bivariate analyses. Walking/bicycling more than 8 km weekly to regular activities was inversely associated with LBP in multivariate analysis (OR 0.3; 95% confidence interval 0.1–1.0). No associations were found between passive journeys and LBP. The results raise the question for future research of whether lack of active transport may be one cause behind the increase in juvenile LBP.     

Three by three weeks of robot-enhanced repetitive gait therapy within a global rehabilitation plan improves gross motor development in children with cerebral palsy – a retrospective cohort study

AimTo assess the improvement in gross motor function following three blocks of a three-week, intensive robot-enhanced treadmill therapy (ROBERT-Program).Methodretrospective chart review in a before-after interventional trial in children with cerebral palsy attending a university hospital outpatient rehabilitation centre. Patients received three blocks of a three-week, 12 sessions ROBERT-Program over a mean period of 24 months. Outcome measures were block specific and cumulative improvement in GMFM 66, D and E. Longterm GMFM 66 improvements were compared to the individuals' expected increment as derived from previously published GMFM-66 percentiles. 95% confidence intervals (CI) and paired t-test were calculated.Results20 children (8 GMFCS Level II; 12 GMFCS Level III, mean age 5.9 years (CI: [5.0; 6.7])) were treated. For each block a significant increase in motor performance in similar size could be observed without deterioration between blocks. The cumulative improvement during 21 months observation period was: 6.5 (CI: [4.8; 8.2]) in GMFM 66, which represents a clinically meaningful effect size of 3.6 (CI: [1.4; 5.8]) above the expected improvement.InterpretationProgressive clinically meaningful improvement in motor performance for three blocks of ROBERT-Program was observed. Cumulative GMFM 66 improvements exceeded the individuals' age-specific expected course.     

Normative childhood EMG gait patterns

The population characteristics of the linear envelopes of the electromyograms measured from seven lower extremity muscles in children were studied during locomotion. The variability and changes in pattern with respect to walking speed and age were investigated using statistical properties and analysis of variance of the envelopes. All muscles studied showed changes in their patterns that were associated with different walking speeds. Some changes concerned the relative intensity of existing phases of activity whereas others concerned the existence of additional phases of activity. The most remarkable trend was that all envelopes tended to have more consistent patterns as speed increased. With regard to age, within the span of 4-11 years, only the two thigh muscles studied demonstrated appreciable differences.     

Physical activity and function in older, long-term colorectal cancer survivors

Objective  Increasing age and cancer history are related to impaired physical function. Since physical activity has been shown to ameliorate age-related functional declines, we evaluated the association between physical activity and function in older, long-term colorectal cancer survivors. Methods  In 2006–2007, mailed surveys were sent to colorectal cancer survivors, aged ≥65 years when diagnosed during 1995–2000, and identified through a state cancer registry. Information on physical activity, physical function, and relevant covariates was obtained and matched to registry data. Analysis of covariance and linear regression were used to compare means and trends in physical function across levels of activity in the final analytic sample of 843 cases. Results  A direct, dose-dependent association between physical activity and function was observed (p _trend < .001), with higher SF-36 physical function subscores in those reporting high versus low activity levels (65.0 ± 1.7 vs. 42.7 ± 1.7 (mean ± standard error)). Walking, gardening, housework, and exercise activities were all independently related to better physical function. Moderate–vigorous intensity activity (p _trend < .001) was associated with function, but light activity (p _trend = 0.39) was not. Conclusion  Results from this cross-sectional study indicate significant associations between physical activity and physical function in older, long-term colorectal cancer survivors.     

Poster 5: Short-term effects of locomotor-oriented rehabilitation on postarthroplasty hip impairments and functional ability

Objective: To evaluate the effects of intensive rehabilitation offered 6 months after total hip arthroplasty (THA). Design: Intervention pilot study, before-after trial. Setting: Ambulatory care. Patients: 10 patients were evaluated 7.2±0.5 months after THA (pretest) and 2 months later (posttest). Intervention: 12 supervised sessions and unsupervised home exercises. Main Outcome Measures: Functional ability measured with Western Ontario and McMaster Universities Osteoarthritis Index (pain and disability scales), clinical locomotor tests, and laboratory gait evaluation. Hip strength and mobility impairments were also quantified. Comparisons were made with Wilcoxon signed-rank tests. Results: At posttest, patients had less pain (-56%) and less difficulty in performing daily activities (disability scale, −42%), and they performed better during the 10m walk (15%), 6-minute walk (16%), and timed stair (17%) tests, as compared with pretest. No differences were revealed in gait kinematics and kinetics or impairment measures on the operated limb. Significant changes were found in the movements of the sound limb. Conclusions: The intervention promoted better functional ability. Functional gains seem related to more efficient compensations with the sound limb and better locomotor endurance. These results stress the importance of measuring joint-specific outcomes and using bilateral measures to understand changes in global functional outcomes.