Calf cutaneous stimulation generates reflexes in the thigh that can be modified by subthreshold noisy vibration.

Imperceptible tactile noise applied to the skin of the feet enhances posture-correcting cutaneous reflexes. This sensory augmentation technique, stochastic resonance (SR), has not been tested in the less-sensitive hairy skin of the leg for its reflex-enhancement ability. The objectives of this study were to determine whether calf skin stimulation produces cutaneous reflexes and whether noise can modify the reflex. In 20 participants, electrotactile pulse trains were applied at the calf while participants performed submaximal isometric knee extension. To test SR, five different levels of vibrotactile noise were applied simultaneously to the test input. Muscle activity from the vastus lateralis (VL) was analyzed 60-110 ms after stimulation. Reflex ratios were calculated by dividing the reflex peak activity by the prestimulation background muscle activity. A significant reflex response was evoked in 16/20 participants (5.41 ± 2.6% of background muscle activity); these responses varied between individuals with eight being facilitatory and eight being inhibitory. In half of the participants, a new reflex appeared at some level of added noise (n = 10). The average reflex ratio of the study population was significantly higher at the "optimal" noise level (8.61 ± 4.5) than at "baseline" (4.70 ± 5.6) (P = 0.002); the optimal level varied across participants. These results suggest that cutaneous reflexes exist at the VL in response to calf skin stimulation and that SR can change cutaneous reflexes at the leg. This study provides an important first step toward SR application in clinical populations with sensory loss such as individuals with lower extremity amputation.NEW & NOTEWORTHY Our work showed that cutaneous reflexes, known to be present in response to foot sole stimulation, can also be evoked by stimulation of hairy leg skin. In addition, we demonstrated that adding tactile noise can enhance this reflex response. These findings demonstrate proof-of-concept for potential future applications where tactile stimulation, applied to the leg of an individual with amputation, can enhance postural-relevant reflexes. Improving postural control may reduce the risk of falls in this high-risk population.

Immobilization protocols for the treatment of cervical spine fracture: a scoping review.

BACKGROUND: Current protocols on cervical immobilization postcervical spine fracture are widely accepted in the acute rehabilitation of older adults, however consensus on its overall effectiveness remains lacking. PURPOSE: Summarize information from original studies on available cervical immobilization protocols following a cervical fracture and to answer the questions; Which types of study designs have been used to assess the effectiveness of these protocols? What are the currently reported cervical immobilization protocols following cervical fracture in adults? What is the effectiveness of these protocols? What adverse events are associated with these protocols? STUDY DESIGN: Scoping review was performed. PATIENT SAMPLE: Searches were performed on the following online databases from inception to February 23, 2023: EMBASE, MEDLINE, CINAHL, and CENTRAL. Databases were searched for articles pertaining to collar use post cervical spine fracture. OUTCOME MEASURES: Effectiveness of the cervical fracture immobilization protocols was the primary outcome, examined by various measures including union rates and disability indexes. METHODS: 4 databases were searched; EMBASE, MEDLINE, Cumulative Index of Nursing and Allied Health Literature (CINAHL), and Cochrane Central Register of Controlled Trials (CENTRAL) beginning on February 23, 2023, where 5,127 studies were yielded and 32 were extracted based on studies of adults (≥18 years) with a diagnosis of a cervical fracture (C0-C7) managed with a rigid external orthosis to prevent instability and surgery (collar, or cervicothoracic orthosis). Risk of bias was assessed using the guidelines set out by the Joanna Briggs Institute. RESULTS: This scoping review yielded low-level prospective (18%) and retrospective (69%) cohort studies, case-control studies (3%), and case series (6%) from 1987 to 2022, patient age ranged from 14 to 104 years. Findings were difficult to summarize based on the lack of randomized controlled trials, leading to no clear conclusions drawn on the presence of standardized cervical immobilization protocols with no information on the duration of treatment or transition in care. Most included articles were retrospective cohort studies of poor to moderate quality, which have significant risk of bias for intervention questions. The effectiveness of these protocols remains unclear as most studies evaluated heterogeneous outcomes and did not present between-group differences. Mortality, musculoskeletal (MSK) complications, and delayed surgery were common adverse events associated with cervical collar use. CONCLUSION: This scoping review highlights the need for higher levels of evidence as there is currently no standardized immobilization protocol for cervical spine fractures as a primary treatment, the effectiveness of cervical immobilization protocols is unclear, and mortality, MSK complications, and delayed surgery are common adverse events. No sources of funding were used for this scoping review.

Remote Subthreshold Stimulation Enhances Skin Sensitivity in the Lower Extremity.

Foot sole skin interfaces with the ground and contributes to successful balance. In situations with reduced sensitivity in the glabrous foot skin, stochastic resonance (SR) improves skin sensitivity by adding tactile noise. Some situations, however, involve an interface comprised of hairy skin, which has higher thresholds for sensitivity. For example, in lower extremity amputation the residual limb is comprised of hairy leg skin. The main objective of this study was to determine if SR improves skin sensitivity in hairy skin, and whether a specific intensity of noise is most effective. Secondary objectives were to compare the effect between locations, ages and modalities. In 60 healthy participants a vibrotactile (test) input was delivered at the lower extremity concurrently with a second, noisy stimulus applied more proximally. The presence of a remote SR effect was tested in 15 young participants using electrotactile noise at the calf. Secondary objectives were tested in separate groups of 15 subjects and differed by substituting for one of the three variables: vibrotactile noise, heel site, and with older participants. A forced-choice protocol was used to determine detection ability of the subthreshold vibration test input with varying noise levels applied simultaneously (0, 20, 40, 60, 80, and 100% of perceptual threshold). An SR effect was identified when increased detection of the input was obtained at any level of noise versus no noise. It was found that all four test groups demonstrated evidence of SR: 33-47% of individuals showed better detection of the input with added noise. The SR effect did not appear consistently at any specific noise level for any of the groups, and none of the variables showed a superior ability to evoke SR. Interestingly, in approximately 33% of cases, threshold values fluctuated throughout testing. While this work has provided evidence that SR can enhance the perception of a vibrotactile input in hairy skin, these data suggest that the ability to repeatably show an SR effect relies on maintaining a consistent threshold.

Impact of Physical Training Programs on Physical Fitness in People With Class II and III Obesity: A Systematic Review and Meta-Analysis.

BACKGROUND: Physical training, regardless of the presence of concurrent weight loss, provides numerous health benefits for individuals who are overweight and obese and have or are at risk for cardiovascular disease. PURPOSE: The purpose of this review was to identify different types of physical training programs (aerobic, resistance, or combined), with or without counseling/diet modifications, and their impact on physical fitness in individuals who have class II and III obesity. DATA SOURCES: Medline and Medline In-Process, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, Web of Science, LILACS, CINAHL, SPORTDiscus, PEDro, and PubMed were searched up to June 2017. STUDY SELECTION: This review had the following inclusion criteria: body mass index of ≥35 kg/m2 and age 18 years or older; supervised physical training program; randomized controlled trial; physical fitness outcome (muscular strength, muscular endurance, cardiovascular endurance, and/or flexibility); in English or Portuguese; and available full-text article. DATA EXTRACTION: Three reviewers independently extracted data, assessed study risk of bias using the Cochrane tool, and discussed disagreements until consensus was reached. DATA SYNTHESIS: Of the 9460 identified articles, 26 were included and 8 were used in a meta-analysis. The meta-analysis showed improvements in walking speed and maximal oxygen uptake but not knee extension strength in the intervention groups. The Cochrane risk-of-bias score indicated that the majority of the data were from randomized controlled trials with a low or unclear risk of bias. LIMITATIONS: The large variability of outcomes and interventions made comparisons difficult. CONCLUSIONS: A combination of aerobic exercise and resistance exercise, in addition to diet modifications, may improve cardiovascular and muscular endurance in individuals with class II and III obesity. However, conclusions must be interpreted with caution because of the heterogeneity in interventions and outcome measures among the studies and an unclear risk of bias in several studies.

A systematic review of the effect of footwear, foot orthoses and taping on lower limb muscle activity during walking and running.

BACKGROUND: External devices are used to manage musculoskeletal pathologies by altering loading of the foot, which could result in altered muscle activity that could have therapeutic benefits. OBJECTIVES: To establish if evidence exists that footwear, foot orthoses and taping alter lower limb muscle activity during walking and running. STUDY DESIGN: Systematic literature review. METHODS: CINAHL, MEDLINE, ScienceDirect, SPORTDiscus and Web of Science databases were searched. Quality assessment was performed using guidelines for assessing healthcare interventions and electromyography methodology. RESULTS: Thirty-one studies were included: 22 related to footwear, eight foot orthoses and one taping. In walking, (1) rocker footwear apparently decreases tibialis anterior activity and increases triceps surae activity, (2) orthoses could decrease activity of tibialis posterior and increase activity of peroneus longus and (3) other footwear and taping effects are unclear. CONCLUSION: Modifications in shoe or orthosis design in the sagittal or frontal plane can alter activation in walking of muscles acting primarily in these planes. Adequately powered research with kinematic and kinetic data is needed to explain the presence/absence of changes in muscle activation with external devices. CLINICAL RELEVANCE: This review provides some evidence that foot orthoses can reduce tibialis posterior activity, potentially benefitting specific musculoskeletal pathologies.