Biomedical subjects

I Melzer

Publications and source records attributed to I Melzer.

4 recordsLinked to original sources

PubMed2004

Postural stability in the elderly: a comparison between fallers and non-fallers.

BACKGROUND: the identification of specific risk factors for falls in community-dwelling elderly persons is required to identify older people at risk of falling. OBJECTIVE: the aim of the study was to determine the ability of various biomechanical measures of postural stability to identify fallers in the elderly population. METHOD: 19 subjects (78.4 +/- 1.3 years old) who reported having fallen unexpectedly at least twice in the last 6 months, and 124 non-fallers (77.8 +/- 0.53 years old) participated in the study. Balance measurements were made in the upright position in six different conditions using a force platform, and the Limits of Stability Test was carried out. Static two-point discrimination (TPD) testing to the underside of the first toe was made to evaluate the innervation density of the slowly adapting receptors. Finally, maximal isometric lower limb strength was measured in major muscle groups. Repeated measures analysis of variance tests were performed to assess the mean differences between the two groups (fallers and non-fallers). The level of significance was set to 0.05. RESULTS AND DISCUSSION: results suggest that control of balance in narrow base stance may be an important tool in identifying elderly fallers. The findings show an increase in mediolateral sway in narrow base stance in older people who experienced recurrent falls. Also, TPD appears to be impaired in elderly fallers (14.93 +/- 1.1 mm versus 12.98 +/- 0.3 mm). CONCLUSIONS: simple and safe laboratory quantitative tests were able to differentiate between elderly fallers and elderly individuals who did not fall, suggesting a possible clinical application as a preliminary screening tool for predicting future risk of falling.

Accidental Falls↗

PubMed2001

Comparative study of osteoarthritis of the contralateral knee joint of male amputees who do and do not play volleyball.

OBJECTIVE: To assess the prevalence of osteoarthritis (OA) of the contralateral knee of men with traumatic amputation who do and do not participate in regular, vigorous physical activity. METHODS: Three groups of patients were assessed. Group 1 consisted of 8 male amputee volleyball players. Group 2 consisted of 24 male amputees who do not play volleyball, and Group 3 was made up of 24 healthy controls matched by age and weight to Group 2. The prevalence of contralateral knee OA in Groups 1 and 2 was assessed by questionnaire, physical examination, and radiographs, and was compared with findings for Group 3. RESULTS: The rate of OA in all amputees (Groups 1 and 2 together) was 65.6%, which was significantly higher than among the controls (p < 0.05). The most common findings among the amputees were patellar and medial osteophytosis of the tibiofemoral joint, with a tendency to medial narrowing of the tibiofemoral joint space. CONCLUSION: Traumatic amputees have a higher prevalence of OA in the knee of the nonamputated leg than matched healthy controls.

Adult↗

PubMedDate not supplied

Age-related changes of postural control: effect of cognitive tasks.

BACKGROUND: Postural control and falls in the elderly constitute a major health problem. The interest in balance deficits is growing, as concern about the rising costs of health care increases. This issue is particularly relevant to the elderly population in which falls occur most frequently. Postural control in the elderly was studied using a cognitive approach. OBJECTIVE: The purpose of this study was to study the characteristics of central processing of postural control while performing cognitive tasks. METHODS: A dual-task procedure was developed to estimate the level of automaticity of a quiet upright standing task. The effect of a concurrent attention-demanding task (modified Stroop test) on the efficiency of balance control in the elderly was determined using force platform and electromyography measurements. RESULTS: It was found that there is an increase in postural sway in old subjects compared with young subjects when performing single tasks and dual-task tests. The results of the study demonstrate that postural adjustments require cognitive processing; young and old subjects showed similar interference effects on postural steadiness (postural sway) caused by the concurrent attention-demanding task. The results are corroborated by the hypothesis that a dual task gives information on the restoration of automaticity of postural control in old age by a central reorganization process. When performing a dual task tested on a narrow base of support, the old subjects decreased their body sway, while the younger did not. According to electromyography measurements, the older subjects increased their muscle activity in the tibialis anterior and soleus muscles, using slow-twitch motor units compared with the younger subjects. CONCLUSIONS: Both alterations (cognitive and base of support) have a substantially greater effect on the elderly than on the young. The older subjects decreased their body sway by activating a cocontraction strategy of postural control around the ankle joint, probably because of the danger to their postural stability.

Adult↗

PubMedDate not supplied

Effects of regular walking on postural stability in the elderly.

BACKGROUND: Both age and lack of physical activity may be responsible for poor health and poor balance control. Conversely, physical activity may modulate postural control in elderly people. OBJECTIVE: An observational study was performed in older adults to explore whether walking on a regular basis might prove to be beneficial not only to the cardiovascular system but also to maintaining a good balance. METHODS: Twenty-two healthy older subjects walking on a regular basis (DW group) and 121 healthy control older subjects who did not walk regularly (NW group) were studied. The subjects included in the study were free from major gait and postural disorders. An instrumented force platform was used to measure the time-varying displacements of the center of pressure under eight static conditions and postural limit tests. An isometric test was performed to evaluate lower limb muscle strength, and a static two-point discrimination test evaluated the innervation density of the slowly adapting receptors of the sole of the first toe. RESULTS: The DW group had a significantly better (p < 0.05) postural stability under static conditions than the NW group. There were no significant differences in postural limit tests and in two-point discrimination between the groups. The DW group had significantly higher values of ankle plantar flexor and knee extensor strengths, while there were no significant differences in ankle dorsiflexors and knee flexors. None of the DW group reported experiencing a fall during the previous 6 months compared with 16% in the NW group who reported at least two falls during the last half year. CONCLUSIONS: Walking on a regular basis in old age may have the potential to modulate stability. It was found that healthy older subjects, who walked on a regular basis since their retirement, have better postural control, especially in their static balance, than those who do not. The laboratory results were accompanied by the important finding that although older subjects who walk on a regular basis walked much more than nonwalkers, they did not suffer from falls.

Accidental Falls↗