The effect of Tai Chi lower extremity exercise on the balance control of older adults in assistant living communities

BACKGROUND

Although Tai Chi (TC) is an evidence-based fall prevention training for older adults, its effective movements remain unclear, which may limit the practice of TC. The purpose of this study was to compare the effectiveness of TC lower extremity exercise (TC LEE), the 8-form Tai Chi (8-form TC), and a stretching control intervention for improving balance and functional mobility among older adults.

METHODS

This was a randomized controlled trial. A total of 102 participants (79 ± 6 years old) were recruited from assisted living facilities. All participants were randomly assigned to the TC LEE (n = 40), 8-form TC (n = 31), and stretching (n = 31) groups in which they received the respective interventions for 16 weeks. The Berg Balance Scale (BBS), Timed Up and Go (TUG) test, and center of pressure (COP) measurements during quiet stance were collected prior to and following the 16-week interventions. Comparisons on all measurements were conducted among all groups.

RESULTS

Significant improvements were found in BBS (P = 0.002), TUG test (P = 0.001), root mean square amplitude of COP displacement in the anterior-posterior (P = 0.001) and medial-lateral (P = 0.001) directions, and average COP speed in the anterior-posterior (P = 0.001) and medial-lateral (P = 0.001) directions after training in the TC intervention groups compared with the stretching group. The upper limit of the 95% confidence interval (CI) of differences in change scores on the BBS (-0.8 - 1.3 points) between the TC LEE group and the 8-form TC group was within equivalence margins (1.8 points), while the upper limit of the 95% CI of differences in change scores on the TUG test (0.1 - 2.1 s) exceeded the equivalence margin (0.7 s) with the TC LEE group having the larger change scores.

CONCLUSION

TC LEE can improve balance and functional mobility in older adults, and may have greater effect than the 8-form TC on improving functional mobility as measured by the TUG test.

TRIAL REGISTRATION

ChiCTR2300070600 retrospectively registered.

The Reduced Adaptability of H-Reflex Parameters to Postural Change With Deficiency of Foot Plantar Sensitivity

Purpose: The project was to examine the influence of peripheral neuropathy (PN) severity on the relationship between Hoffmann-reflex (H-reflex) and postures.

Methods: A total of 34 participants were recruited. H-reflex (H/M ratio and H-index) during prone, standing, and the heel-contact phase of walking was tested, along with foot sole sensitivity.

Results: The participants were divided into three groups based on the severity of the foot sole sensitivity deficit: control, less (LA), and more (MA) affected with both feet 5.07 monofilament test scores ranging 10, 0–5, and 6–9, respectively. A significant group by the posture interaction was observed in the H/M ratio (F_{3.0, 41.9} = 2.904, p = 0.046, η_p² = 0.172). In the control group, the H/M ratio of prone (22 ± 7%) was greater than that of the standing (13 ± 3%, p = 0.013) and heel-contact phase (10 ± 2%, p = 0.004). In the MA group, the H/M ratio of standing (13 ± 3%) was greater than that of the heel-contact phase (8 ± 2%, p = 0.011). The H-index was significantly different among groups (F_2,28 = 5.711, p = 0.008, and η_p²= 0.290). Post hoc analysis showed that the H-index of the control group (80.6 ± 11.3) was greater than that of the LA (69.8 ± 12.1, p = 0.021) and MA groups (62.0 ± 10.6, p = 0.003).

Conclusion: In a non-PN population, the plantar sensory input plays an important role in maintaining standing postural control, while as for the PN population with foot sole sensitivity deficiency, type Ⅰ afferent fibers reflex loop (H-reflex) contributes more to the standing postural control. The H-index parameter is an excellent method to recognize the people with and without PN but not to distinguish the severity of PN with impaired foot sole sensitivity.

The underlying mechanisms of improved balance after one and ten sessions of balance training in older adults

Training improves balance control in older adults, but the time course and neural mechanisms underlying these improvements are unclear. We studied balance robustness and performance, H-reflex gains, paired reflex depression, and co-contraction duration in ankle muscles after one and ten training sessions in 22 older adults (+65 yrs). Mediolateral balance robustness, time to balance loss in unipedal standing on a platform with decreasing rotational stiffness, improved (33%) after one session, with no further improvement after ten sessions. Balance performance, absolute mediolateral center of mass velocity, improved (18.75%) after one session in perturbed unipedal standing and (18.18%) after ten sessions in unperturbed unipedal standing. Co-contraction duration of soleus/tibialis anterior increased (16%) after ten sessions. H-reflex gain and paired reflex depression excitability did not change. H-reflex gains were lower, and soleus/tibialis anterior co-contraction duration was higher in participants with more robust balance after ten sessions, and co-contraction duration was higher in participants with better balance performance at several time-points. Changes in robustness and performance were uncorrelated with changes in co-contraction duration, H-reflex gain, or paired reflex depression. In older adults, balance robustness improved over a single session, while performance improved gradually over multiple sessions. Changes in co-contraction and excitability of ankle muscles were not exclusive causes of improved balance.

Postural stability in athletes: The role of sport direction

BACKGROUND

The bulk of relevant studies compare individual or very few sports and on small samples of athletes. This requires extensive analysing postural stability in various sports.

RESEARCH QUESTION

The main objective of our study was to identify the features of postural stability in a normal vertical stance in athletes of various kinds.

METHODS

This study compares postural stability in a normal bipedal stance with eyes open (EO) and eyes closed (EC) conditions among athletes (n = 936, age: 6-47 years) from different sports and performance level. Postural stability was measured through the center of pressure (COP) sway area (AS) and velocity (VCP) while standing quietly in a normal bipedal position with EO and EC on a stabiloplatform (50 Hz).

RESULTS

The order of VCP-EO increase in athletes compared to Control was as follows: Shooting (-11.3 %, p < .0001) < Football (-10.4 %, p < .0001) < Boxing (-8.7 %, p < .0001) < Cross-Country Skiing (-7.2 %, p < .0001) < Gymnastics (-7.0 %, p < .0001) < Running (-6.9 %, p < .0001) < Team Games Played with Hands (-6.8 %, p < .0001) < Wrestling (-6.3 %, p < .0001) < Tennis (-5.5 %, p = .0004) < Alpine Skiing (-5.4 %, p = .002) < Rowing (-5.0 %, p = .194) < Speed Skating (-4.7 %, p = .004) < Figure Skating (-3.6 %, p = .034) < Control.

SIGNIFICANCE

Practicing any kind of sport was associated with increased postural stability in normal bipedal stance. This is the first study that provides reference values of COP sway and velocity with and without visual control on a stable force platform for different sport groups.

Benefits of tai ji quan practice on neuromuscular functions in older adults: A Systematic Review and meta-analysis

BACKGROUND AND PURPOSE

Tai Ji Quan (TJQ) practice has been recommended for reducing falls in older adults, but a gap exists in our understanding of the neuromuscular mechanisms underlying TJQ practice benefits. This study aims to quantify and validate neuromuscular mechanisms underlying TJQ practice benefits in older adults.

MATERIALS AND METHODS

This review and analysis followed the PRISMA framework. All meta-analyses were performed in R.

RESULTS

For healthy older adults, TJQ practice was found to decrease muscle onset latency. Higher leg muscle activations were found during TJQ gait in comparison to normal gait. A significant interaction between TJQ practice time and age of the cohort was observed in muscle onset latency. For adults with pre-existing health conditions, TJQ practice has similar neuromuscular benefits as conventional rehabilitation methods.

CONCLUSION

Neuromuscular function improvements associated with TJQ practice provide a mechanism for reducing falls in older adults with and without pre-existing health conditions.

Tai Chi exercise can ameliorate physical and mental health of patients with knee osteoarthritis: systematic review and meta-analysis

OBJECTIVE

To systematically review the effects of Tai Chi exercise as a nonpharmacological therapeutic strategy on the physical and mental health in individuals with knee osteoarthritis.

DATA SOURCES

A systematic literature retrieval has been conducted in PubMed, Web of Science, EMbase, CENTRAL, OVID, CINAHL, Physiotherapy Evidence Database, Chinese Biomedical Database and China National Knowledge Infrastructure up to June 2020 to identify the relevant randomised controlled trials (RCTs).

METHODS

Two authors assessed independently the risk of bias using the Cochrane Collaboration's tool. Standardised mean difference (SMD) and 95% CI were calculated and data were combined using the fixed or random-effect model. The strength of evidence was rated with Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

A total of 16 RCTs involving 986 patients with knee osteoarthritis met the established inclusion criteria. The strength of evidence for the main outcomes was low or moderate. The systematic review illustrated the efficacy of Tai Chi exercise in treating and managing knee osteoarthritis. Patients' outcomes practising Tai Chi exercise were improved significantly, including pain (SMD = ‒0.69, 95%CI: ‒0.95 to ‒0.44, P < 0.001), stiffness (SMD = ‒0.59, 95%CI: ‒0.91 to ‒0.27, P < 0.001), physical function (SMD = ‒0.92, 95%CI: -1.16 to ‒0.69, P < 0.001), dynamic balance (SMD = 0.69, 95%CI: 0.38 to 0.99, P < 0.001), physiological and psychological health (SF-36 PCS: SMD = 0.48, 95%CI: 0.28 to 0.68, P < 0.001; SF-36 MCS: SMD = 0.26, 95%CI: 0.06 to 0.45, P = 0.01). No adverse events associated with Tai Chi exercise were reported.

CONCLUSION

Tai Chi exercise was beneficial for ameliorating physical and mental health of patients with knee osteoarthritis and should be available as an alternative non-pharmacological therapy in rehabilitation programmes.

The contribution of small and large sensory afferents to postural control in patients with peripheral neuropathy

Peripheral neuropathy (PN) is a multifarious disorder that is caused by damage to the peripheral nerves. Although the symptoms of PN vary with the etiology, most cases are characterized by impaired tactile and proprioceptive sensation that progresses in a distal to proximal manner. Balance also tends to deteriorate as the disorder becomes more severe, and those afflicted are substantially more likely to fall while walking compared with those who are healthy. Most patients with PN walk more cautiously and with greater stride variability than age-matched controls, but the majority of their falls occur when they must react to a perturbation such as a slippery or uneven surface. The purpose of this study was to first describe the role of somatosensory feedback in the control of posture and then discuss how that relationship is typically affected by the most common types of PN. A comprehensive review of the scientific literature was conducted using MEDLINE, and the relevant information was synthesized. The evidence indicates that the proprioceptive feedback that is conveyed primarily through larger type I afferents is important for postural control. However, the evidence indicates that the tactile feedback communicated through smaller type II afferents is particularly critical to the maintenance of balance. Many forms of PN often lead to chronic tactile desensitization in the soles of the feet and, although the central nervous system seems to adapt to this smaller type II afferent dysfunction by relying on more larger type I afferent reflex loops, the result is still decreased stability. We propose a model that is intended both to help explain the relationship between stability and the smaller type II afferent and the larger type I afferent feedback that may be impaired by PN and to assist in the development of pertinent rehabilitative interventions.

Changes in H-reflex amplitude to muscle stretch and lengthening in humans

Spinal reflex excitability is traditionally assessed to investigate neural adjustments that occur during human movement. Different experimental procedures are known to condition spinal reflex excitability. Among these, lengthening movements and static stretching the human triceps have been investigated over the last 50 years. The purpose of this review is to shed light on several apparent incongruities in terms of magnitude and duration of the reported results. In the present review dissimilarities in neuro-spinal changes are examined in relation to the methodologies applied to condition and measure them. Literature that investigated three different conditioning procedures was reviewed: passive dorsiflexion, active dorsiflexion through antagonists shortening and eccentric plantar-flexors contractions. Measurements were obtained before, during and after lengthening or stretching. Stimulation intensities and time delays between conditioning procedures and stimuli varied considerably. H-reflex decreases immediately as static stretching is applied and in proportion to the stretch degree. During dorsiflexions the inhibition is stronger with greater dorsiflexion angular velocity and at lower nerve stimulation intensities, while it is weaker if any concomitant muscle contraction is performed. Within 2 s after a single passive dorsiflexion movement, H-reflex is strongly inhibited, and this effect disappears within 15 s. Dorsiflexions repeated over 1 h and prolonged static stretching training induce long-lasting inhibition. This review highlights that the apparent disagreement between studies is ascribable to small methodological differences. Lengthening movements and stretching can strongly influence spinal neural pathways. Results interpretation, however, needs careful consideration of the methodology applied.

Tai Chi with mental imagery theory improves soleus H-reflex and nerve conduction velocity in patients with type 2 diabetes

OBJECTIVES

Diabetes is a disease that leads to damage to the peripheral nerves which may eventually cause balance instability. The purpose of this study was to determine the effect of 8 weeks of Tai Chi (TC) training combined with mental imagery (MI) on soleus H-reflex and nerve conduction velocity (NCV) of the sural and superficial peroneal nerves in people with diabetes.

DESIGNS

Quasi-experimental, one group pretest-posttest design.

SETTING

Human Research Laboratory.

INTERVENTIONS

A series of Yang style of Tai Chi classes with mental imagery, one hour, two sessions per week for 8 weeks was done.

MAIN OUTCOME MEASURES

The Activities-specific Balance Confidence (ABC) Scale, Functional Reach Test (FRT), and One Leg Standing Test (OLS) were measured as functional data. Hoffman reflex (H-reflex), and sural and superficial peroneal NCV were measured as main outcomes.

RESULTS

All functional outcomes measures were significantly improved after the intervention (p<0.01). In the H-reflex, there was a significant increase in amplitude (μV) after completing 8 weeks of TC exercise (p=0.02). In the sural nerve, the velocity (p=0.01), amplitude (p=0.01), and latency (p=0.01) were significantly improved between pre and post-test. In the superficial peroneal nerve, significant improvements were observed in (p=0.02) and latency (p=0.01), but not in amplitude (μV) (p>0.05).

CONCLUSIONS

Combining TC intervention with MI theory showed an improvement in the H-reflex and NCV tests, which suggests improved balance and walking stability.

Tai Chi Can Improve Postural Stability as Measured by Resistance to Perturbation Related to Upper Limb Movement among Healthy Older Adults

Purpose. The aim of the study was to examine the effects of Tai Chi (TC) training on postural control when upright standing was perturbed by upper limb movement. Methods. Three groups, TC, Brisk walk (BW), and sedentary (SE), of thirty-six participants aged from 65 to 75 years were recruited from local community centers. Participants performed static balance task (quiet standing for 30 s with eyes open and closed) and fitting task (two different reaching distances X three different opening sizes to fit objects through). During tasks, the COP data was recorded while standing on the force plate. Criteria measures calculated from COP data were the maximum displacement in anterior-posterior (AP) and medial-lateral (ML) directions, the 95% confidence ellipse area (95% area), and the mean velocity. Results. No significant effect was observed in the static balance task. For fitting tasks, the group effect was observed in all directions on COP 95% area (p < 0.05) and the TC group showed reduced area. The tests of subject contrasts showed significant trends for reaching different distances and fitting different openings conditions in all directions, the 95% area, and the mean velocity (p < 0.05). Conclusion. Compared to the other two groups, long-term TC exercise helps in reducing the effects of upper body perturbation as measured by posture sway.

The Effects of Tai Chi Practice With Asynchronous Music on Compliance and Fall-Related Risk Factors in Middle-Aged and Older Women: A Pilot Study

PURPOSE

This study examined whether practicing Tai Chi (TC) along with music can maximize the effects of TC on compliance and fall-related risk factors (Dynamic Gait Index and fear of falling).

DESIGN

A convenient sample was recruited in a community senior center. Eighteen women aged 50 to 84 years (9 White, 9 Black) were block randomly assigned to a TC in silence (TC + S; n = 6) or a TC with music (TC + M; n = 12) class.

METHOD

Thirteen participants (4 in TC + S group, 9 in TC + M group) with completed pre- and posttests were included in the final analysis. Paired t tests were conducted to examine changes within groups over time and analysis of covariance was used to assess group differences.

FINDINGS

After 15 weeks of intervention, balance increased in both groups with significantly higher benefits in the TC + M group ( p < .05). Fear of falling scores improved in TC + M group and compliance rate was higher in this group.

CONCLUSIONS

Practicing TC + M may help increase adherence in White and Black middle-aged and older women, and maximize the effects of TC on fall-related risk factors. Studies with more rigorous study design, including musical considerations, are warranted.

Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies

Background

Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC) is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale “complexity” of postural sway fluctuations.

Objectives

To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults.

Methods

A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience) adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO) and eyes-closed (EC). Anterior-posterior (AP) and medio-lateral (ML) sway speed, magnitude, and complexity (quantified by multiscale entropy) were calculated. Single-legged standing time and Timed-Up–and-Go tests characterized physical function.

Results

At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs), TC-experts (n = 27, age 62.8±7.5 yrs) exhibited greater complexity of sway in the AP EC (P = 0.023), ML EO (P<0.001), and ML EC (P<0.001) conditions. Traditional measures of sway speed and magnitude were not significantly lower among TC-experts. Intention-to-treat analyses indicated no significant effects of short-term TC training; however, increases in AP EC and ML EC complexity amongst those randomized to TC were positively correlated with practice hours (P = 0.044, P = 0.018). Long- and short-term TC training were positively associated with physical function.

Conclusion

Multiscale entropy offers a complementary approach to traditional COP measures for characterizing sway during quiet standing, and may be more sensitive to the effects of TC in healthy adults.

Trial Registration

ClinicalTrials.gov NCT01340365

Effects of Tai Chi on the protracted abstinence syndrome: a time trial analysis

While exercise has been shown to reduce the negative effects of substance withdrawal symptoms, no research has investigated if Tai Chi, a traditional Chinese exercise, has similar effects. Here, we observed the physiological effects of Tai Chi on protracted abstinence syndrome (PAS) in female heroin addicts by comprehensively inspecting their immune system function, complete blood count, hepatic function and renal function. To determine the psychological effects, we used the Hamilton Rating Scale for Depression (HRSD) and the rating scale of heroin withdrawal symptoms. We recruited 70 heroin-addicted young women beginning to undergo withdrawal and randomly assigned them into two groups: one group received one-hour Tai Chi exercise every two days (Tai Chi group, n = 36) and the other group did not (control group, n = 34). Thirty-three patients finished this six-month trial. Numerous significant physiological differences were observed between all heroin-addicted subjects (n = 70) and age-matched healthy individuals (n = 18), suggesting a deleterious effect of drug addiction. There were improvements for certain physical parameters between the Tai Chi group (n = 17) and the control group (n = 16), although the differences were not statistically significant. We observed a small significant difference in psychological effects near the 60-day mark between the two groups. Taken together, our results suggest that Tai Chi might have a positive effect on PAS, which future studies can confirm by using an expanded sample size, longer trial time, and more sensitive and specific indicators of psychological and physiological health.

Efficacy of Tai Chi on pain, stiffness and function in patients with osteoarthritis: a meta-analysis

Background

Whether Tai Chi benefits patients with osteoarthritis remains controversial. We performed a meta-analysis to assess the effectiveness of Tai Chi exercise for pain, stiffness, and physical function in patients with osteoarthritis.

Methods

A computerized search of PubMed and Embase (up to Sept 2012) was performed to identify relevant studies. The outcome measures were pain, stiffness, and physical function. Two investigators identified eligible studies and extracted data independently. The quality of the included studies was assessed by the Jadad score. Standard mean differences (SMDs) and 95% confidence intervals (CIs) were calculated and pooled using a random effects model. The change in outcomes from baseline was compared to the minimum clinically important difference.

Results

A total of seven randomized controlled trials involving 348 patients with osteoarthritis met the inclusion criteria. The mean Jadad score was 3.6. The pooled SMD was −0.45 (95% CI −0.70–−0.20, P = 0.0005) for pain, −0.31 (95% CI −0.60–−0.02, P = 0.04) for stiffness, and −0.61 (95% CI −0.85–−0.37, P<0.00001) for physical function. A change of 32.2–36.4% in the outcomes was greater than the minimum clinically important difference.

Conclusions

Twelve-week Tai Chi is beneficial for improving arthritic symptoms and physical function in patients with osteoarthritis and should be included in rehabilitation programs. However, the evidence may be limited by potential biases; thus, larger scale randomized controlled trials are needed to confirm the current findings and investigate the long-term effects of Tai Chi.

Complexity-based measures inform Tai Chi's impact on standing postural control in older adults with peripheral neuropathy

BACKGROUND

Tai Chi training enhances physical function and may reduce falls in older adults with and without balance disorders, yet its effect on postural control as quantified by the magnitude or speed of center-of-pressure (COP) excursions beneath the feet is less clear. We hypothesized that COP metrics derived from complex systems theory may better capture the multi-component stimulus that Tai Chi has on the postural control system, as compared with traditional COP measures.

METHODS

We performed a secondary analysis of a pilot, non-controlled intervention study that examined the effects of Tai Chi on standing COP dynamics, plantar sensation, and physical function in 25 older adults with peripheral neuropathy. Tai Chi training was based on the Yang style and consisted of three, one-hour group sessions per week for 24 weeks. Standing postural control was assessed with a force platform at baseline, 6, 12, 18, and 24 weeks. The degree of COP complexity, as defined by the presence of fluctuations existing over multiple timescales, was calculated using multiscale entropy analysis. Traditional measures of COP speed and area were also calculated. Foot sole sensation, six-minute walk (6MW) and timed up-and-go (TUG) were also measured at each assessment.

RESULTS

Traditional measures of postural control did not change from baseline. The COP complexity index (mean ± SD) increased from baseline (4.1 ± 0.5) to week 6 (4.5 ± 0.4), and from week 6 to week 24 (4.7 ± 0.4) (p=0.02). Increases in COP complexity-from baseline to week 24-correlated with improvements in foot sole sensation (p=0.01), the 6MW (p=0.001) and TUG (p=0.01).

CONCLUSIONS

Subjects of the Tai Chi program exhibited increased complexity of standing COP dynamics. These increases were associated with improved plantar sensation and physical function. Although more research is needed, results of this non-controlled pilot study suggest that complexity-based COP measures may inform the study of complex mind-body interventions, like Tai Chi, on postural control in those with peripheral neuropathy or other age-related balance disorders.

Effect of skill level on cardiorespiratory and metabolic responses during Tai Chi training

Nowadays, Tai chi chuan (TCC) is practiced by millions worldwide with a range of skill levels. However, the effect of skill level on physiological response to TCC performance has yet to be clarified. In this study, physiological parameters during practicing simplified 24-form TCC were investigated and compared in 10 young high-level (HL) male TCC athletes and 10 ordinary-level (OL) male TCC practitioners with similar age and body size. Significantly higher energy expenditure, heart rate, oxygen uptake and tidal volume were found in HL group than OL group during TCC performance. The respiratory frequency and exhalation time were similar between the two groups during practicing TC; however, significantly less inhalation time was found in HL group (1.02±0.2 s) than OL group (1.12±0.28 s). Our results suggested that skill level may have considerable impact on metabolic and cardiorespiratory responses to TCC performance. TCC practitioners with different skill levels may practice TCC in different ways, which was supposed to lead to distinguishable response between the two groups.

Massage Therapy Produces Short-term Improvements in Balance, Neurological, and Cardiovascular Measures in Older Persons

Background:

Falls are the primary cause of accidental death in older persons, producing increased morbidity, decreased independence, and billions in medical costs annually. Massage therapy (MT) may produce adaptations that decrease risk of falling. If MT can improve stability in older persons, it may provide a new intervention for this issue.

Purpose:

Determine the acute effects of a 60-minute MT treatment on static and functional balance, neurological measures, heart rate, and blood pressure in healthy, older individuals.

Setting:

Laboratory

Research Design:

A 2 by 4 (treatment by time) mixed factorial experimental design for the cardiovascular and postural control variables; independent variables were treatment with two levels (control, MT) and time with four levels (pretreatment baseline, immediate post-treatment, 20-minute post-treatment, 60-minute post-treatment). Neurological measures utilized a 2 by 2 mixed design, with testing conducted pre- and 60-minutes post-treatment.

Participants:

Thirty-five healthy, older volunteers (19 male and 16 female; ages 62.9 ± 4.6).

Intervention:

A 60-minute full-body therapeutic massage. The control group rested quietly in the treatment room.

Main Outcome Measures:

Static (double-legged) and functional (single-legged) postural control with eyes-open and eyes-closed; Hoffmann-reflex measures; heart rate, and systolic and diastolic blood pressure.

Results:

MT significantly decreased rectangular displacement area in both the eyes-open and eyes-closed, double-legged stance conditions (p < 0.05); displacement velocity in both eyes-open conditions (p < .05); and systolic and diastolic blood pressure (p < .05), while increasing heart rate (p < .05). MT also significantly lowered H_max/M_max ratios compared to controls (p = .002). Decreased H_max/M_max measures were correlated to improved stability.

Conclusions:

A single, 60-minute, full-body massage therapy treatment was shown to have a stabilizing effect on measures of static and dynamic balance and physiological factors related to stability in older adults. MT should be investigated as a potential intervention to decrease falls in older individuals.

Effects of homosynaptic depression on spectral properties of H-reflex recordings

The purpose of this study was to determine the effects of homosynaptic depression (HD) on spectral properties of the soleus (SOL) H-reflex. Paired stimulations, separated by 100 ms, were used to elicit an unconditioned and conditioned H-reflex in the SOL muscle of 20 participants during quiet standing. Wavelet and principal component analyses were used to analyze features of the time-varying spectral properties of the unconditioned and conditioned H-reflex. The effects of HD on spectral properties of the H-reflex signal were quantified by comparing extracted principal component scores. The analysis extracted two principal components: one associated with the intensity of the spectra and one associated with its frequency. The scores for both principal components were smaller for the conditioned H-reflex. HD decreases the spectral intensity and changes the spectral frequency of H-reflexes. These results suggest that HD changes the recruitment pattern of the motor units evoked during H-reflex stimulations, in that it not only decreases the intensity, but also changes the types of motor units that contribute to the H-reflex signal.