Effects of Neuromuscular Electrical Stimulation Combined with Exercises versus an Exercise Program on the Physical Characteristics and Functions of the Elderly: A Randomized Controlled Trial

The effect of neuromuscular electrical stimulation on the human skeletal muscle transcriptome

AIM

The influence on acute skeletal muscle transcriptomics of neuromuscular electrical stimulation (NMES), as compared to established exercises, is poorly understood. We aimed to investigate the effects on global mRNA-expression in the quadriceps muscle early after a single NMES-session, compared to the effects of voluntary knee extension exercise (EX), and to explore the discomfort level.

METHODS

Global vastus lateralis muscle gene expression was assessed (RNA-sequencing) in 30 healthy participants, before and 3 h after a 30-min session of NMES and/or EX. The NMES-treatment was applied using textile electrodes integrated in pants and set to 20% of each participant's pre-tested MVC mean (±SD) 200 (±80) Nm. Discomfort was assessed using Visual Analogue Scale (VAS, 0-10). The EX-protocol was performed at 80% of 1-repetition-maximum.

RESULTS

NMES at 20% of MVC resulted in VAS below 4 and induced 4448 differentially expressed genes (DEGs) with 80%-overlap of the 2571 DEGs of EX. Genes well-known to be up-regulated following exercise, for example, PPARGC1A, ABRA, VEGFA, and GDNF, were also up-regulated by NMES. Gene set enrichment analysis demonstrated many common pathways after EX and NMES. Also, some pathways were exclusive to either EX, for example, muscle tissue proliferation, or to NMES, for example, neurite outgrowth and connective tissue proliferation.

CONCLUSION

A 30-min NMES-session at 20% of MVC with NMES-pants, which can be applied with an acceptable level of discomfort, induces over 4000 DEGs, of which 80%-overlap with DEGs of EX. NMES can induce exercise-like molecular effects, that potentially can lead to health and performance benefits in individuals who are unable to perform resistance exercise.

Effects of 12 weeks of neuromuscular electrical stimulation of the quadriceps muscles on the function and physio-biochemical traits in functionally fit female nursing-home residents aged 75 + years: a pilot study

PURPOSE

Muscular changes induced by neuromuscular electrical stimulation (NMES) are well recognized, but knowledge of how NMES influences the physio-biochemical traits of the oldest old is still limited. This study investigated the effect of NMES applied for 12 weeks to the quadriceps muscles of female nursing-home residents aged 75 + on their functional capability and inflammatory, bone metabolism, and cardiovascular traits.

METHODS

Nineteen women regularly taking part in two body conditioning sessions per week were randomized into an electrical stimulation group (ES; n = 10; 30 min sessions, 3 times per week) or a control group (CON; n = 9). At baseline and study week 12, all women performed the 30 s chair stand test (30sCST), the 6-minute walk test (6MWT), and the instrumented timed up and go test (iTUG). Resting heart rates, blood pressure, and the blood concentrations of inflammatory and bone metabolism markers were also measured twice.

RESULTS

NMES increased the strength of participants' quadriceps muscles and their performance on the 30sCST and 6MWT while lowering resting arterial blood pressure and inflammatory marker levels; osteoclast activity showed a tendency to decrease. Changes in the iTUG results were not observed. A multiple regression analysis found that the results of functional tests in the ES group were best correlated with pulse pressure (the 30sCST and iTUG tests) and diastolic blood pressure (the 6MWT test).

CONCLUSION

Twelve weeks of NMES treatment improved participants' functional capacity and inflammatory, bone metabolism, and cardiovascular traits. The ES group participants' performance on functional tests was best predicted by hemodynamic parameters.

Concordance between changes in calf circumference and muscle mass exists: A narrative literature review

Technological methods such as BIA or DXA are not always accessible in clinical practice, thus GLIM supports the use of calf circumference measurements to examine muscle mass. However, it has not been described if measurements of calf circumference can detect a change in muscle mass to the same degree as the technological methods. The aim of this study was to assess, whether changes in calf circumference can be used as a valid proxy for changes in muscle mass. 10 studies including measurements of muscle mass by calf circumference and technological methods at baseline and follow-up were identified through a narrative literature review. Results were used to determine concordance between measurements. Predominantly concordance between changes in calf circumference and muscle mass assessed by BIA or DXA was reviled. However, the results were not uniform for hospitalized patients or older adults as groups. Thus, uncertainty whether changes in calf circumference can be used as a valid proxy for changes in muscle mass in these groups still exist.

Resistance band training with functional electrical stimulation improves force control capabilities in older adults: a preliminary study

Resistance band training (RBT) with functional electrical stimulation (FES) may be an effective exercise regimen for improving age-related motor impairments. This preliminary study investigated the potential effects of bimanual RBT with FES on upper limb motor functions in older adults. This study randomly assigned 22 elderly people to the bimanual RBT with FES (Bi-RBT+FES) group and the RBT without FES (Bi-RBT) group. All participants performed isometric hand-grip force control tasks in unimanual (dominant and non-dominant) and bimanual conditions before and after four weeks of exercise for each group. We quantified the mean force, force accuracy, force variability, and force regularity at two targeted force levels (i.e., 10 % and 40 % of maximum voluntary contraction; MVC) to estimate changes in force control capabilities. The results revealed that the Bi-RBT+FES group demonstrated a greater force accuracy in the dominant hand at 10 % of MVC after training. Non-dominant hands in the Bi-RBT+FES group increased force accuracy at 40 % of MVC and reduced force variability collapsed across two targeted force levels. Both groups showed a decrease in force regularity after training. These preliminary results indicate that Bi-RBT+FES may be a viable option to facilitate functional recovery of the upper limbs in older adults.

Effectiveness of exercise interventions on fall prevention in ambulatory community-dwelling older adults: a systematic review with narrative synthesis

Objective

To present a systematic review of randomized controlled trials which summarizes the effects of community-based resistance, balance, and multi-component exercise interventions on the parameters of functional ability (e.g., lower extremities muscle strength, balance performance and mobility).

Methods

This PROSPERO-registered systematic review (registration no. CRD42023434808) followed the PRISMA guidelines. Literature search was conducted in Cochrane, Embase, Ovid Medline, PEDro, Pubmed, Science Direct, Scopus and Web of Science. We included RCTs that investigated the following interventions: lower extremity strengthening, balance and multi-component exercise interventions on ambulatory community-dwelling adults aged ≥65 years.

Results

Lower extremity strengthening exercises revealed significant effects on the strength of lower extremity, balance outcomes and mobility. Balance exercises reduce the rate of injurious falls, improve static, dynamic and reactive balance, lower extremity strength as well as mobility. Multi-component exercise training reduces medically-attended injurious falls and fallers, incidence of falls, fall-related emergency department visits as well as improves mobility, balance, and lower extremity strength.

Conclusion

Physical exercises are effective in improving the components of balance, lower extremity strength, mobility, and reducing falls and fall-related injuries. Further research on fall prevention in low-income countries as well as for older adults in vulnerable context is needed.

Limits of stability and falls during a multicomponent exercise program in faller older adults: A retrospective cohort study

BACKGROUND/OBJETIVES

Multicomponent exercise programs have been demonstrated to prevent falls in older adults. However, the underlying responsible mechanisms are not clear. We aimed to analyze the association between changes in the limits of stability (LOS) as a relevant balance component, and falls occurrence during a multicomponent physical exercise program.

METHODS

Retrospective study, including ninety-one participants who had experienced a fall in the previous year, and were attended in a falls unit. All of them were included in a twice-a-week multicomponent exercise program during 16 weeks. Pre- and post-program measurements were collected for leg press, gait speed, the short physical performance battery (SPPB), and LOS (point of excursion [POE] and maximal excursion [MEX]) with posturography. Falls occurrence was assessed between the beginning and the completion of the exercise program (16 week).

RESULTS

The mean age was 77.2 years, and 72 were female. Thirty-two participants fell at least once during the exercise period. The global baseline POE was 47.6 %, and the MEX was 64.7 %, and there were no differences between fallers and nonfallers. Nonfallers presented greater improvements in POE (6.3 % versus 1.3 %; p < .05) and MEX (9.2 % versus 3.0 %; p < .01) than fallers. The POE and MEX were independently associated with a reduced probability of having had a fall, OR: 0.95 (95 % CI: 0.91 to 0.99) and 0.94 (95 % CI: 0.90 to 0.99), respectively. Changes in SPPB results or leg press strength were not associated with decreased falls. Adjusted probability of fall occurrence decreased by 5 % and 6 % per 1 % improvement in absolute values in POE and MEX, respectively.

CONCLUSIONS

Improvements in LOS after a multicomponent physical exercise program in older adults with previous falls may be associated with a decreased occurrence of falls.

Combined Use of Transcutaneous Electrical Nerve Stimulation and Short Foot Exercise Improves Navicular Height, Muscle Size, Function Mobility, and Risk of Falls in Healthy Older Adults

Electrical stimulation is an established method that is used to improve muscle strength. The present study compared changes in the navicular drop test (NDT), muscle size, the five times sit to stand (5TSTS) test, the timed up and go (TUG) test, and the risk of falls in response to transcutaneous electrical nerve stimulation (TENS) plus short foot exercise (SFE) and SFE alone in 68 healthy elderly participants aged 65−75 years. Participants were randomly assigned to two groups: TENS plus SFE and SFE alone (with sham TENS). Measurements of NDT, muscle size, 5TSTS, TUG, and risk of falls were made before and after 4 weeks of training. The NDT was significantly improved by a median of 0.31 mm in the TENS plus SFE group and 0.64 mm in the SFE alone group (p < 0.001). Similarly, there was a significant improvement in Falls Efficacy Scale International (FES-I), 5TSTS, and TUG for both groups (p < 0.001). The abductor hallucis muscle size increased by 0.23 cm2 in the TENS plus SFE group and 0.26 cm2 in the SFE alone group (p < 0.001). There were no significant differences between the two groups for any variables (p > 0.05) except TUG, which showed a greater improvement in the TENS plus SFE group (p = 0.008). Our findings demonstrated that TENS plus SFE and SFE alone improved intrinsic foot muscle size. However, TENS plus SFE tended to improve NDT more than SFE alone, particularly in cases of severe muscle weakness. Thus, the combined use of TENS plus SFE could be recommended for muscle strengthening and balance programs for fall prevention in older adults.