An Evaluation of the Quality of CPR Chest Compressions Performed on Football-Equipped and Obese Simulation Manikins.

OBJECTIVE: Protective athletic equipment may hamper the delivery of effective chest compressions. Unfortunately, an algorithm for managing cardiac arrest emergencies with equipment-laden athletes has yet to be established by national CPR certifying agencies. Further, athletes classified as being overweight or obese carry adipose in the thoracic region, which has been reported to inhibit the ability of rescuers to provide quality chest compressions. Thus, the purpose of this study was two-fold. The first purpose was to assess the ability of emergency responders to perform CPR chest compressions on an obese manikin. The second purpose was to analyze the effect of American football protective equipment on the performance of chest compressions by emergency responders. METHODS: Fifty emergency responders completed four 2-minute bouts of compression-only CPR. The scenarios included performing chest compressions on both traditional and obese CPR manikins, and performing chest compressions over a set of shoulder pads/chest protector that is used in the sport of American football on both traditional and obese manikins. RESULTS: The most notable outcomes in this study were related to chest compression depth, which fell well below the minimum recommended depth published by the American Heart Association in all conditions. Mean compression depth was significantly lower when performed on the obese manikin (avg over pads = 32.8, SD = 9.2 mm; avg no pads = 38.2, SD = 9.1 mm) compared to the traditional manikin (avg over pads = 40.0, SD = 10.9 mm; avg no pads = 40.8, SD = 14.8 mm), with statistical analyses revealing a significant effect due to both manikin size (p < 0.001) and the presence of equipment (p = 0.003), and a statistically significant interaction effect (p = 0.035). Chest recoil data revealed a statistically significant effect due to both manikin size (p = 0.017) and the presence of chest/shoulder safety pads (p = 0.003). CONCLUSION: Within this sample of emergency responders, chest compressions were adversely affected both by the equipment and obesity. Additionally, the traditional manikin received comparable chest compressions regardless of the presence or absence of football protective equipment, albeit both conditions resulted in poor depth performance.

State-Space Model for Arrival Time Simulations and Methodology for Offline Blade Tip-Timing Software Characterization.

Blade tip-timing is an extensively used technique for measuring blade vibrations in turbine and compressor stages; it is one of the preferred techniques used for characterizing their dynamic behaviors using non-contact probes. Typically, arrival time signals are acquired and processed by a dedicated measurement system. Performing a sensitivity analysis on the data processing parameters is essential for the proper design of tip-timing test campaigns. This study proposes a mathematical model for generating synthetic tip-timing signals, descriptive of specific test conditions. The generated signals were used as the controlled input for a thorough characterization of post-processing software for tip-timing analysis. This work represents the first step in quantifying the uncertainty introduced by tip-timing analysis software into user measurements. The proposed methodology can also offer essential information for further sensitivity studies on parameters that influence the accuracy of data analysis during testing.

Experimental Investigation on Hardware and Triggering Effect in Tip-Timing Measurement Uncertainty.

Non-destructive testing for structural health monitoring is becoming progressively important for gas turbine manufacturers. As several techniques for diagnostics and condition-based maintenance have been developed over the years, the tip-timing approach is one of the preferred approaches for characterizing the dynamic behavior of turbine blades using non-contact probes. This experimental work investigates the uncertainty of the time-of-arrival of a Blade Tip-Timing measurement system, a fundamental requirement for numerical and aeromechanical modeling validation. The study is applied to both the measurement setup and the data processing procedure of a generic commercial measurement system. The influence of electronic components and signal processing on the tip-timing uncertainty is determined under different operating conditions.

Examination of Near Point of Convergence Scores in High-School Athletes: Implications for Identifying Binocular Vision Dysfunction After Concussion Injury.

OBJECTIVE: To identify normative near point of convergence (NPC) data for healthy high-school-aged athletes (13-19 years old) and determine the percentage of individuals with NPC scores that fall outside the currently accepted clinical cutoff value of 5 cm. Another objective was to determine the relationship between sex, concussion history, and attention deficit disorder/attention deficit hyperactivity disorder (ADD/ADHD) with NPC scores, if any. DESIGN: Case series. SETTING: High-school sports medicine clinic. PATIENTS OR PARTICIPANTS: Near point of convergence was assessed in 718 high-school student athletes (141 females and 577 males) with an average age of 15.96 ± 1.16 years. INTERVENTIONS: None. MAIN OUTCOME MEASURES: An accommodation convergence ruler was used to measure NPC. Near point of convergence scores were repeated a total of 3 times and the mean used for all statistical analyses. RESULTS: The NPC scores for all participants averaged 3.58 cm, and the intraclass correlation coefficient for the 3 repeated measurements was 0.956. Approximately 20% of mean NPC scores were above the accepted upper limit of 5 cm. Although a statistically significant effect for sex was identified, the difference between them was considered clinically insignificant. No relationship between NPC and history of concussion or ADD/ADHD was identified. CONCLUSIONS: Results indicate that in high-school-aged subjects, approximately 20% of individuals may have NPC values that fall outside the current critical cutoff value and may lead to incorrect diagnosis of ocular dysfunction. In addition, NPC does not seem to be affected by the history of concussion or a diagnosis of ADD/ADHD.

Stimulant Therapy Utilization for Neurocognitive Deficits in Mild Traumatic Brain Injury.

CONTEXT: There are 3.8 million mild traumatic brain injuries (mTBIs) that occur each year in the United States. Many are left with prolonged life-altering neurocognitive deficits, including difficulties in attention, concentration, mental fatigue, and distractibility. With extensive data on the safety and efficacy of stimulant medications in treating attention deficit, concentration difficulties and distractibility seen with attention deficit disorder, it is not surprising that interest continues regarding the application of stimulant medications for the persistent neurocognitive deficits in some mTBIs. EVIDENCE ACQUISITION: Studies were extracted from PubMed based on the topics of neurocognitive impairment, mTBI, stimulant use in mTBI, stimulants, and the association between attention deficit/hyperactivity disorder and mTBI. The search criteria included a date range of 1999 to 2020 in the English language. STUDY DESIGN: Literature review. LEVEL OF EVIDENCE: Level 4. RESULTS: Currently, there is very limited literature, and no guidelines for evaluating the use of stimulant medication for the treatment of prolonged neurocognitive impairments due to mTBI. However, a limited number of studies have demonstrated efficacy and safety of stimulants in the treatment of neurocognitive sequelae of mTBI in the adult, pediatric, military, and athletic populations. CONCLUSION: There is limited evidence to suggest stimulant medication may be beneficial in patients with mTBI with persistent neurocognitive symtpoms. The decision to utilize stimulant medication for mTBI patients remains physician and patient preference dependent. Given the limited encouraging data currently available, physicians may consider stimulant medication in appropriate patients to facilitate the recovery of prolonged neurocognitive deficits, while remaining cognizant of potential adverse effects.

Predicting Concussion Recovery with PHQ-9 and GAD-7.

OBJECTIVE: To determine whether scores obtained from Patient Health Questionnaire-9 (PHQ-9) or the General Anxiety Disorder-7 (GAD-7) instruments administered following a concussion can be used to predict recovery time. METHOD: Retrospective cohort study in a university-based specialty concussion center of 502 concussed participants. Participants completed a PHQ-9 and GAD-7 during their initial visit and subsequent visits during the recovery period (ie, at 14, 28, 56, and 84 days). RESULTS: The median recovery time from a concussion was 21 days from the initial clinical evaluation; however, individuals with a PHQ-9 score ≤ 6 (n = 262) had a median recovery time of 17 (95% confidence interval [CI] 15-19) days, whereas those with PHQ-9 scores >6 (n = 240) had a median recovery time of 33 (95% CI 28-37) days and a hazard ratio of 0.525 (95% CI 0.438-0.629, P < 0.0001). For individuals with a GAD-7 score ≤ 4 (n = 259), the median recovery was 19 (95% CI 17-21), days whereas for those with a GAD-7 score > 4 (n = 243), the median recovery was 32 (95% CI 28-36) days with a hazard ratio of 0.554 (95% CI 0.462-0.664, P < 0.00). CONCLUSIONS: Scores obtained from PHQ-9 and GAD-7 screening tools appear to be predictive of an individual's recovery and may help identify those subjects who may benefit from early psychological interventions.

Bio-mechanical characterization of a CAD/CAM PMMA resin for digital removable prostheses.

OBJECTIVE: To compare the mechanical and biological features of a polymethylmethacrylate (PMMA) disc for CAD/CAM prostheses (test samples, TG) with a traditional resin (control samples, CG). METHODS: Mechanical analysis was performed using Dynamic Mechanical Analysis (DMA) and Brillouin's micro-spectroscopy. Human keratinocyte morphology and adhesion were analyzed by scanning electronic microscopy (SEM), cytotoxicity by the MTT assay, apoptosis by flow cytometry and p53, p21 and bcl2 gene expression by real time PCR. RESULTS: TG exhibited a higher elastic modulus than CG (range 5100-5500 ± 114.3 MPa vs 3000-3300 ± 99.97 MPa). The Brillouin frequency was found at ωB= (15.50 ± 0.05) GHz for TG and at ωB_1 = (15.50 ± 0.05) GHz and ωB_2 = (15.0 ± 0.1) GHz for CG where two peaks were always present independently of the sample point. SEM analysis revealed that keratinocytes on TG disks appeared to be flattened with lamellipodia. Keratinocytes on CG disks rose above the substrate with cytoplasmatic filaments. MTT viability data at 3 h and 24 h showed TG was significantly less cytotoxic than CG (p < 0.001). No significant differences emerged in apoptosis on CG and TG. Real-time PCR showed p53 expression increased after 3 h by about 9-fold in keratinocytes on TG (p < 0.001) and about 5-fold in those on CG (p < 0.001). High p53 expression persisted after 24 h on both disks. No significant variations were observed in p21 and bcl2 expression at any time-point. SIGNIFICANCE: PMMA resins, as used in CAD/CAM technology, displayed suitable biocompatible and mechanical properties for removable prostheses.

Early Aerobic Exercise for the Treatment of Acute Pediatric Concussions.

Sport-related concussion is a common injury that has garnered the attention of the media and general public because of the potential for prolonged acute symptoms and increased risk for long-term impairment. Currently, a growing body of evidence supports the use of various therapies to improve recovery after a concussion. A contemporary approach to managing concussion symptoms is to use aerobic exercise as treatment. To date, several studies on both pediatric and adult patients have established that controlled aerobic exercise is a safe and effective way to rehabilitate patients experiencing delayed recovery after concussion. However, less is known about the utility of an early exercise protocol for optimizing recovery after acute concussion and reducing the risk for persistent postconcussive symptoms, particularly in pediatric populations. Thus, the purpose of our paper was to review and evaluate the available literature on the implementation of aerobic exercise for the treatment of acute pediatric concussion.

Cochlear Implantation in Cochlear Ossification: Retrospective Review of Etiologies, Surgical Considerations, and Auditory Outcomes.

OBJECTIVES: 1) To review the surgical and auditory outcomes and complications of cochlear implantation in cases with cochlear ossification. 2) To evaluate association between the extent and etiology of ossification to outcomes. STUDY DESIGN: Retrospective study. SETTING: Otology and skull base surgery center. SUBJECTS AND METHODS: Charts of 40 patients (42 ears) with cochlear ossification undergoing cochlear implantation were reviewed. Demographic features, operative findings, auditory outcomes, and complications were analyzed. Operative findings included extent of cochlear ossification, extent of drilling required to obtain patent cochlear lumen, approach (posterior tympanotomy/subtotal petrosectomy), electrode insertion (partial/complete, scala tympani/vestibuli), and complications. Auditory outcomes were assessed over a 4-year follow-up period using vowel, word, sentence, and comprehension scores. Patients were divided into groups (otosclerotic/non-otosclerotic and round window/basal turn ossification) for comparison of auditory outcomes. Outcomes were compared with 60 randomly identified controls (adults with postlingual deafness) who underwent implantation with no cochlear ossification. RESULTS: The median age and duration of deafness of patients was 54.39 and 27.15 years, respectively. Etiology of cochlear ossification was otosclerosis in 23 of 42 ears and mixed in 19 of 42 ears (chronic otitis media, temporal bone fractures, idiopathic, meningitis, Cogan's syndrome) with exclusive round window involvement in 54.7% of cases and the rest having partial or complete basal turn ossification. 59.5% ears underwent subtotal petrosectomy for implantation. Three patients underwent scala vestibuli insertion and five had incomplete electrode insertion. Auditory outcomes were comparable in otosclerotic and non-otosclerotic cases and in round window and basal turn ossification cases. No significant differences were observed in auditory scores when compared with controls with no ossification. CONCLUSIONS: Cochlear implantation in cochlear ossification is feasible despite surgical challenges and modifications. Auditory outcomes in basal turn ossification appear to be comparable to cases with no ossification with extent of ossification having no significant association with outcomes.

Fibre Bragg Gratings for the Monitoring of Wooden Structures.

The aim of this work was to develop and validate an experimental methodology suitable for analysing on-site the behaviour of fibre-reinforced wooden structures. The proposed measurement method is based on the application of fibre Bragg grating (FBG) strain sensors. An analysis of adhesive behaviour was performed preliminarily, which provided indications for choosing the type of adhesive and for the fibre bonding length in accordance with the volume of measurement. The first series of tests was carried out on wood samples to verify the coupling between the measuring sensor and the wood support when the latter is subject to mechanical stresses. The second investigation was done on site to test the behaviour of a historical wood floor before and after reinforcement by means of a series of tests performed using optical fibres with the Bragg grating. The optical fibre system measurements were compared to those obtained using a laser vibrometer, a measurement system of proven stability and precision. The comparison makes it possible to confirm the validity of the results and the reliability of the system for the monitoring of historic wooden structures.

Cochlear Implantation in Otosclerosis: Surgical and Auditory Outcomes With a Brief on Facial Nerve Stimulation.

OBJECTIVES: 1) To review the surgical and auditory outcomes in patients of cochlear implantation in otosclerosis. 2) To review complications and postimplantation facial nerve stimulation (FNS). 3) To compare the auditory outcomes between patients displaying cochlear ossification to the nonossified ones. STUDY DESIGN: Retrospective study. SETTING: Quaternary Otology and Skull base surgery center. SUBJECTS AND METHODS: Charts of 36 patients (38 ears) with otosclerosis undergoing cochlear implantation were reviewed from the cochlear implant database. Demographic features, operative findings, auditory outcomes, and postimplantation FNS were analyzed. Operative findings included extent of cochlear ossification, approach (posterior tympantomy/subtotal petrosectomy), electrode insertion (partial/complete, scala tympani/vestibuli), and complications. All the patients underwent implantation using straight electrodes. Auditory outcomes were assessed over a 4-year follow-up period using vowel, word, sentence, and comprehension scores. Patients were divided into two groups (with and without cochlear ossification) for comparison of auditory outcomes. RESULTS: The mean age and duration of deafness of patients was 59.72 and 28.9 years respectively. Twenty-three of 38 ears had cochlear ossification, with exclusive round window involvement in 60% of the patients, with the rest having partial or complete basal turn ossification. 36.8% ears underwent subtotal petrosectomy for cochlear ossification. One patient underwent scala vestibuli insertion and two had incomplete electrode insertion. Patients with no ossification had no intra or postoperative complications. One patient had bilateral FNS managed by alterations in programming strategy. Auditory outcomes in patients without any ossification were better than in patients with ossification, though statistically insignificant in most parameters. CONCLUSION: Cochlear implantation in otosclerosis provides good auditory outcomes, despite high incidence of cochlear ossification. Patients of FNS can be managed by alterations in programming strategy, without affecting auditory outcomes.

Image Analysis Technique for Material Behavior Evaluation in Civil Structures.

The article presents a hybrid monitoring technique for the measurement of the deformation field. The goal is to obtain information about crack propagation in existing structures, for the purpose of monitoring their state of health. The measurement technique is based on the capture and analysis of a digital image set. Special markers were used on the surface of the structures that can be removed without damaging existing structures as the historical masonry. The digital image analysis was done using software specifically designed in Matlab to follow the tracking of the markers and determine the evolution of the deformation state. The method can be used in any type of structure but is particularly suitable when it is necessary not to damage the surface of structures. A series of experiments carried out on masonry walls of the Oliverian Museum (Pesaro, Italy) and Palazzo Silvi (Perugia, Italy) have allowed the validation of the procedure elaborated by comparing the results with those derived from traditional measuring techniques.

Evaluating the Recovery Curve for Clinically Assessed Reaction Time After Concussion.

CONTEXT: A change in reaction time is one of various clinical measures of neurocognitive function that can be monitored after concussion and has been reported to be among the most sensitive indicators of cognitive impairment. OBJECTIVE: To determine the timeline for clinically assessed simple reaction time to return to baseline after a concussion in high school athletes. DESIGN: Observational study. SETTING: Athletic training room. PATIENTS OR OTHER PARTICIPANTS: Twenty-one high school-aged volunteers. INTERVENTION(S): Participants completed 8 trials of the ruler-drop test during each session. Along with baseline measures, a total of 6 additional test sessions were completed over the course of 4 weeks after a concussion (days 3, 7, 10, 14, 21, and 28). MAIN OUTCOME MEASURE(S): The mean reaction times calculated for all participants from each of the 7 test sessions were analyzed to assess the change in reaction time over the 7 time intervals. RESULTS: After a concussion and compared with baseline, simple reaction time was, on average, 26 milliseconds slower at 48 to 72 hours postinjury (P < .001), almost 18 milliseconds slower on day 7 (P < .001), and about 9 milliseconds slower on day 10 (P < .001). Simple reaction time did not return to baseline levels until day 14 postinjury. CONCLUSIONS: Clinically assessed simple reaction time appeared to return to baseline levels within a timeframe that mirrors other measures of cognitive performance (approximately 14 days).

Vector-borne diseases.

After a request from the European Commission, EFSA's Panel on Animal Health and Welfare summarised the main characteristics of 36 vector-borne diseases (VBDs) in https://efsa.maps.arcgis.com/apps/PublicGallery/index.html?appid=dfbeac92aea944599ed1eb754aa5e6d1. The risk of introduction in the EU through movement of livestock or pets was assessed for each of the 36 VBDs individually, using a semiquantitative Method to INTegrate all relevant RISK aspects (MINTRISK model), which was further modified to a European scale into the http://www3.lei.wur.nl/mintrisk/ModelMgt.aspx. Only eight of the 36 VBD-agents had an overall rate of introduction in the EU (being the combination of the rate of entry, vector transmission and establishment) which was estimated to be above 0.001 introductions per year. These were Crimean-Congo haemorrhagic fever virus, bluetongue virus, West Nile virus, Schmallenberg virus, Hepatozoon canis, Leishmania infantum, Bunyamwera virus and Highlands J. virus. For these eight diseases, the annual extent of spread was assessed, assuming the implementation of available, authorised prevention and control measures in the EU. Further, the probability of overwintering was assessed, as well as the possible impact of the VBDs on public health, animal health and farm production. For the other 28 VBD-agents for which the rate of introduction was estimated to be very low, no further assessments were made. Due to the uncertainty related to some parameters used for the risk assessment or the instable or unpredictability disease situation in some of the source regions, it is recommended to update the assessment when new information becomes available. Since this risk assessment was carried out for large regions in the EU for many VBD-agents, it should be considered as a first screening. If a more detailed risk assessment for a specific VBD is wished for on a national or subnational level, the EFSA-VBD-RISK-model is freely available for this purpose.

An Integrated Approach to Characterize the Behavior of a Human Fingertip in Contact with a Silica Window.

Understanding the mechanisms of human tactual perception represents a challenging task in haptics and humanoid robotics. A classic approach to tackle this issue is to accurately and exhaustively characterize the mechanical behavior of human fingertip. The output of this characterization can then be exploited to drive the design of numerical models, which can be used to investigate in depth the mechanisms of human sensing. In this work, we present a novel integrated measurement technique and experimental set up for in vivo characterization of the deformation of the human fingertip at contact, in terms of contact area, force, deformation, and pressure distribution. The device presented here compresses the participant's fingertip against a flat surface, while the aforementioned measurements are acquired and experimental parameters such as velocity, finger orientation, and displacement (indentation) controlled. Experimental outcomes are then compared and integrated with the output of a 3D finite element (FE) model of the human fingertip, built upon existing validated models. The agreement between numerical and experimental data represents a validation for our approach.

Vestibular Schwannoma Resection with Ipsilateral Simultaneous Cochlear Implantation in Patients with Normal Contralateral Hearing.

OBJECTIVE: To report the hearing results of cochlear implantation simultaneous to vestibular schwannoma (VS) resection by means of a translabyrinthine approach in patients with normal contralateral hearing. METHODS: This was a prospective study including adults with sporadic VS. Tumors were resected by means of a modified translabyrinthine approach with preservation of the cochlear nerve. RESULTS: A total of 13 patients underwent cochlear implantation. At 14 months, the mean pure-tone audiogram was 56 dB. The mean speech recognition was 80%. Cochlear implantation provides monaural and binaural benefits in all the conditions tested, including sound localization. CONCLUSIONS: Cochlear implantation can be safely performed simultaneously to VS resection with satisfactory hearing results provided that the cochlear nerve is anatomically intact.

Controlled Laboratory Comparison Study of Motion With Football Equipment in a Destabilized Cervical Spine: Three Spine-Board Transfer Techniques.

BACKGROUND: Numerous studies have shown that there are better alternatives to log rolling patients with unstable spinal injuries, although this method is still commonly used for placing patients onto a spine board. No previous studies have examined transfer maneuvers involving an injured football player with equipment in place onto a spine board. PURPOSE: To test 3 different transfer maneuvers of an injured football player onto a spine board to determine which method most effectively minimizes spinal motion in an injured cervical spine model. STUDY DESIGN: Controlled laboratory study. METHODS: Five whole, lightly embalmed cadavers were fitted with shoulder pads and helmets and tested both before and after global instability was surgically created at C5-C6. An electromagnetic motion analysis device was used to assess the amount of angular and linear motion with sensors placed above and below the injured segment during transfer. Spine-boarding techniques evaluated were the log roll, the lift and slide, and the 8-person lift. RESULTS: The 8-person lift technique resulted in the least amount of angular and linear motion for all planes tested as compared with the lift-and-slide and log-roll techniques. This reached statistical significance for lateral bending (P = .031) and medial-lateral translation (P = .030) when compared with the log-roll maneuver. The lift-and-slide technique was significantly more effective at reducing motion than the log roll for axial rotation (P = .029) and lateral bending (P = .006). CONCLUSION: The log roll resulted in the most motion at an unstable cervical injury as compared with the other 2 spine-boarding techniques examined. The 8-person lift and lift-and-slide techniques may both be more effective than the log roll at reducing unwanted cervical spine motion when spine boarding an injured football player. Reduction of such motion is critical in the prevention of iatrogenic injury.

Supplemental substances derived from foods as adjunctive therapeutic agents for treatment of neurodegenerative diseases and disorders.

Neurodegenerative disorders and diseases (NDDs) that are either chronically acquired or triggered by a singular detrimental event are a rapidly growing cause of disability and/or death. In recent times, there have been major advancements in our understanding of various neurodegenerative disease states that have revealed common pathologic features or mechanisms. The many mechanistic parallels discovered between various neurodegenerative diseases suggest that a single therapeutic approach may be used to treat multiple disease conditions. Of late, natural compounds and supplemental substances have become an increasingly attractive option to treat NDDs because there is growing evidence that these nutritional constituents have potential adjunctive therapeutic effects (be it protective or restorative) on various neurodegenerative diseases. Here we review relevant experimental and clinical data on supplemental substances (i.e., curcuminoids, rosmarinic acid, resveratrol, acetyl-L-carnitine, and ω-3 (n-3) polyunsaturated fatty acids) that have demonstrated encouraging therapeutic effects on chronic diseases, such as Alzheimer's disease and neurodegeneration resulting from acute adverse events, such as traumatic brain injury.

Motion produced in the unstable cervical spine by the HAINES and lateral recovery positions.

STUDY OBJECTIVE: To compare the amount of segmental vertebral motion produced with the lateral recovery position and the HAINES technique when performed on cadavers with destabilized cervical spines. METHODS: The cervical spines of 10 cadavers were surgically destabilized at the C5-C6 vertebral segment. Sensors from an electromagnetic tracking device were affixed to the vertebrae in question to monitor the amount of anterior/posterior, medial/lateral, and distraction/compression linear motion produced during the application of the two study techniques. RESULTS: The statistical analysis of linear motion data did not reveal any significant differences between the two recovery positions. CONCLUSION: At this time, no single version of the recovery position can be endorsed for the spine-injured trauma patient. More research is needed to fully ascertain the safety of commonly used recovery positions.

Practice effects associated with repeated assessment of a clinical test of reaction time.

CONTEXT: Researchers have confirmed that the ruler-drop test could be included as part of a multifaceted concussion-assessment battery and potentially as a way to track recovery from head injury. However, it is unclear if this clinical test of reaction time would be characterized by inconsistent performance because of practice effects. OBJECTIVE: To determine if the ruler-drop test is susceptible to practice effects after serial administration. DESIGN: Descriptive laboratory study. SETTING: Sports medicine research laboratory. PATIENTS OR OTHER PARTICIPANTS: Forty-three persons (age = 21.8 ± 2.6 years). INTERVENTION(S): Ten sessions were completed over 5 weeks. Participants completed 10 trials of the ruler-drop test during each session. MAIN OUTCOME MEASURE(S): The mean reaction times calculated for all participants from each test session were analyzed to determine if there was any meaningful change (ie, improvement) in reaction time over the course of the investigation. RESULTS: Simple reaction time improved (ie, decreased) after repeated administration of the ruler-drop test, and the most pronounced improvement occurred between the first 2 test sessions. Between the first and second test sessions, reaction time decreased by almost 7 milliseconds, and there was an overall improvement of almost 13 milliseconds between the first and tenth sessions. Although the pairwise comparisons between the first and second and the first and third sessions were not significant, the change in mean reaction time between the first session and most of the other sessions was significant. We noted no differences when successive sessions were compared. CONCLUSIONS: To prevent practice-related improvements in reaction time, practitioners should allow at least 1 practice session before recording baseline results on the ruler-drop test.