Feedback: an essential element of student learning in clinical practice

Clinical practice is an essential component of the nursing curriculum. In order for the student to benefit fully from the experience regular performance feedback is required. Feedback should provide the student with information on current practice and offer practical advice for improved performance. The importance of feedback is widely acknowledged however it appears that there is inconsistency in its provision to students. The benefits of feedback include increased student confidence, motivation and self-esteem as well as improved clinical practice. Benefits such as enhanced interpersonal skills and a sense of personal satisfaction also accrue to the supervisor. Barriers to the feedback process are identified as inadequate supervisor training and education, unfavourable ward learning environment and insufficient time spent with students. In addition to the appropriate preparation of the supervisor effective feedback includes an appreciation of the steps of the feedback process, an understanding of the student response to feedback and effective communication skills.     

Kinematic and electromyographic parameters of the cervical flexion–relaxation phenomenon: The effect of trunk positioning

BackgroundThe cervical flexion–relaxation phenomenon (FRP) is a neck extensor myoelectric “silence” that occurs during complete cervical flexion. The aim of this study was to assess the presence of this phenomenon in the cervical region and to explore the kinematics and EMG parameters in two different experimental conditions.Patients and methodsNineteen young healthy adults (22.2 ± 2.4 years), without any cervical pain history, participated in this study and performed each of the experimental conditions. They had to accomplish a cervical flexion from a neutral seated position and from a 45° forward leaning seated position. Neck kinematics was assessed using a kinematic capture device in order to assess onset and cessation angle of the PFR. Cervical paraspinal and trapezius muscles EMG activities were also recorded. All data were compared in order to assess the differences between the two experimental conditions.ResultsEighteen of the nineteen subjects showed a FRP. The phenomenon appears between 72.6 and 76.3% of maximal cervical flexion and disappears during the return to neutral position between 91.9 and 93.1% of maximal cervical flexion. The FRP was observed, at least unilaterally, in 84.2% (67.4% bilaterally) of tasks without forward bending of trunk, and 90.5% (79.0% bilaterally) of tasks with 45° forward bending of trunk. A significant increase in the flexion–relaxation ratio was observed in the 45° forward leaning condition. No significant difference could be observed between the two experimental conditions for the kinematics parameters.ConclusionThe results of the present study indicate that cervical spine flexion in healthy subjects is characterized by a flexion–relaxation response. Moreover, the results indicate that trunk inclination might facilitate the evaluation of the cervical FRP.     

Transcutaneous respiratory electromyographic monitoring

The integrated diaphragm electromyogram (EMG) signal reflects function from the inspiratory centers to the neuromuscular junction. The feasibility and potential value of transcutaneous diaphragm electromyography (tcEMG) was confirmed in a group of infants using two prototype respiratory EMG monitors. Infants were monitored continuously for periods ranging from hours to days. One hundred were monitored for clinical reasons, looking for disordered respiratory behavior, while 47 were studied for technical/experimental reasons. Reliable measurements of diaphragm EMG activity were obtained, provided fully shielded electrode cables were used. Measurements in 28 ventilated infants and one adult confirmed that, unlike impedance and other non-electrophysiologic measures, tcEMG monitoring is not contaminated by ventilator-induced respiratory movements. The potential value of tcEMG monitoring in ventilated subjects is exemplified by illustrations of: diaphragmatic inactivity from phrenic nerve injury, inadequate central drive, and neuromuscular block; augmented expiratory muscle activity; and progressive increase in inspiratory diaphragmatic activity in the presence of a tension pneumothorax. TcEMG monitoring should prove a worthwhile addition to the available noninvasive respiratory monitoring techniques.     

Time course analysis of the effects of botulinum toxin type a on elbow spasticity based on biomechanic and electromyographic parameters

Lee H-M, Chen J-JJ, Wu Y-N, Wang Y-L, Huang S-C, Piotrkiewicz M. Time course analysis of the effects of botulinum toxin type A on elbow spasticity based on biomechanic and electromyographic parameters.

Objective

To quantify changes of elbow spasticity over time after botulinum toxin type A (BTX-A) injection in the upper extremity of stroke patients.

Design

Before-after trial in which the therapeutic effects were followed up at 2, 6, and 9 weeks after the BTX-A injection (Botox).

Setting

Hospital.

Participants

Chronic stroke patients (N=8) with upper-limb spasticity.

Intervention

BTX-A was injected in upper-limb muscles, including the biceps brachii.

Main Outcome Measures

Treatment effects were quantified as the changes in the velocity and the length dependence of hyperexcitable stretch reflexes. Manual sinusoid stretches of the elbow joint at 4 frequencies (1/3, 1/2, 1, 3/2Hz) over a movement range of 60° were performed on patients by using a portable device. The Modified Ashworth Scale (MAS), biomechanic viscosity, and the reflexive electromyography threshold (RET) of the biceps brachii were used to evaluate the degree of hypertonia.

Results

The statistical analyses of the MAS score, biomechanic viscosity, and RET revealed a significant decrease in spasticity after the injection (all P<.05). Moreover, our quantitative parameters (biomechanic viscosity, RET) revealed small changes in spasticity after the BTX-A injection that could not be observed from clinical MAS evaluations. Five of 8 subjects showed a maximal reduction in spasticity (in terms of biomechanic viscosity value) within 6 weeks after the injection, whereas it was notable that all subjects exhibited peak RET values at either 2 or 6 weeks after the injection with variable degrees of relapse of spasticity.

Conclusions

Early relapse of spasticity (within 9 weeks of the injection) can be detected from biomechanic and neurophysiologic assessments in a clinical setup. These quantitative indices provide valuable information for clinicians when making decisions to perform additional rehabilitation interventions or another BTX-A injection in the early stages of treatment.     

Effects of electromyographic processing methods on computer-averaged surface electromyographic profiles for the gluteus medius muscle

The objective of this study was to demonstrate how two different linear envelope detectors, as used in the quantification of surface electromyographic (EMG) signals, can lead to differences in the properties of observed computer-averaged EMG profiles. Eight healthy male subjects, aged 24 to 32 years, participated in the study. Computer-averaged EMG profiles for the gluteus medius muscle were recorded at a free-walking cadence and at stepping frequencies of 78 and 120 steps/min, using detectors with 3- and 25-Hz cutoff frequencies simultaneously. The 3-Hz filtered EMG profiles proved to be smoother, to exhibit a significantly lower cycle-to-cycle variability, and to have a greater time lag with respect to the original unprocessed EMG signal than the 25-Hz filtered EMG profiles. The observed intersubject variability also was lower for the 3-Hz filtered EMG profiles than for the 25-Hz filtered EMG profiles. The results indicate that comparison of EMG profiles recorded with different detectors is difficult. A standard detector may solve this difficulty.     

Computerized synthesis of electromyographic interference patterns

Computer simulation is a process that appears to have wide application in many disciplines. Electromyographic (EMG) interference patterns can be computer-synthesized by inputting parameters of individual motor unit action potentials (MUAPs) such as amplitude, duration, and phases, and recruitment parameters of number of motor units, and the firing rate and its standard deviation. The resulting simulated EMG interference patterns can then be used to test hypotheses regarding the effect of alteration of the individual MUAP parameters on the interference pattern. An example of the usefulness of simulation is demonstrated by the analysis of the simulated patterns by the Fast Fourier Transform (FFT), which indicates that the major frequency band in the FFT results from the duration of the individual phases of the MUAP. The motor unit's recruitment rate is superimposed on the FFT envelope in the low-frequency end. The variability of the firing rate influences the distinctness of the low-frequency peaks. The MUAP amplitude and number of motor units in the recruitment pattern are reflected in the FFT power. Simulation appears to be a useful tool for further investigation and development of EMG signal analysis techniques.     

Feedback

The emergency department provides a rich environment for diverse patient encounters, rapid clinical decision making, and opportunities to hone procedural skills. Well-prepared faculty can utilize this environment to teach residents and medical students and gain institutional recognition for their incomparable role and teamwork. Giving effective feedback is an essential skill for all teaching faculty. Feedback is ongoing appraisal of performance based on direct observation aimed at changing or sustaining a behavior. Tips from the literature and the author's experience are reviewed to provide formats for feedback, review of objectives, and elements of professionalism and how to deal with poorly performing students. Although the following examples pertain to medical student education, these techniques are applicable to the education of all adult learners, including residents and colleagues. Specific examples of redirection and reflection are offered, and pitfalls are reviewed. Suggestions for streamlining verbal and written feedback and obtaining feedback from others in a fast-paced environment are given. Ideas for further individual and group faculty development are presented.     

肯尼迪病的临床及肌电图分析

目的总结肯尼迪病的临床特征及肌电图表现,为早期诊断提供依据。方法回顾性分析2016年6月至2019年4月于中国医科大学附属盛京医院就诊的5例肯尼迪病患者的资料,所有患者均行肌电图检查。结果本组病例于就诊时均伴有肢体无力表现,但首发症状不尽相同。多数病例于就诊时临床症状主要表现为蹲起不能、上楼费力、行走困难、双上肢上举困难等。肌电图检查:4例患者出现感觉神经不同程度的波幅降低甚至不能引出,速度正常或轻度减慢。1例患者感觉神经传导速度及波幅正常。4例患者存在运动神经传导波幅降低,速度正常或轻度减慢。1例患者出现正中神经、胫神经F波出现率降低。5例患者四肢肌肉静止时可见少量自发电位,轻收缩及大力募集时存在广泛神经源性损害。肌电图检查时神经传导出现以感觉神经波幅受累为主,肌电图检查自发电位少,伴有肌肉神经源性损害时,结合相关临床表现,考虑肯尼迪病的可能。结论肌电图检查是一项方便、快捷的检查,对肯尼迪病可以起到很好的诊断及鉴别诊断的作用。     

Idiopathic scoliosis: an electromyographic study

Thirty-one patients from 12 to 19 years of age having idiopathic scoliosis underwent electromyography of the paraspinal musculature using a Teflon-coated monopolar electrode. The studies conducted with the patients both prone and standing revealed no abnormalities on electrode insertion suggestive of a neuropathic process. In the prone position 29 patients had electrical silence on both the concave and convex side of the curvature. In the standing position most of the patients had asymmetrical activity with a preponderance of activity on the convex side. However, 33% of the patients in whom the spinal musculature was silent in the standing position had balanced curves. This observed correlation between a balanced curve and electrical silence warrants further study.