Matti Pasanen

Prevention of Hip Fracture in Elderly People with Use of a Hip Protector

BACKGROUND Hip fractures are common in frail elderly adults worldwide. We investigated the effect of an anatomically designed external hip protector on the risk of these age-related fractures. METHODS We randomly assigned 1801 ambulatory but frail elderly adults (1409 women and 392 men; mean age, 82 years), in a 1:2 ratio, either to a group that wore a hip protector or to a control group. Fractures of the hip and all other fractures were recorded until the end of the first full month after 62 hip fractures had occurred in the control group. The risk of fracture in the two groups was compared, and in the hip-protector group the risk of fracture was also analyzed according to whether the protector had been in use at the time of a fall. RESULTS During follow-up, 13 subjects in the hip-protector group had a hip fracture, as compared with 67 subjects in the control group. The respective rates of hip fracture were 21.3 and 46.0 per 1000 person-years (relative hazard in the hip-protector group, 0.4; 95 percent confidence interval, 0.2 to 0.8; P=0.008). The risk of pelvic fracture was slightly but not significantly lower in the hip-protector group than in the control group (2 subjects and 12 subjects, respectively, had pelvic fracture) (relative hazard, 0.4; 95 percent confidence interval, 0.1 to 1.8; P > or = 0.05). The risk of other fractures was similar in the two groups. In the hip-protector group, four subjects had a hip fracture (among 1034 falls) while wearing the protector, and nine subjects had a hip fracture (among 370 falls) while not wearing the protector (relative hazard, 0.2; 95 percent confidence interval, 0.05 to 0.5; P=0.002). CONCLUSIONS The risk of hip fracture can be reduced in frail elderly adults by the use of an anatomically designed external hip protector.

Randomised controlled trial of effect of high-impact exercise on selected risk factors for osteoporotic fractures

BACKGROUND Osteoporotic fractures among the elderly are common, and without preventive measures the burden of these fractures on health-care systems will increase further. The purpose of this randomised controlled study was to evaluate, in premenopausal women, the effects of high-impact loading on several determinants osteoporotic fractures. METHODS 98 healthy, sedentary female volunteers aged 35-45 years were randomly assigned to either a training (n = 49) or a control group (n = 49). Progressive high-impact exercises were done three times per week for 18 months. We measured bone mineral density (BMD) in specific axial and lower-limb sites, by dual-energy X-ray absorptiometry, at baseline and after 12 and 18 months. Maximum isometric strength, muscular and cardiovascular performance, and dynamic balance were also assessed. FINDINGS BMD at the femoral neck, a weightbearing site, increased significantly more in the training group (mean 1.6% [95% CI 0.8-2.4]) than in the control group (0.6% [-0.2 to 1.4], p = 0.006). By contrast, at non-weightbearing sites, such as the distal radius, there was no significant difference between the training and control groups (-1.5% [-2.7 to -0.3] vs -0.7% [-1.9 to -0.5], p = 0.60). In the training group there was a significant improvement in vertical jump and predicted oxygen consumption per min at maximum exercise compared with controls. INTERPRETATION High-impact exercises that load bones with a rapidly rising force profile in versatile movements improve skeletal integrity, muscular performance, and dynamic balance in premenopausal women. If done on a regular basis, this type of exercise may help decrease the risk of osteoporotic fractures in later life. Long-term studies are required to show whether these 18-month results can be translated into long-term benefit.

Effect of a vibration exposure on muscular performance and body balance. Randomized cross-over study

This randomized cross‐over study was designed to investigate the effects of a 4‐min vibration bout on muscle performance and body balance in young, healthy subjects. Sixteen volunteers (eight men, eight women, age 24–33 years) underwent both the 4‐min vibration‐ and sham‐interventions in a randomized order on different days. Six performance tests (stability platform, grip strength, isometric extension strength of lower extremities, tandem‐walk, vertical jump and shuttle run) were performed 10 min before (baseline), and 2 and 60 min after the intervention. The effect of vibration on the surface electromyography (EMG) of soleus, gastrocnemius and vastus lateralis muscles was also investigated. The vibration‐loading, based on a tilting platform, induced a transient (significant at the 2‐min test) 2·5% net benefit in the jump height (P=0·019), 3·2% benefit in the isometric extension strength of lower extremities (P=0·020) and 15·7% improvement in the body balance (P=0·049). In the other 2‐min or in the 60‐min tests, there were no statistically significant differences between the vibration‐ and sham‐interventions. Decreased mean power frequency in EMG of all muscles during the vibration indicated evolving muscle fatigue, while the root mean square voltage of EMG signal increased in calf muscles. We have shown in this study that a single bout of whole body vibration transiently improves muscle performance of lower extremities and body balance in young healthy adults.

High-impact exercise and bones of growing girls: a 9-month controlled trial.

Abstract: The maximum amount of bone a person can obtain during the first two decades of life is an important determinant of bone mass in later life, and an increase in peak bone mass has been associated with decreased risk for osteoporotic fractures. It is known that growth of bone and thus development of peak bone mass are strongly controlled by genetic factors, but information on the role of environmental factors, such as exercise and nutrition, (e.g., exercise) on growing bone is limited. We tested a hypothesis that in growing girls the benefit of mechanical loading on bone mineral mass and bone strength is better before rather than after the menarche. Sixty-four girls (25 premenarcheal, 39 postmenarcheal) carried out a supervised 9-month step-aerobic program (two sessions per week), each session complemented with additional jumps. Sixty-two girls (33 premenarcheal, 29 postmenarcheal) served as controls. Bone mineral content (BMC) at the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometry (DXA). In addition, the cortical density (CoD, mg/cm3) and cortical cross-sectional area (CoA, mm2) and the density-weighted polar section modulus (BSI, mm3) of the tibial midshaft were determined by peripheral quantitative tomography (pQCT). In the premenarcheal girls, BMC increased statistically significantly more in the trainees than controls at the lumbar spine (p= 0.012) (8.6% vs 5.3%) and femoral neck (p= 0.014) (9.3% vs 5.3%). In the tibial midshaft, the intergroup differences (CoD, CoA and BSI) were not significant. The postmenarcheal girls showed no significant post-training intergroup differences in any of the bone parameters (BMC increased in the lumbar spine 6.0% vs 4.9%; femoral neck 3.4% vs 3.2%; and trochanter 2.6% vs 3.5%). Although a large proportion of bone mineral increase in the growing girls of this study was attributable to growth itself, this 9-month exercise intervention showed that a clear and large additional bone gain could be obtained in exercising premenarcheal girls, but not in exercising postmenarcheal girls. In other words, exercise seemed more beneficial for additional bone mineral acquisition before menarche (i.e., during the growth spurt) rather than after it.

Effect of four-month vertical whole body vibration on performance and balance

PURPOSE This randomized controlled study was designed to investigate the effects of a 4-month whole body vibration-intervention on muscle performance and body balance in young, healthy, nonathletic adults. METHODS Fifty-six volunteers (21 men and 35 women, aged 19-38 yr) were randomized to either the vibration group or control group. The vibration-intervention consisted of a 4-month whole body vibration training (4 min.d(-1), 3-5 times a week) employed by standing on a vertically vibrating platform. Five performance tests (vertical jump, isometric extension strength of the lower extremities, grip strength, shuttle run, and postural sway on a stability platform) were performed initially and at 2 and 4 months. RESULTS Four-month vibration intervention induced an 8.5% (95% CI, 3.7-13.5%, P=0.001) net improvement in the jump height. Lower-limb extension strength increased after the 2-month vibration-intervention resulting in a 3.7% (95% CI, 0.3-7.2%, P=0.034) net benefit for the vibration. This benefit, however, diminished by the end of the 4-month intervention. In the grip strength, shuttle run, or balance tests, the vibration-intervention showed no effect. CONCLUSION The 4-month whole body vibration-intervention enhanced jumping power in young adults, suggesting neuromuscular adaptation to the vibration stimulus. On the other hand, the vibration-intervention showed no effect on dynamic or static balance of the subjects. Future studies should focus on comparing the performance-enhancing effects of a whole body vibration to those of conventional resistance training and, as a broader objective, on investigating the possible effects of vibration on structure and strength of bones, and perhaps, incidence of falls of elderly people.

Parent- child relationship of physical activity patterns and obesity

OBJECTIVE: To study differences in physical activity between normal-weight and obese children, as well as parent–child associations of obesity and physical activity.DESIGN: Cross-sectional study.SUBJECTS: 129 obese children (67 girls and 62 boys), 142 normal-weight controls (81 boys and 61 girls), and mothers (n=245) and fathers (n=222) of the children.METHODS: Physical activity was assessed by a 3-day physical activity record (children and parents), by a questionnaire (children), and by one question on habitual physical activity (parents). The data were analysed by stepwise linear and logistic regressions. Obesity was assessed from relative weight (children) and BMI (parents).RESULTS: Parent inactivity was a strong and positive predictor of child inactivity (β-coefficients 0.25 and 0.16, P<0.001, for mother and father inactivity, respectively). Scores of parent activity were somewhat weaker predictors of child vigorous activity hours and total physical activity level (β-coefficients 0.13–0.25, P=0.003–0.08). Child obesity was negatively associated with child habitual physical activity (odds ratio 0.88, P<0.001). In addition, parent obesity (body mass index ≥30 kg/m2) was another strong predictor of child obesity (odds ratio 2.38–3.50, P<0.002).CONCLUSIONS: The present study underscores the parents’ role in childhood activity patterns and obesity. A novel finding was that the parent–child relationship of inactivity appeared to be stronger than that of vigorous activity. Hence, parents who want to reduce their children’s inactivity may have to pay attention to their own lifestyle.

Effect of 8‐Month Vertical Whole Body Vibration on Bone, Muscle Performance, and Body Balance: A Randomized Controlled Study

Recent animal studies have given evidence that vibration loading may be an efficient and safe way to improve mass and mechanical competence of bone, thus providing great potential for preventing and treating osteoporosis. Randomized controlled trials on the safety and efficacy of the vibration on human skeleton are, however, lacking. This randomized controlled intervention trial was designed to assess the effects of an 8‐month whole body vibration intervention on bone, muscular performance, and body balance in young and healthy adults. Fifty‐six volunteers (21 men and 35 women; age, 19‐38 years) were randomly assigned to the vibration group or control group. The vibration intervention consisted of an 8‐month whole body vibration (4 min/day, 3‐5 times per week). During the 4‐minute vibration program, the platform oscillated in an ascending order from 25 to 45 Hz, corresponding to estimated maximum vertical accelerations from 2g to 8g. Mass, structure, and estimated strength of bone at the distal tibia and tibial shaft were assessed by peripheral quantitative computed tomography (pQCT) at baseline and at 8 months. Bone mineral content was measured at the lumbar spine, femoral neck, trochanter, calcaneus, and distal radius using DXA at baseline and after the 8‐month intervention. Serum markers of bone turnover were determined at baseline and 3, 6, and 8 months. Five performance tests (vertical jump, isometric extension strength of the lower extremities, grip strength, shuttle run, and postural sway) were performed at baseline and after the 8‐month intervention. The 8‐month vibration intervention succeeded well and was safe to perform but had no effect on mass, structure, or estimated strength of bone at any skeletal site. Serum markers of bone turnover did not change during the vibration intervention. However, at 8 months, a 7.8% net benefit in the vertical jump height was observed in the vibration group (95% CI, 2.8‐13.1%; p = 0.003). On the other performance and balance tests, the vibration intervention had no effect. In conclusion, the studied whole body vibration program had no effect on bones of young, healthy adults, but instead, increased vertical jump height. Future human studies are needed before clinical recommendations for vibration exercise.

Effects of Unilateral Strength Training and Detraining on Bone Mineral Density and Content in Young Women: A Study of Mechanical Loading and Deloading on Human Bones

This study assessed the effect of unilateral strength training at 80% one repetition maximum and of detraining on bone mineral density (BMD, g/cm-2) and bone mineral content (ΣBMC, g) in young women. Twelve female physiotherapy students trained their left limb by leg press an average of four times per week for 1 year followed by 3 months of detraining. Twelve students served as controls. Repeated bone measurements were performed by dual energy X-ray absorptiometry of the lumbar spine, femoral neck, distal femur, patella, proximal tibia, and calcaneus. The training increased the muscle strength of the trained limb, and the BMD of the same limb showed a nonsignificant but systematic increase in distal femur, patella, and proximal tibia, and in ΣBMC of the five measured limb sites (considered an index of the total osteogenic effectiveness of the training). Simultaneously, the muscle strength increased in the untrained limb as an evidence of cross-training effect. A corresponding small but systematic increase was also seen in BMD of this limb as well as in ΣBMC. After the cessation of training, leg extension strength was retained but BMD and ΣBMC of the trained and untrained limbs declined towards baseline values in 3 months. The BMD and ΣBMC values in the control group showed an increasing tendency during the follow-up but the changes were less than 1%. The differences of the changes in BMD and ΣBMC between the left and right limb in the control group, as well as between the same limb in the training and control groups were nonsignificant. The findings of this study indicate that unidirectional strength training, intensive enough to induce substantial strength gain, is not an effective stimulus to increase BMD and BMC in young, physically active women. The unilateral training model turned out to be feasible in these subjects, producing a definite cross-training effect in muscle strength and a trend of similar effect in BMD. Further development of the unilateral training model, and studies to test if training produces adaptation in nonloaded bones (i.e., a crosstraining effect), are also warranted.

Preventing excessive weight gain during pregnancy - a controlled trial in primary health care.

Objective:To investigate whether individual counselling on diet and physical activity during pregnancy can have positive effects on diet and leisure time physical activity (LTPA) and prevent excessive gestational weight gain.Design:A controlled trial.Setting:Six maternity clinics in primary health care in Finland. The clinics were selected into three intervention and three control clinics.Subjects:Of the 132 pregnant primiparas, recruited by 15 public health nurses (PHN), 105 completed the study.Interventions:The intervention included individual counselling on diet and LTPA during five routine visits to a PHN until 37 weeks’ gestation; the controls received the standard maternity care.Results:The counselling did not affect the proportion of primiparas exceeding the weight gain recommendations or total LTPA when adjusted for confounders. The adjusted proportion of high-fibre bread of the total weekly amount of bread decreased more in the control group than in the intervention group (difference 11.8%-units, 95% confidence interval (CI) 0.6–23.1, P=0.04). The adjusted intake of vegetables, fruit and berries increased by 0.8 portions/day (95% CI 0.3–1.4, P=0.004) and dietary fibre by 3.6 g/day (95% CI 1.0–6.1, P=0.007) more in the intervention group than in the control group. There were no high birth weight babies (⩾4000 g) in the intervention group, but eight (15%) of them in the control group (P=0.006).Conclusions:The counselling helped pregnant women to maintain the proportion of high-fibre bread and to increase vegetable, fruit and fibre intakes, but was unable to prevent excessive gestational weight gain.

The Injury Mechanisms of Osteoporotic Upper Extremity Fractures Among Older Adults: A Controlled Study of 287 Consecutive Patients and Their 108 Controls

Abstract: The risk factors for falls in older adults are well known but knowledge on the direct injury mechanisms that result in various osteoporotic fractures has been very sparse. The purpose of this study was therefore to clarify the injury mechanisms of osteoporotic upper extremity fractures of older adults and to compare these mechanisms with those of the control fallers, and in this way to obtain reliable insight into the etiology and pathogenesis of upper extremity fractures and thus to enable fracture prevention. One hundred and twelve patients with a fresh fracture of the proximal humerus, 65 patients with an elbow fracture, 110 patients with a wrist fracture and 108 controls (no fracture, or a fracture other than the case fracture) were interviewed and examined between September 1995 and December 1997. The inclusion criteria of the subjects were that the patient was 50 years of age or older at the time of the accident, and that the fracture/injury had occurred as a result of low-energy trauma (typically a fall from standing height or less) within a week before the interview and examination. In 97% of patients with a proximal humerus or elbow fracture, and in all patients (100%) with a wrist fracture, the fracture was a result of a fall. In the control group this figure was 93%. In a polychotomous logistic regression analysis the intergroup differences in the fall directions (adjusted by gender, age and functional capacity) were statistically highly significant (χ2= 43.6, d.f. = 15, p<0.001). Most of the patients with a proximal humerus fracture or elbow fracture reported that they had fallen “obliquely forward” (43% and 38%) or “to the side” (29% and 26%), whereas in the wrist fracture group the main fall direction was also “obliquely forward” (34%) but the other fall directions (i.e., “forward”, “to the side”, “obliquely backward” and “backward”) were quite equally represented (13–19%). The odds ratio (OR) for an obliquely forward fall resulting in a proximal humerus fracture was 3.5 [95% confidence interval (CI) 1.4–9.2), as compared with the fall directions of the controls and the “obliquely backward” fall direction. In a logistic regression analysis the patients with a wrist fracture managed to break their fall (e.g., with an outstretched arm) more frequently than the patients in the other groups (OR 3.9; 95% CI 2.0–7.3). The patients with a proximal humerus fracture, in turn, managed to break their fall less frequently than the controls (OR 0.33; 95% CI 0.14–0.80). The same was true of the patients with an elbow fracture, although the difference was not significant (OR 0.49%; 95% CI 0.19–1.3). As objective evidence for a direct fall-induced impact on the fracture site, 68% of patients with a proximal humerus fracture revealed a fresh subcutaneous hematoma on the shoulder/upper arm, while such a hematoma was rare in the controls (2%) (p<0.001). Correspondingly, 62% of patients with an elbow fracture showed a similar hematoma on the elbow area, while this was seen in none of the controls (p<0.001). In patients with a wrist fracture a hand/wrist hematoma was seen in 58% of the victims, as compared with 18% of the controls (p<0.001). The study shows that the most typical osteoporotic upper extremity fractures of older adults have their specific injury mechanisms. A great majority of these fractures occur as a result of a fall and a subsequent direct impact of the fractured site. Effective fracture prevention could be achieved by minimizing the obvious risk factors of falling and reducing the fall-induced impact force with injury site protection.