Comparison of bone density on the dominant and nondominant sides between healthy elderly individuals and stroke patients

The clinical necessity of a distal forearm DEXA scan for predicting distal radius fracture in elderly females: a retrospective case-control study

BACKGROUND

Recent studies have demonstrated that the distal forearm dual-energy X-ray absorptiometry (DEXA) scan might be a better method for screening bone mineral density (BMD) and the risk of a distal forearm fracture, compared with a central DEXA scan. Therefore, the purpose of this study was to determine the effectiveness of a distal forearm DEXA scan for predicting the occurrence of a distal radius fracture (DRF) in elderly females who were not initially diagnosed with osteoporosis after a central DEXA scan.

METHODS

Among the female patients who visited our institutes and who were over 50 years old and underwent DEXA scans at 3 sites (lumbar spine, proximal femur, and distal forearm), 228 patients with DRF (group 1) and 228 propensity score-matched patients without fractures (group 2) were included in this study. The patients' general characteristics, BMD, and T-scores were compared. The odds ratios (OR) of each measurement and correlation ratio among BMD values of the different sites were evaluated.

RESULTS

The distal forearm T-score of the elderly females with DRF (group 1) was significantly lower than that of the control group (group 2) (p < 0.001 for the one-third radius and ultradistal radius measurements). BMD measured during the distal forearm DEXA scan was a better predictor of DRF risk than BMD measured during the central DEXA (OR = 2.33; p = 0.031 for the one-third radius, and OR = 3.98; p < 0.001 for the ultradistal radius). The distal one-third radius BMD was correlated with hip BMD, rather than lumbar BMD (p < 0.05 in each group).

CONCLUSION

Performing a distal forearm DEXA scan in addition to a central DEXA scan appears to be clinically significant for detecting the low BMD in the distal radius, which is associated with osteoporotic DRF in elderly females.

LEVEL OF EVIDENCE

III; case-control study.

Rhythmic Haptic Cueing for Gait Rehabilitation of People With Hemiparesis: Quantitative Gait Study

Background

Rhythm, brain, and body are closely linked. Humans can synchronize their movement to auditory rhythms in ways that can improve the regularity of movement while reducing perceived effort. However, the ability to perform rhythmic movement may be disrupted by various neurological conditions. Many such conditions impair mechanisms that control movement, such as gait, but typically without rhythmic perception being affected. This paper focuses on hemiparetic stroke, a neurological condition that affects one side of the body. Hemiparetic stroke can cause severe asymmetries in gait, leading to numerous physical problems ranging from muscle degeneration to bone fractures. Movement synchronization via entrainment to auditory metronomes is known to improve asymmetry and related gait problems; this paper presents the first systematic study of entrainment for gait rehabilitation via the haptic modality.

Objective

This paper explores the gait rehabilitation of people with hemiparesis following a stroke or brain injury, by a process of haptic entrainment to rhythmic cues. Various objective measures, such as stride length and stride time, are considered.

Methods

This study is a quantitative gait study combining temporal and spatial data on haptically cued participants with hemiparetic stroke and brain injury. We designed wearable devices to deliver the haptic rhythm, called Haptic Bracelets, which were placed on the leg near the knee. Spatial data were recorded using a Qualisys optical motion capturing system, consisting of 8 optoelectronic cameras, and 20 markers placed on anatomical lower limb landmarks and 4 additional tracking clusters placed on the right and left shank and thigh. Gait characteristics were measured before, during, and after cueing.

Results

All 11 successfully screened participants were able to synchronize their steps to a haptically presented rhythm. Specifically, 6 participants demonstrated immediate improvements regarding their temporal gait characteristics, and 3 of the 6 improved their gait in terms of spatial characteristics.

Conclusions

Considering the great variability between survivors of stroke and brain injury and the limited number of available participants in our study, there is no claim of statistical evidence that supports a formal experimental result of improved gait. However, viewing this empirical gait investigation as a set of 11 case studies, more modest empirical claims can be made. All participants were able to synchronize their steps to a haptically presented rhythm. For a substantial proportion of participants, an immediate (though not necessarily lasting) improvement of temporal gait characteristics was found during cueing. Some improvements over baseline occurred immediately after, rather than during, haptic cueing. Design issues and trade-offs are identified, and interactions between perception, sensory deficit, attention, memory, cognitive load, and haptic entrainment are noted.

Vertical ground reaction force during standing and walking: Are they related to bone mineral density left-right asymmetries?

Osteoporosis is a systemic skeletal disease that is characterized by reduced bone mass, deterioration of bone tissue and skeletal fragility. The purpose of the current study was to determine whether asymmetrical femur bone mineral density (BMD) is associated with asymmetrical gait and standing. We compared measures of gait and standing asymmetry in subjects with (n=38) and without (n=11) significant left-right differences in BMD. Participants walked for 72m at their comfortable speed and stood quietly for 60s while outfitted with pressure-sensitive insoles. Based on the pressure measurements, indices of standing and gait asymmetry were determined. Gait Asymmetry (GA) indices of maximum ground reaction force (GRF) and stance time were significantly higher in the asymmetrical BMD group, compared to the symmetrical group (p<0.03). During quiet standing, maximal GRF was twice as high in those with BMD asymmetry, compared to those without, although this difference was not statistically significant (p=0.10). These preliminary findings indicate that femur BMD asymmetry and gait asymmetry are interrelated in otherwise healthy adults. Nutrition, metabolism and lifestyle are known contributors to BMD; typically, they affect bone health symmetrically. We suggest, therefore, that the BMD asymmetry may be due to previous changes in the loading pattern during walking that might have led to asymmetric bone deterioration. Future larger scale and prospective studies are needed to identify the mechanisms underlying the relationship between standing, gait and BMD and to explore whether gait training and exercises that target gait symmetry might help to reduce BMD asymmetry.