AGE–GENDER DIFFERENCE IN THE PERCEPTION AND MUSCLE RESPONSE THRESHOLDS OF SUPPORT SURFACE ROTATION

Proprioception while standing is important for the balance control, but the proprioception has not been investigated in the unconstrained standing conditions. The purpose of this study was to investigate the effects of age and gender on the thresholds of perception and muscle response in response to the support surface rotation. The experiment was designed so that the thresholds depend mainly on the proprioception, i.e., quasistatic condition (0.2∘/s rotation of the platform) with eyes closed. Fifty-two healthy subjects (half young and half elderly) participated in this study. A platform was developed which can be rotated in four directions. Perception threshold angle was registered from subjects’ pressing a button. Muscle response threshold angle was determined as the earlier onset of EMG in lower limb muscles. Two standing conditions (feet together and natural stance) were tested. Repeated-measures ANOVA showed that both thresholds increased with age. Post hoc tests revealed (1) that the perception threshold was greater for women than men in the elderly and (2) both thresholds of the elderly were greater for the feet-together stance than natural stance. Inferior perception sensitivity of platform rotation in elderly women may be associated with inferior performance in cortical postural control and greater fall ratio compared to elderly men, which suggests the need of proprioception trainings.

Fall-induced deaths among older adults: nationwide statistics in Finland between 1971 and 2009 and prediction for the future

BACKGROUND

Fall-related injuries and deaths of elderly people are a major public health concern.

METHODS

Using the Official Cause-of-Death Statistics of Finland we determined the current trends in the number and age-adjusted incidence (per 100,000 persons) of fall-induced deaths among older Finnish men and women by taking into account all persons 50 years of age or older who died because of a fall-induced injury between 1971 and 2009.

RESULTS

Among elderly Finnish men, the number of deaths due to falls increased considerably between the years 1971 and 2009, from 162 to 627 (a 287% increase). The age-adjusted incidence also increased from 43.4 (per 100,000 persons) in 1971 to 57.9 in 2000, but stabilized thereafter (57.3 in 2009). Among elderly Finnish women, the number of fall-induced deaths increased till the beginning of the new millennium (from 279 in 1971 to 499 in 2000) but stabilized thereafter (506 in 2009), and, in sharp contrast to men, women's age-adjusted incidence of fall-induced deaths declined during the entire study period, the incidence being 77.2 in 1971 while only 35.3 in 2009.

CONCLUSIONS

Between 1971 and 2009 the number of fall-induced deaths increased among elderly Finns. The changes were sex-specific so that men surpassed women in both the number and age-adjusted incidence of these fatal falls. Welcome observations were that men's age-adjusted incidence of fall-induced deaths started to stabilize during the new millennium and that in women this incidence continuously declined between 1971 and 2009.

Linked versus unlinked hospital discharge data on hip fractures for estimating incidence and comorbidity profiles

Background

Studies comparing internally linked (person–identifying) and unlinked (episodes of care) hospital discharge data (HDD) on hip fractures have mainly focused on incidence overestimation by unlinked HDD, but little is known about the impact of overestimation on patient profiles such as comorbidity estimates. In view of the continuing use of unlinked HDD in hip fracture research and the desire to apply research results to hip fracture prevention, we concurrently assessed the accuracy of both incidence and comorbidity estimates derived from unlinked HDD compared to those estimated from internally linked HDD.

Methods

We analysed unlinked and internally linked HDD between 01 July 2005 and 30 June 2008, inclusive, from Victoria, Australia to estimate the incidence of hospital admission for fall-related hip fracture in community-dwelling older people aged 65+ years and determine the prevalence of comorbidity in patients. Community-dwelling status was defined as living in private residence, supported residential facilities or special accommodation but not in nursing homes. We defined internally linked HDD as the reference standard and calculated measures of accuracy of fall-related hip fracture incidence by unlinked HDD using standard definitions. The extent to which comorbidity prevalence estimates by unlinked HDD differed from those by the reference standard was assessed in absolute terms.

Results

The sensitivity and specificity of a standard approach for estimating fall-related hip fracture incidence using unlinked HDD (i.e. omitting records of in-hospital deaths, inter-hospital transfers and readmissions within 30 days of discharge) were 94.4% and 97.5%, respectively. The standard approach and its variants underestimated the prevalence of some comorbidities and altered their ranking. The use of more stringent selection criteria led to major improvements in all measures of accuracy as well as overall and specific comorbidity estimates.

Conclusions

This study strongly supports the use of linked rather than unlinked HDD in injury research. In health systems where linked HDD are unavailable, current approaches for identifying incident hip fractures may be enhanced by incorporating additional evidence-based criteria.

Effects of an exercise program on balance and trunk proprioception in older adults with diabetic neuropathies

BACKGROUND

Diabetes is the most common cause of peripheral neuropathies. No definitive treatment for diabetic neuropathies has been reported, and very few studies have been published on the role of exercise in reducing either the symptoms or incidence of diabetic neuropathies.

METHODS

This study assessed the effects of an exercise program on balance and trunk proprioception in older adults with diabetic neuropathies. Thirty-eight patients with diabetes having peripheral neuropathies were enrolled, randomized, and subdivided in two groups: an experimental group of 19 participants with diabetes (72.9 ± 5.6 years old) and a control group of 19 participants with diabetes (73.2 ± 5.4 years old). Both groups received health education on diabetes for 50 min/week for 8 weeks. The experimental group practiced an additional balance exercise program for 60 min, two times a week. The exercise training was performed two times per week for 8 weeks. Results were evaluated by both static and dynamic balance and trunk proprioception.

RESULTS

Postural sway significantly decreased (P < 0.05), the one-leg stance test significantly increased (P < 0.05), and dynamic balance from the Berg Balance Scale, Functional Reach Test, Timed Up and Go test, and 10-m walking time improved significantly after balance exercise (P < 0.05). Trunk repositioning errors also decreased with training (P < 0.05).

CONCLUSION

The balance exercise program improved balance and trunk proprioception. These results suggested that a balance exercise is suitable for individuals with diabetic neuropathy.

Gait Disorders and Falls

Since approximately 30% of persons over the age of 65 fall each year, prevention of falls is a very important topic. Gait disorders and diminished ability to walk safely are associated with an increased risk of falling. In older adults, falls commonly lead to injuries, institutionalization, and early death. The resultant decline in activities of daily living further contributes to loss of mobility and independence. Gait analysis using the dual-task paradigm (e.g., walking and carrying a cup of tea) offers a sensible tool for detecting older persons prone to falling. Changes in gait patterns due to simultaneously performing a secondary attention-demanding task are interpreted as interference by competing demands for attentional resources in gait control. Exercise interventions such as Jaques-Dalcroze eurhythmics address these attentional properties and aim to decrease such interference. To fully stress physical capacities in older adults, not only does automaticity of walking have to be trained, but also simultaneous performance of additional tasks. Exercise interventions for fall prevention should focus on developing basic skeletal muscle strength as a prerequisite to training gait automaticity in dual or multiple task situations. Recommendations for further research center on new approaches to combine exercises with additional tasks to improve gait and functionality in older adults.