Technique [Volume 89, Issue 6]

Bilbo faces new challenges, position for 2003 seasonBioengineering complex grows with two new additionsBlue Man Group gives Civic Center Complex RockBreaking the Bubbleby the numbersCouncil Clippings Senate and HouseFaces in the CrowdFall sports look towards new seasonFrom the archives...Gailey decision leaves Ball in top spotGame Boy's Golden Sun unearthed...Improved CRC makes permanent home possible for Tech swim teamsKings of Leon debuts, breaks routine music moldME grad students create robotic helping hand for the deafNews BriefsOUR VIEWS Consensus OpinionOUR VIEWS Hot or NotRange offers predictable Western formulaSport ShortsTech professors: masters in art of textbook writingTech ranks high among universitiesTech's rich history: profiles of athletic alumni in the prosTech students wreck and roll at Six FlagsTen Commandments do not dictate American lawThrough the looking glass...Two BitsVinyl offers comforting mix of lounge, live musicWave of viruses slows campus networkWork on stadium nears completionWriting this is like jumping off a cliffYOUR VIEWS Letters to the Edito

Novel Evidence of Cortical Control in Severe Slip Responses

Slips and falls are a major cause of injury and death in the United States. During a human slip response, an ensemble of muscular activations appear in an attempt to maintain balance and prevent a fall. The slip response has several key events that appear reflexive in nature. Though, the temporal nature of these responses may suggest cortical involvement as well. Indeed, some other forms of postural perturbations have provided evidence of cortical control in the recovery response. However, there is little information regarding cortical contribution to the slip response. PURPOSE: To examine corticospinal activity in lower extremity slip recovery corrective responses across slip severity. METHODS: One hundred participants were recruited for this study, and after exclusions the final analysis included 73 participants. Participant’s lower extremity gait kinematics, kinetics, and electromyography (EMG) on the quadriceps (Q), hamstrings (H), dorsiflexors (TA), and plantarflexors (MG) were collected during normal gait (NG) and an unexpected slip (US). The slip was classified based on slip severity, using heel slip distance, and velocity. Once classified, EMG spectral power was examined in the Piper frequency band between gait trials, and groups using a mixed model analysis of variance. RESULTS: Spectral power showed no differences in NG trials. However, spectral power in the Piper frequency band was increased in the Q and H, during the US trial for severe slips, but not minor slips. For the quadriceps, a significant gait by slip severity interaction was observed (F(1,70) = 9.934, p = 0.002, η2 = 0.124). Simple effects revealed a significant increase in activation between normal gait and unexpected slips for those who experienced hazardous slips (p \u3c 0.001), but no differences for non-hazardous slips (p = 0.364). For the hamstrings, a significant interaction was also observed (F(1,70) = 5.076, p = 0.027, η2 = 0.069). The simple effects revealed a significant increase in activity between gait trials, in the hazardous slips (p = 0.002), but not in the non-hazardous slips (p = 0.651). CONCLUSIONS: We show here novel contributions of the corticospinal pathway to the slip recovery response, particularly in musculature used in the recovery response

Lead Leg Corrective Responses to Varying Slip Severity

Slips and falls account for large rates of injury and mortality in multiple populations. While previous research has examined the corrective responses elicited, it is still unclear which responses may break down during more severe slips. PURPOSE: To examine lead leg slip recovery corrective responses across slip severity following an induced slip. METHODS: One hundred participants were recruited for this study. Participant’s lower extremity gait kinematics and kinetics were collected during normal gait and an unexpected slip. The variables of interest were mean sagittal moments about the ankle, knee, and hip, during stance phase. Peak moments, and time to peak moments. The slip was classified based on slip severity, using heel slip distance, and velocity. Once classified, corrective responses were examined between groups using independent t-tests. Additionally, prediction equations for slip severity were created using a binary logistic regression model. RESULTS: After exclusions, the final sample included 64 participants for analyses, consisting of 37 non-hazardous slips, and 27 hazardous slips. The results from the logistic regression model suggest that as the average ankle moment increases in the slip period, the odds of experiencing a hazardous slip decrease (OR = 0.01, CI: 0.01-0.03). Further, as the time to peak hip extension (OR = 1.007, CI: 1.000-1.013) and knee extension moments (OR = 1.001, CI: 0.997-1.004) increase, the odds of experiencing a hazardous slip increase. CONCLUSIONS: Rapid lower extremity corrective responses appear critical in arresting the slip. While there are various strategies for slip recovery, our findings suggest that the primary recovery mechanism at the slipping hip may play a vital role in preventing the severe slip

Examination of the Influence of Lead Leg Recovery Mechanics on Slip Induced Outcomes

INTRODUCTION: Slips and falls have serious implications on one’s health. Nearly every 10 seconds, an adult is treated in the hospital for fall related issues. Further, injury and mortality rates are on the rise across all populations when slips or falls are involved. Other studies have analyzed different corrective responses. However, how the recovery response may fail during a slip that results in a fall is still unclear. PURPOSE: To examine lead leg slip recovery corrective responses between falls and recoveries following an induced slip perturbation. METHODS: One hundred participants were recruited for this study. Participant’s lower extremity gait kinematics and kinetics were collected during normal gait and an unexpected slip. The variables of interest were mean sagittal moments about the ankle, knee, and hip, during stance phase. Peak moments, and time to peak moments. The slip was classified as either a fall or a recovery. Once classified, corrective responses were examined between groups using independent t-tests. Additionally, prediction equations for slip outcome were created using a binary logistic regression model. RESULTS: After exclusions, the final analysis included 64 participants, this included 39 trials classified as recoveries, and 25 trials classified as falls. The results from the logistic regression model suggest that increased time to peak hip extension (OR = 1.006, CI: 1.00-1.01) and ankle dorsiflexion (OR = 1.005, CI: 1.00-1.01) moments increased the odds of falling. While the average ankle moment was negatively associated with falling (OR = 0.001, CI: 0.001-0.005). CONCLUSIONS: After analyzing lower extremity gait during unexpected slip perturbations the results suggest that the slipping hip’s recovery response is a key factor in preventing falls. Future work focused on slip training may benefit from targeting this primary hip response of the slipping leg in order to mitigate fall risk

The Effects of Postural Control Measures on Induced Slip Outcomes

Slips and falls are a major health concern in the United States. Injury incidence rates have increased in recent years and now the leading cause of non-fatal injuries and the third leading cause of fatal injuries in the U.S. are due to falls. During an unexpected slip, sensory information is used to elicit an appropriate recovery. Therefore, increased fall risk has been associated with declines in sensory system integrity. Previous research has suggested that decreased balance scores were associated with more hazardous slips yet measures of postural control between individuals who fall or recover after an induced slip have not been investigated. PURPOSE: To examine differences in slip detection using postural control measures between individuals who fall or recover after an induced slip. METHODS: One hundred participants were recruited for this study. Standing postural control measures were recorded under six different sensory conditions: eyes open, eyes closed, eyes open with sway referenced vision, eyes open with sway referenced support, eyes closed with sway referenced support, and eyes open with sway referenced vision and support. Variables of interest were sway velocity components and the root mean square of the center of pressure (CoP) in the medial-lateral and anterior-posterior directions. After postural control testing, participants completed testing involving a normal gait and an unexpected slip trial. The slip was classified as either a fall or a recovery. Once classified, standing postural control measures were examined between groups using independent t-tests. Additionally, prediction equations for slip outcome were created using a binary logistic regression model. RESULTS: The final analysis sample included 73 participants, with 48 trials classified as recoveries and 25 trials as falls. Postural sway when the proprioceptive (OR = 0.02, 95% CI: 0.01-1.34) and vestibular (OR = 0.60, 95% CI: 0.26-1.39) systems were relied on were negatively associated with odds of falling while visual system reliance resulted in a positive association (OR = 3.18, 95% CI: 0.887-11.445). CONCLUSIONS: The data suggests that visual sensory information may have a greater influence on dynamic stability and slip outcomes. Additionally, postural control measures may provide insight into task selection during recovery

International Finance and Economics Review (InFER) - Issue no. 4 (June 2020)

InFER articles focus on economic theories and the capstone papers highlight data driven analyses that make inferences to business and policy decisions