Background: Anticipatory postural adjustments (APAs) are a feedforward mechanism triggered in advance to a predictable perturbation, to help the individual counteract mechanical effects that the disturbance may cause. Whether or not this strategy is compromised in the elderly is not a consensus in the literature. Methods: In this systematic review with meta-analysis, we investigated aging effects on postural control, based on anticipatory postural adjustments (APAs). We selected 11 eligible articles of the following databases: Lilacs, SciELO, PubMed, Cochrane Central, Embase, and CINAHL, involving 324 research participants, assessing their methodological quality and extracting electromyographic, posturographic, and kinematic measurements. We included studies that investigated the occurrence of APAs in healthy younger and older adults, published before 10th August 2022, in English. Studies involving participant with conditions that may affect balance or that did not report measures of onset or amplitude of electromyography (EMG), COP, or kinematics were excluded. To analyze the aggregated results from these studies, we performed the analysis based on the outcome measures (EMG, COP, or kinematic measures) used in individual studies. We calculated differences between younger and older adult groups as the mean differences between the groups and the estimated effect. Egger’s test was conducted to evaluate whether this meta-analysis had publication bias. Results: Through this review, older adults showed no significant difference in the velocity to perform a movement compared to the younger adults (MD 0.95, 95% CI −0.86, 2.76, I² = 82%), but both muscle onset and center of pressure (COP) onset were significantly more delayed in older than in younger adults: erector spinae (MD −31.44, 95% CI −61.79, −1.09, I² = 95%); rectus abdominis (RA) (MD −31.51, 95% CI −70.58, −3.57, I² = 85%); tibialis anterior (TA) (MD −44.70, 95% CI −94.30, 4.91, I² = 63%); soleus (SOL) (MD −37.74, 95% CI −65.43, −10.05, I² = 91%); gastrocnemius (GAS) (MD −120.59, 95% CI −206.70, −34.49, I² = 94%); quadriceps (Q) (MD −17.42, 95% CI −34.73, −0.12, I² = 0%); biceps femoris (BF) (MD −117.47, 95% CI −192.55, −42.70, I² = 97%); COP onset (MD −45.28, 95% CI −89.57, −0.98, I² = 93%), and COP apa (COPapa) (MD 2.35, 95% CI −0.09, 4.79, I² = 64%). These changes did not seem to be linked to the speed of movement but possibly to age-related physiological changes that indicated decreased motor control during APAs in older adults. Conclusions: Older adults use different postural strategies that aim to increase the safety margin and stabilize the body to perform the movement, according to the requirements imposed, and this should be considered in rehabilitation protocols. Systematic review registration: PROSPERO CRD420119143198

The purpose of this study was to compare transcutaneous electrical nerve stimulation (TENS) and stabilization exercises in an attempt to prevent fatigue and improve muscle activation in patients with lumbar disk herniation associated with low back pain. This study involved 29 patients (age range 25-58 years) randomized into 2 groups: the segmental stabilization group (n = 15), who received stabilization exercises on the transversus abdominis (TrA) and lumbar multifidus muscles; and the TENS group (n = 14), who received electrotherapy. Groups underwent 16 sessions, for 60 minutes, twice per week, and they were evaluated before and after intervention. Pain was measured using a visual analog scale, functional disability using the Oswestry Disability Index, muscle activation and fatigue with electromyography, and patients' ability to contract the TrA with a pressure biofeedback unit. Analyses within and between groups were performed. The stabilization group improved lumbar multifidus fatigue (median frequency [MF] initial [P = .002], MF final [P < .001], MF slope [P = .001], and resistance time [P < .001]), ability to contract the TrA (P < .001), pain (P < .001), and functional disability (P < .001). TENS only was effective for pain (P = .012). Although it relieved pain, TENS was not effective as a single treatment to prevent fatigue, increase TrA contraction, and reduce functional disability in herniated disk patients. Stabilization exercises alone improved all measured outcomes.

Background: Ventilator-associated pneumonia (VAP) is considered the most common nosocomial infection in the intensive care unit (ICU), but its features are not fully known in many hospitals in Brazil. We identified clinical and epidemiological aspects associated with VAP in an intensive care unit (ICU) in a general public hospital in northern Brazil and performed an analytical descriptive prospective cohort study.Methods: We analyzed data from thirty-three patients who developed VAP while in the ICU. Clinical and epidemiological data of patients were obtained and tracheal secretions were submitted to culture. Microbial isolates were identified and evaluated for resistance against antimicrobial agents by using the automated Vitek 2 system.Results: The frequency of VAP was 26.2% in patients submitted to invasive mechanical ventilation for at least 48 hours, and death occurred in 78.8% of cases. Only the presence of comorbidity showed a significant association (P = 0.029) with death. The most commonly found bacteria werePseudomonas aeruginosa, Acinetobacterspp.,and Enterobacteriaceae.We also found a frequency of 54.5% of multiresistant bacteria associated with VAP, and previous antibiotic therapy was used in 97% of patients.Conclusions: VAP in our ICU presented with a high frequency and was mainly caused by multiresistant bacteria. Implementation of rational protocols for the use of antibacterial agents and rapid delivery of culture and susceptibility test results are essential. This may help decrease VAP-related mortality rates by multiresistant bacteria in the ICU.

Chronic low back pain (CLBP) is associated with postural control impairments and is highly prevalent in elderly people. The objective of this study is to verify whether anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) are affected by CLBP in elderly people by assessing their postural control during a self-initiated perturbation paradigm induced by rapid upper arm movement when pointing to a target. The participants’ lower limb muscle onset and center of pressure (COP) displacements were assessed prior to perturbation and throughout the entire movement. T₀ moment (i.e., the beginning of the movement) was defined as the anterior deltoid (DEL) onset, and all parameters were calculated with respect to it. The rectus femoris (RT), semitendinosus (ST), and soleous (SOL) showed delayed onset in the CLBP group compared with the control group: RF (control: − 0.094 ± 0.017 s; CLBP: − 0.026 ± 0.012 s, t = 12, p < 0.0001); ST (control: − 0.093 ± 0.013 s; CLBP: − 0.018 ± 0.019 s, t = 12, p < 0.0001); and SOL (control: − 0.086 ± 0.018 s; CLBP: − 0.029 ± 0.015 s, t = 8.98, p < 0.0001). In addition, COP displacement was delayed in the CLBP group (control: − 0.035 ± 0.021 s; CLBP: − 0.015 ± 0.009 s, t = 3; p = 0.003) and presented a smaller amplitude during APA COP_APA [control: 0.444 cm (0.187; 0.648); CLBP: 0.228 cm (0.096; 0.310), U = 53, p = 0.012]. The CLBP group required a longer time to reach the maximum displacement after the perturbation (control: 0.211 ± 0.047 s; CLBP 0.296 ± 0.078 s, t = 3.582, p = 0.0013). This indicates that CLBP elderly patients have impairments to recover their postural control and less efficient anticipatory adjustments. Our results suggest that people with CLBP have altered feedforward hip and ankle muscle control, as shown from the SOL, ST, and RT muscle onset. This study is the first study in the field of aging that investigates the postural adjustments of an elderly population with CLBP. Clinical assessment of this population should consider postural stability as part of a rehabilitation program.

O objetivo deste estudo foi analisar a interface formada entre o polifluoreto de vinilideno (PVDF - piezelétrico e não piezelétrico) e o tecido ósseo do rato. Foram implantados em 40 ratos, na região intercondiliana do fêmur esquerdo, vinte tubos de PVDF [P(VDF-TrFE)] piezelétricos, (d3h = 2,5 pC/N e capacitância 800 pF/m), e vinte tubos de PVDF não piezelétricos. Os animais de ambos os grupos foram subdivididos em quatro subgrupos, seguidos por 7 dias, 3, 6 e 12 semanas. A interface formada pelos tubos com o tecido ósseo foi estudada por microscopia óptica convencional (MOC) (n=28) e pela microscopia eletrônica de varredura (MEV) por retroespalhamento (n=12). No interior dos tubos de PVDF piezelétricos seguidos por 12 semanas foi constatado, tanto pela MOC como pela MEV por retroespalhamento, crescimento de tecido ósseo. Os resultados indicam que a piezeletricidade teve papel importante na neoformação do tecido ósseo no interior dos tubos piezelétricos. Provavelmente, essa formação óssea foi decorrente ou do efeito eletreto, ou das microdeformações produzidas nos tubos piezelétricos, devido à variação da pressão intra articular do joelho durante a marcha.