Environmental barriers perceived by the Finnish population with spinal cord injury: a cross-sectional survey

STUDY DESIGN

Cross-sectional survey of the Finnish population with spinal cord injury (SCI).

OBJECTIVES

To explore the frequencies of perceived environmental barriers (EB) that made participation harder for the Finnish population with SCI and to compare the occurrence of perceived EBs by gender, age, time since injury, and injury severity.

SETTING

Participants were recruited from the registers of the three SCI outpatient clinics responsible for the lifelong care of people with SCI in Finland.

METHODS

The self-administered Nottwil Environmental Factors Inventory Short Form (NEFI-SF) collected in the Finnish Spinal Cord Injury Study (FinSCI) (n = 1772) was used. Nonparametric tests and multinomial logistic regression models were utilized.

RESULTS

880 individuals responded to the NEFI-SF items (response rate 50%). Climate was perceived as a barrier by 72% and a serious one by 44% of the respondents. The rates regarding public access were 59% and 24%, private home access 46% and 18%, and long-distance transport 45% and 20%. Four out of ten respondents reported that finances, lack of assistive devices for short-distance transport, and political decisions restricted their participation. The NEFI-SF total scores were higher (meaning more perceived restrictions by EBs) for those more severely injured.

CONCLUSIONS

Climate, access to public and private places, challenges with transport, finances, and political decisions were the EBs most frequently perceived to restrict participation by the Finnish population with SCI. Most EBs that were prominent causes of restrictions are modifiable. Greater accessibility to the built environment, equal services to all, and positive special treatment could reduce their effects.

The McKenzie Method versus guideline-based advice in the treatment of sciatica: 24-month outcomes of a randomised clinical trial

OBJECTIVE

To compare the effectiveness of a McKenzie Method intervention in patients with sciatica with guideline-based patient education.

DESIGN

Multi-centre, assessor-blinded, parallel-group, randomised trial.

SETTING

Two tertiary hospitals providing operative spinal care.

SUBJECTS

Sciatica patients with magnetic resonance imaging-confirmed lumbar disc herniation compressing a nerve root.

INTERVENTIONS

The McKenzie group received specific back exercises for seven visits combined with an educational book, and the Control group received a single session of self-management guidance according to usual practices.

MAIN MEASURES

The primary outcome was the number of surgical operations. Secondary outcomes were pain measured using the Visual Analogue Scale, disability using the Oswestry Disability Index and health-related quality of life using a RAND-36 questionnaire at baseline and 24-month follow-up.

RESULTS

Altogether 66 patients, mean age of 43 years, of which 50% were females with long-lasting sciatica, mean 16 weeks, were randomised to two groups. Nineteen patients (29%) had surgery. There was no significant difference in surgery rates between the groups. Back and leg pain decreased, and disability improved in both groups. Health-related quality of life improved in six dimensions out of eight in both groups. There were no significant between-group changes in the patient-reported outcomes at the follow-up.

CONCLUSIONS

Multiple sessions of McKenzie-based back exercises with a McKenzie-specific patient's educational book produced effects equal to guideline-based advice at long-term follow-up. However, the power of these results is diminished due to the small patient population and confounding factors.

An international survey of the structure and process of care for traumatic spinal cord injury in acute and rehabilitation facilities: lessons learned from a pilot study

BACKGROUND

To describe the key findings and lessons learned from an international pilot study that surveyed spinal cord injury programs in acute and rehabilitation facilities to understand the status of spinal cord injury care.

METHODS

An online survey with two questionnaires, a 74-item for acute care and a 51-item for rehabilitation, was used. A subset of survey items relevant to the themes of specialized care, timeliness, patient-centeredness, and evidence-based care were operationalized as structure or process indicators. Percentages of facilities reporting the structure or process to be present, and percentages of indicators met by each facility were calculated and reported separately for facilities from high-income countries (HIC) and from low and middle-income countries (LMIC) to identify "hard to meet" indicators defined as those met by less than two-thirds of facilities and to describe performance level.

RESULTS

A total of 26 acute and 26 rehabilitation facilities from 25 countries participated in the study. The comparison of the facilities based on the country income level revealed three general observations: 1) some indicators were met equally well by both HIC and LMIC, such as 24-hour access to CT scanners in acute care and out-patient services at rehabilitation facilities; 2) some indicators were hard to meet for LMIC but not for HIC, such as having a multidisciplinary team for both acute and rehabilitation settings; and 3) some indicators were hard to meet by both HIC and LMIC, including having peer counselling programs. Variability was also observed for the same indicator between acute and rehabilitation facilities, and a wide range in the total number of indicators met among HIC facilities (acute 59-100%; rehabilitation 36-100%) and among LMIC facilities (acute: 41-82%; rehabilitation: 36-93%) was reported.

CONCLUSIONS

Results from this international pilot study found that the participating acute and rehabilitation facilities on average adhered to 74% of the selected indicators, suggesting that the structure and processes to provide ideal traumatic spinal cord injury care were broadly available. Recruiting a representative sample of SCI facilities and incorporating regional attributes in future surveys will be helpful to examine factors affecting adherence to indicators.

Physical health among the Finnish spinal cord injury population according to the Patient Reported Outcome Measurement Information System (PROMIS®)

OBJECTIVE

The aim of this study is to assess the physical health in the Finnish Spinal cord injury (SCI) population using the Patient Reported Outcome Measurement Information System (PROMIS®) and make a comparison to the general United States (US) population. Furthermore, the aim is to explore the associations between pain interference, pain intensity, sleep disturbance, and fatigue and physical function.

DESIGN

Cross-sectional study. This study is part of the Finnish Spinal Cord Injury (FinSCI) community survey study.

SETTING

Community, Finland.

PARTICIPANTS

884 persons with SCI.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

Physical health was measured with custom Patient Reported Outcome Measure System (PROMIS®) short forms.

RESULTS

Higher age and lesion level indicated more severe physical function impairments. Persons ≥46 years exhibited more pain interference symptoms compared to younger participants. On average, the Finnish SCI population had 1.3 SD lower physical function and 0.9 SD higher pain interference T-scores compared to the US general population (P < 0.001). The most significant association was observed between pain interference and physical function (r = -0.364, P < 0.001).

CONCLUSIONS

The present study provides a description of the state of physical health in the Finnish spinal cord injury population, as well as the associations between the physical health areas. The results highlight the substantiality of pain management in terms of improving physical function.

TRIAL REGISTRATION NUMBER

NCT04649814.

Health-related factors for work participation of persons with Spinal Cord Injury in Finland

OBJECTIVE

To explore work participation and the health-related factors affecting work participation among the Finnish Spinal Cord injury (FinSCI) study population (n = 884).

METHODS

A cross-sectional explorative observational study in the FinSCI community survey applying Patient-Reported Outcomes Measurement Information System (PROMIS®) forms on Social Health and Global Health. Analyses of socio-demographic and injury-related data were performed.

RESULTS

Employment among the study population (n = 452) was 26.5%. Physical, Mental, Social and General Health were better in the employed group compared with work-age persons not working. Logistic regression showed that work participation was related to all health domains, but Physical Health and Ability to Participate in Social Roles and Activities in Social Health were the strongest indicators of likelihood of being at work. Paraplegia and young age were associated with increased likelihood of work participation.  Conclusion: The first national survey among people with spinal cord injury in Finland shows low level of employment. The results suggest that pain, physical function, and ability to participate in social roles should be monitored by health and vocational professionals when assessing a person's likelihood of being in work.

Prevalence of comorbidities and secondary health conditions among the Finnish population with spinal cord injury

Study design

A cross-sectional study.

Objectives

To explore the prevalence of comorbidities, secondary health conditions (SHCs), and multimorbidity in the Finnish population with spinal cord injury (SCI).

Setting

The data were collected from the Finnish Spinal Cord Injury Study (FinSCI). Participants were identified from three SCI outpatient clinics responsible for the lifelong follow-up of persons with SCI in Finland, (n = 884 participants, response rate; 50%).

Methods

The FinSCI-questionnaire included a question from the National Study of Health, Well-being, and Service (FinSote) for screening 12 comorbidities. The reference data of the general population for that question were received from the Finnish Institute for Health and Welfare. The Spinal Cord Injury Secondary Condition Scale (SCI-SCS) was used to screen 16 SHCs. The data were analysed with univariate testing and multivariable negative binomial regression modelling.

Results

The most common comorbidities were high blood pressure/hypertension (38%), back problems (28%), and high cholesterol (22%). The most common SHCs were joint and muscle pain (81%), muscle spasms (74%), chronic pain (71%), and bowel problems (71%). The prevalence of comorbidities was highest among persons aged ≥76 years (mean; 2.0; scale range; 0–12). The prevalence of SHCs was highest in the severity of SCI group C1–4 AIS A, B, and C (mean; 8.9; scale range; 0–16).

Conclusions

Further research on geriatrics in SCI, non-traumatic SCI, and knowledge of the needs of persons with cervical lesion AIS A, B, or C is required, due to the fact that the prevalence of multimorbidity is high in these groups.

Epidemiology of traumatic spinal cord injury in Finland

Study design

Prospective cohort study.

Objectives

To determine the incidence and evaluate the characteristics of newly injured patients admitted to two spinal cord injury (SCI) centers during a 4-year period.

Setting

Oulu and Tampere University Hospital, Finland.

Methods

A dedicated multidisciplinary team evaluated all of the patients with new traumatic SCI (TSCI). The data were recorded according to the International Spinal Cord Injury Core Data Sets.

Results

In a 4-year period, 346 new patients with TSCI were admitted to the study centers. In the Oulu and Tampere University Hospitals’ catchment areas, the mean annual incidence of TSCI was 36.6 per million. The leading causes of injury were low-level falls (36.2%), high-level falls (25.5%), and transport-related accidents (19.2%). In the patients >60 years, 72.6% were injured by falling and the proportion of low-level falls was 49.7%. In the patients ≤60 years old, 47.4% were alcohol-related. The proportion of cervical injuries in the patients >60 years was 77.1%, while in the patients ≤60 years the proportion was 59.6%. The incidence of TSCI was higher during the Summer and Autumn months.

Conclusion

The mean annual incidence of TSCI was 36.6 per million corresponding to 200 new annual cases in Finland. Incomplete tetraplegia due to falling among elderly was overrepresented in the study population. Alcohol-consumption preceded injury in nearly half of the cases in the younger population. The prevention should focus on alcohol-related injuries and falls in the elderly.

Home invasive mechanical ventilation in Finland in 2015-2019

INTRODUCTION

The prevalence of long-term invasive mechanical ventilation via tracheostomy in chronic respiratory insufficiency is largely unknown. We aimed to clarify prevalence and aetiology of the use of home invasive mechanical ventilation (HIMV) in Finland in 2015-2019.

METHODS

Information on HIMV patients was collected yearly from all Finnish Hospital District patient registries between 1 January 2015 and 1 January 2019. Data included underlying diagnosis, time from diagnosis to HIMV initiation, treatment length, mortality and basic sociodemographic data.

RESULTS

In 2015, we had 107 HIMV patients. During the follow-up we received 34 new patients (24.1%) and 46 patients (32.6%) died. In 2019, we had 95 HIMV patients and the prevalence in Finland was 2.0 in 100 000. The most common diagnoses were motor neurone disease (29.1%) and spinal cord injuries (19.9%). Mean duration of HIMV among all patients on 1 January 2019 was 12.3 years and among deceased patients, 11.2 years. Treatment durations ranged from 7.7 years for motor neurone disease patients to 47.3 years for post-polio syndrome patients. Most patients (81.6%) used HIMV 24 h·day-1.

CONCLUSIONS

HIMV is a rare, long-lasting treatment, most often used in chronic hypoventilation caused by chronic neurological disease. Based on our 4 year follow-up the prevalence of HIMV seems to be diminishing in Finland. Treatment duration and survival vary greatly depending on the underlying diagnosis. Most of the patients were totally dependent on HIMV, requiring 24-h care.

Incidence of Acquired Nontraumatic Spinal Cord Injury in Finland: A 4-Year Prospective Multicenter Study

OBJECTIVES

To evaluate the incidence and epidemiologic characteristics of acquired nontraumatic spinal cord injury (NTSCI) in Finland.

DESIGN

Prospective 4-year epidemiologic multicenter study.

SETTING

Two of the 3 spinal cord injury (SCI) centers in Finland responsible for acute care, immediate rehabilitation, and lifelong follow-up for all SCI patients in a population of 3,073,052 (as of 2013).

PARTICIPANTS

All newly diagnosed NTSCI patients (N=430) admitted to Tampere University Hospital between 2012 and 2015 and Oulu University Hospital between 2013 and 2016 based on the evaluation of the designated rehabilitation teams. Patients with NTSCI resulting from congenital etiologies or progressive neurologic diseases were excluded.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Incidence and variables, according to the International SCI Core Data Set and the International Standards for Neurological Classification of SCI, including etiology and the severity of injury.

RESULTS

The incidence of NTSCI was 54.1 per million per year. NTSCI was more common in men (n=260, 60.5%) than women (n=170, 39.5%). The mean age was 62.0±14.6 years old. Degenerative causes were the most common etiology (n=219, 50.9%), followed by malignant (n=88, 20.5%) and benign (n=41, 9.5%) neoplasms. The injury resulted in tetraplegia in 177 patients (41.1%) and paraplegia in 249 patients (57.9%). American Spinal Injury Association Impairment Scale grade D injuries were common, with an incidence of 71% (n=304). Specialized inpatient rehabilitation was needed in 44% (n=189) of the cases.

CONCLUSIONS

There are no previous studies on the epidemiology of NTSCI in Finland, and international reporting has been limited. The incidence of NTSCI in our study was substantially higher than in most previous studies, which was likely owing to our study including individuals with less severe lesions who did not require inpatient rehabilitation.

Vibroacoustic treatment to improve functioning and ability to work: a multidisciplinary approach to chronic pain rehabilitation

PURPOSE

To study the use of Vibroacoustic treatment and an added self-care intervention for improving the functioning and ability to work of patients with chronic pain and potential comorbid depressive and anxious symptoms.

MATERIALS AND METHODS

A mixed methods study with four single cases. Participants received bi-weekly Vibroacoustic practitioner-led treatment sessions for five weeks, followed by a one-month washout period without treatments. Then, participants conducted four self-care vibroacoustic sessions per week for five weeks, followed by another month-long washout period. Participants kept diaries of their experiences during this time. Quantitative scales included the World Health Organization Disability Assessment Schedule 2.0, Visual Analogue Scales (pain, mood, relaxation, anxiety, and ability to work), Beck's Depression Inventory-II, and Hospital Anxiety and Depression Scale (Anxiety only). The use of physiological markers was also explored.

RESULTS

The greatest improvement was from the practitioner-led sessions, but self-care was beneficial for pain relief and relaxation. Participants became more aware of sensations in their own bodies, and during washout periods noticed more clearly the treatment effects when symptoms returned. An added self-care phase to standard Vibroacoustic treatment could be beneficial for maintaining the effects from the more intensive Vibroacoustic treatment as part of multidisciplinary rehabilitation.Implications for rehabilitationChronic pain and comorbid mood disorders negatively impact functioning and ability to work.Vibroacoustic treatment with a self-care phase could be beneficial for managing the symptoms of chronic pain if implemented within a naturalistic multidisciplinary rehabilitation context.In four single cases, this study shows functioning, pain, and depression improved after Vibroacoustic treatment with self-care.

Health, functioning and accessibility among spinal cord injury population in Finland: Protocol for the FinSCI study

BACKGROUND AND PURPOSE

The purpose of the Finnish Spinal Cord Injury Study (FinSCI) is to identify factors related to the health and functioning of people with spinal cord injury, their challenges with accessibility, and how such factors are interconnected. The International Classification of Functioning, Disability and Health (ICF) is used as a structured framework in the study.

DESIGN

Protocol of mixed methods study.

RESULTS

Study participants were recruited from all 3 SCI outpatient clinics in Finland. The final target group consists of 1,789 subjects with spinal cord injury. The final questionnaire was formed from 5 different patient-reported instruments. The spinal cord injury-specified instruments are the Spinal Cord Injury Secondary Condition Scale, the Spinal Cord Independence Measure, and the Nottwil Environmental Factors Inventory Short Form. In addition, questions from the following generic instruments were chosen after a selection process: the Patient-Reported Outcomes Measurement Information System, PROMIS®, and the National Study of Health, Well-being and Service, FinSote. Altogether, the final questionnaire covers 64 ICF categories and consists of 151 ICF-linked questions.

CONCLUSION

The formulated questionnaire covers widely different aspects of health, functioning and accessibility. The questionnaire results and subsequent interviews will help in developing care and rehabilitation policies and services for people with spinal cord injury.

Normal-weight obesity and cardiometabolic risk: A 7-year longitudinal study in girls from prepuberty to early adulthood

OBJECTIVE

To study whether normal-weight obesity in childhood is associated with increased cardiometabolic risk in early adulthood.

METHODS

This study assessed data for 236 girls followed from prepuberty to early adulthood. Growth chart data were obtained from birth to 18 years. Body composition was assessed by dual-energy x-ray absorptiometry and cardiometabolic risk by calculating continuous clustered risk score (at ages 11, 14, and 18). The association of body weight status with cardiometabolic risk from childhood to early adulthood was examined.

RESULTS

Subjects with normal-weight obesity were virtually indistinguishable from their normal-weight lean peers in terms of relative body weight and BMI but had significantly higher fat mass (7.1-7.3 kg) and cardiometabolic risk already in childhood, and this difference persisted into early adulthood (P <  0.001 for all).

CONCLUSIONS

Children and adolescents with normal body weight and high body fat percentage may be at increased risk for cardiometabolic morbidity in adulthood. Body fatness may be of utility in clinical practice to effectively identify children and adolescents at risk and to permit recommendation of lifestyle changes that could translate to lower risks of cardiovascular diseases in the future.

Prevalence of life-supporting prolonged invasive ventilation support in Finland

BACKGROUND

There is no comprehensive data in our country on the prevalence of life-supporting prolonged invasive ventilation support. The objective of the survey was to clarify in all hospital districts of continental Finland the prevalence of patients who were dependent on invasive ventilation support, and the disease leading to the treatment.

PATIENTS AND METHODS

The KOTIVEHNO 2015 survey was carried out as population-based cross-sectional study by sending a questionnaire to all doctors in charge of prolonged invasive ventilation support. The questionnaires were used to collect data on the patients within care on 1st January, 2017.

RESULTS

The prevalence of life-supporting prolonged invasive ventilation support in Finland among the population aged over 16 years or more was 2/4 patients/100,000 habitants. Altogether 107 patients were within the care. There was variation in the prevalence among the hospital districts. Of the patients, 24% were affected with a motoneuron disease, in 18% the cause was spinal cord injury, 15% suffered from Duchenne's muscular dystrophy, and the rest had some other rare neurological disease.

CONCLUSIONS

Life-supporting prolonged invasive ventilation support is rare in Finland. The treatment is associated with neuromuscular diseases causing respiratory insufficiency, and with spinal cord injuries.

Effect of office-based brief high-impact exercise on bone mineral density in healthy premenopausal women: the Sendai Bone Health Concept Study

Although there is ample evidence supporting the effectiveness of physical activity in the prevention and treatment of osteoporosis, there are no previous studies to examine the effect of office-based brief high-impact exercise (HIE) on bone mineral density (BMD) in healthy premenopausal women. This study evaluated the effects of office-based HIE on BMD in healthy premenopausal Japanese women. Ninety-one healthy premenopausal women were randomized to receive stretching exercise (SE) or HIE (stretching, along with up to 5 × 10 vertical and versatile jumps) for 12 months. The BMD of the lumbar spine and proximal femur was measured using dual-energy X-ray absorptiometry. Several cardiovascular risk factors and leg strength also were assessed. An accelerometer-based recorder was used to measure daily impact loading in four 1-week samples. The progression of the HIE program was ensured by the accelerometer. Thirty-three women (71.7%) in the SE group and 34 (75.6%) in the HIE group completed the study. There was a significant difference in the change in the femoral neck BMD between the groups in favor of the HIE group [0.6% (95% CI: -0.4, 1.7) vs. -1.0% (95% CI: -2.2, 0.2)]. Adiponectin, LDL, HDL, and the leg strength of participants in both the groups improved during the intervention. These finding suggested that office-based brief HIE can be recommended for premenopausal women for preventing bone mineral loss.

Time-course of exercise and its association with 12-month bone changes

Background

Exercise has been shown to have positive effects on bone density and strength. However, knowledge of the time-course of exercise and bone changes is scarce due to lack of methods to quantify and qualify daily physical activity in long-term. The aim was to evaluate the association between exercise intensity at 3, 6 and 12 month intervals and 12-month changes in upper femur areal bone mineral density (aBMD) and mid-femur geometry in healthy premenopausal women.

Methods

Physical activity was continuously assessed with a waist-worn accelerometer in 35 healthy women (35-40 years) participating in progressive high-impact training. To describe exercise intensity, individual average daily numbers of impacts were calculated at five acceleration levels (range 0.3-9.2 g) during time intervals of 0-3, 0-6, and 0-12 months. Proximal femur aBMD was measured with dual x-ray absorptiometry and mid-femur geometry was evaluated with quantitative computed tomography at the baseline and after 12 months. Physical activity data were correlated with yearly changes in bone density and geometry, and adjusted for confounding factors and impacts at later months of the trial using multivariate analysis.

Results

Femoral neck aBMD changes were significantly correlated with 6 and 12 months' impact activity at high intensity levels (> 3.9 g, r being up to 0.42). Trochanteric aBMD changes were associated even with first three months of exercise exceeding 1.1 g (r = 0.39-0.59, p < 0.05). Similarly, mid-femoral cortical bone geometry changes were related to even first three months' activity (r = 0.38-0.52, p < 0.05). In multivariate analysis, 0-3 months' activity did not correlate with bone change at any site after adjusting for impacts at later months. Instead, 0-6 months' impacts were significant correlates of 12-month changes in femoral neck and trochanter aBMD, mid-femur bone circumference and cortical bone attenuation even after adjustment. No significant correlations were found at the proximal or distal tibia.

Conclusion

The number of high acceleration impacts during 6 months of training was positively associated with 12-month bone changes at the femoral neck, trochanter and mid-femur. These results can be utilized when designing feasible training programs to prevent bone loss in premenopausal women.

Trial registration

Clinical trials.gov NCT00697957

Effect of impact exercise on bone metabolism

SUMMARY

Regular impact exercise in premenopausal women caused positive osteogenic effects associated to low basal serum parathormone (PTH) but had no effects on bone turnover markers PINP or TRACP5b. The low serum basal PTH levels during impact exercise may be a sign of increased incorporation of calcium to bone.

INTRODUCTION

This study aimed to determine the long-term effects of high-impact exercise on bone turnover and calciotropic hormones.

METHODS

We performed a 12-month population-based, randomized, controlled exercise trial in 120 women (age 35-40 years) randomly assigned to an exercise group (EG; n = 60) or a control group (CG; n = 60). The exercise regimen consisted of supervised high-impact exercises three times per week. Daily impact loading was assessed by using an accelerometer. Bone turnover markers and calciotropic hormones were analyzed at 0, 6, and 12 months.

RESULTS

Twelve months of impact exercise did not reveal any treatment effects in bone turnover markers PINP or TRAPC5b, whereas serum basal PTH decreased significantly more in the EG than in the CG (-11.2 vs. -2.2 pg/mL; p = 0.03). The change in PTH was dose dependent and most clearly seen in subjects with 96 to 130 daily impacts at 2.5 to 5.3 g (e.g., running or jumping).

CONCLUSIONS

Regular impact exercise does not cause persistent alterations in bone turnover emphasizing necessity of continuous training to achieve bone benefits. Impact exercise training lowers the serum basal PTH levels and possibly enables greater difference between the basal PTH and transient exercise-induced PTH peaks leading to osteogenic effects.

Effect of impact exercise on physical performance and cardiovascular risk factors

INTRODUCTION

Impact exercise is known to be beneficial for bones, but information regarding its effects on other health aspects is scarce. The aim of this study was to assess the effects of high-impact exercise on physical performance and glucose and lipid profiles.

METHODS

We performed a 12-month, population-based, randomized controlled trial with 120 women (60 in the exercise group and 60 in the control group; ages 35-40 yr). The exercise regimen comprised supervised, progressive, high-impact exercises two to three times per week and an additional home program. Physical activity was continuously recorded using an accelerometer-based method and was analyzed as the daily number of impacts within five acceleration ranges between 0.3 and 9.2g (g = acceleration of gravity: 9.81 m x s(-2)). The changes in physical performance and in glucose and lipid profiles were determined.

RESULTS

Thirty-nine women in the exercise group and 41 women in the control group completed the study. Maximal oxygen uptake (6.2 vs 3.1 mL x kg(-1) x min(-1); P = 0.008) and countermovement (2.3 vs -0.3 cm; P < 0.001) and static (1.4 vs -0.3 cm; P = 0.004) jump heights increased significantly more in the exercise group than in the control group. Exercise training also decreased waist (-1.1 vs 0.9 cm; P = 0.048) and hip circumference (-1.0 vs 1.1 cm; P = 0.037). Total cholesterol and LDL cholesterol decreased significantly more in women, with the highest number of impacts compared with the lowest quartile at intensities exceeding 1.1g, with differences being up to -0.5 mM (P = 0.005). Additionally, poor baseline values predicted greater exercise effects.

CONCLUSION

The moderate-intensity exercise regimen, initially targeted at weight-bearing bones, improved cardiorespiratory fitness, speed-strength, and lipid profiles. In addition to bone health, impact exercise may be recommended for prevention of cardiovascular diseases.

Effect of impact exercise and its intensity on bone geometry at weight-bearing tibia and femur

INTRODUCTION

Physical activity is known to enhance the mechanical competence of bone. However, information about the optimal type of exercise is limited. The aim of this study was to evaluate the contribution of jumping exercise to changes in bone geometry.

METHODS

We carried out a 12-month population-based trial with 120 women (aged 35-40 years), randomly assigned to an exercise group or to a control group. The exercise regimen consisted of supervised, progressive high-impact exercises three times per week and an additional home program. The intensity of impact loading was assessed as the magnitude of acceleration peaks using an accelerometer-based body movement monitor. The activity was analyzed as the daily number of impacts within five acceleration ranges (0.3-1.0g, 1.1-2.4g, 2.5-3.8g, 3.9-5.3g and 5.4-9.2g; g=acceleration of gravity, 9.81 m/s(2)). Bone geometry was assessed with spiral quantitative computed tomography (QCT) scanner at mid-femur, proximal tibia and distal tibia.

RESULTS

Thirty-nine women (65%) in the exercise group and 41 women (68%) in the control group completed the study. QCT and physical activity data were available from 65 subjects. The exercise group showed a significant 0.2% (p=0.033) higher gain in bone circumference compared to the control group at mid-femur. Subgroup analyses revealed geometric changes indicating up to a 2.5% increment in bone strength in favor of the most active exercisers (>66 exercise sessions during the 12 months) compared to the least active exercisers (<19 sessions). In pooled groups, the changes in cortical attenuation and cross-sectional moment of inertia correlated positively (p<0.05-p<0.01) with the number of impacts exceeding 1.1g, while changes in cortical thickness (p<0.05) and bone circumference (p<0.05-p<0.01) were positively associated with impacts 3.9g, or more. The number and intensity of impacts during the 12 months were the most significant predictors of changes in bone geometry explaining up to 36% of changes.

CONCLUSIONS

Bone geometry adapts to impact exercise and the adaptation is most marked at the mid-femur. The changes in bone geometry are associated with the number and intensity of daily impacts while the redistribution of bone mineral appears to be the main mechanism in the skeletal adaptation to varying intensities of exercise.

Acceleration slope of exercise-induced impacts is a determinant of changes in bone density

High acceleration levels (>4g) seen during impact exercises have been shown to increase bone mineral density (BMD) in premenopausal women. The aim of this study was to examine how the other acceleration signal characteristics, i.e. the slope, area and energy of the signal are related to changes in bone density, using long-term quantification of physical activity. Daily physical activity was continuously assessed with a waist-worn accelerometer-based body movement monitor in 64 premenopausal women participating in a 12-month population-based exercise trial. The daily number of exercise-induced impacts at different slope, area and energy levels of the acceleration signal was analyzed. Physical activity inducing slopes 1000 m/s(3), acceleration peak areas 2m/s or signal energies 75 m(2)/s(3) was associated with BMD change in the hip (p<0.05). Impacts with the smallest slopes (<1000 m/s(3)) were positively associated with changes in calcaneal speed of ultrasound, while impacts with slopes 1500 m/s(3) or areas 4m/s were positively correlated with broadband ultrasound attenuation changes (p<0.05). We conclude that the acceleration slope of exercise-induced impacts is an important determinant of bone density. The slope threshold for improving BMD at the hip is 1000 m/s(3), which can be achieved during normal exercise including fast movements such as running and jumping.

Effect of daily physical activity on proximal femur

BACKGROUND

The incidence of osteoporotic fractures is increasing and has become one of the major health problems in developed countries. Physical exercise has been found to be effective in the prevention of osteoporosis. However, the optimal amount of exercise is not known. The aim of this study was to examine the association between the intensity of physical activity and bone mineral density at the proximal femur, using long-term quantification of daily physical activity.

METHODS

The study subjects were 64 women (age 35-40 years), who carried an accelerometer-based body movement recorder for 12 months for individual quantification of their daily physical activity. The average distribution of daily accelerations was defined using 33 acceleration levels.

FINDINGS

A significant relationship between physical activity data and proximal femur bone mineral density was found. Physical activity that induced acceleration levels exceeding 3.6g correlated positively with the bone mineral density change at the proximal femur, the association being strongest at the femoral neck at 5.7 g (r = 0.416, P = 0.001).

INTERPRETATION

The association between physical activity and changes in proximal femur bone mineral density was dependent on the acceleration level of exercise. The quantity and quality of exercise can be monitored with the accelerometer-based physical activity monitor, and the method might be used for optimizing exercise for prevention of osteoporosis.

Intensity of exercise is associated with bone density change in premenopausal women

INTRODUCTION

High-impact exercise is known to be beneficial for bones. However, the optimal amount of exercise is not known. The aim of the present study was to evaluate the association between the intensity of exercise and bone mineral density (BMD).

METHODS

We performed a 12-month population-based trial with 120 women (aged 35-40 years) randomly assigned to an exercise group or to a control group. The intensity of the physical activity of 64 women was assessed with an accelerometer-based body movement monitor. The daily activity was analyzed at five acceleration levels (0.3-1.0 g, 1.1-2.4 g, 2.5-3.8 g, 3.9-5.3 g, and 5.4-9.2 g). BMD was measured at the hip, spine (L1-L4), and radius by dual-energy x-ray absorptiometry. The calcaneus was measured using quantitative ultrasound.

RESULTS

Physical activity that induced acceleration levels exceeding 3.9 g correlated positively with the BMD change in the hip area (p<0.05-0.001). L1 BMD change correlated positively with activity exceeding 5.4 g (p<0.05) and calcaneal speed of sound with the level of 1.1-2.4 g (p< 0.05). Baseline BMD was negatively associated with the BMD change at the hip.

CONCLUSION

The intensity of exercise, measured as the acceleration level of physical activity, was significantly correlated with BMD changes. Bone stimulation is reached during normal physical exercise in healthy premenopausal women. In the hip area, the threshold level for improving BMD is less than 100 accelerations per day at levels exceeding 3.9 g.

Vertical-cavity saturable-absorber intensity modulator

We propose and demonstrate a reflection-type optical modulator, with surface-normal architecture, that exploits the optical saturation of absorption in semiconductor quantum wells. The modulation section of the modulator, which is composed of quantum wells placed within a Fabry-Perot cavity, is optically controlled by an intensity-modulated beam generated by an in-plane laser integrated monolithically on the same wafer and grown in a single epitaxial step. The modulation section and the in-plane laser share the same medium; therefore, efficient coupling between the control beam and the signal beam is achieved. The device was successfully used for active mode locking of an erbium-doped fiber laser.

Self-starting stretched-pulse fiber laser mode locked and stabilized with slow and fast semiconductor saturable absorbers

A self-starting stretched-pulse mode-locked erbium-doped fiber laser that uses fast and slow semiconductor saturable absorbers is described. By using two absorbers, we obtained reliable operation at a fundamental repetition rate with 250 pJ of pulse energy without multiple-pulse breakup. External chirp compensation was used to compress the highly chirped pulses to durations of 135 fs.