The authors have presented an unpublished manuscript by Nikolai Aleksandrovich Bernstein written in the form of a diary in 1949. Bernstein focused on the concept of time as a coordinate in four-dimensional space and discussed a variety of issues, including the definition of time, its measurement, time travel, asymmetry of the past and future, and even linguistics. In particular, he offered a definition of life tightly linked to the concept of time. Overall, this manuscript offers a glimpse into Bernstein’s thinking, his sense of humor, and his sarcasm, intimately coupled with the very serious attitude to scientific discourse.
Mark L. Latash and Vera L. Talis
Ali Brian, Sally Taunton Miedema, Jerraco L. Johnson, and Isabel Chica
Fundamental motor skills (FMS) are an underlying mechanism driving physical activity behavior and promoting positive developmental trajectories for health. However, little is known about FMS of preschool-aged children with visual impairments (VI). The purpose of this study was to examine the FMS of preschool-aged children (N = 25) with (n = 10) and without (n = 15) VI as measured using the Test of Gross Motor Development-3. Children without VI performed significantly higher than their peers for locomotor (M = +11.87, p = .014, η2 = .31) and ball skills (M = +13.69, p < .001, η2 = .56). Regardless of the presence of a VI, many participants struggled with developing FMS, with the greatest disparity resting within ball skills. These findings help to clarify the FMS levels of preschool-aged children with VI. Thus, there is a need for both further inquiry and intervention for all children.
John H. Challis
Abdulaziz Almudhi and Hamayun Zafar
The current study was carried out with the aim of investigating the effect of maximally relaxed lying posture on disfluencies in young adults who stutter. A total of 24 participants (17 males, seven females; mean age = 24.9 ± 6.2 years) with developmental stuttering were a part of the study. The participants were asked to perform spontaneous speaking and reading aloud tasks in standard sitting and maximally relaxed lying postures. The severity of stuttering for the studied postures was estimated by using the Stuttering Severity Instrument. The results on the Stuttering Severity Instrument showed that stuttering parameters improved during the maximally relaxed lying posture compared with the standard sitting position. The results are discussed in the light of motor control concepts. It is concluded that the maximally relaxed lying posture can facilitate improvement in stuttering scores during spontaneous speaking as well as reading aloud in young adults who stutter. Reduced stuttering scores in the maximally relaxed lying posture suggest that speech therapists can position participants in this position while treating people who stutter.
Jenna Morogiello and Rebekah Roessler
A healthy 19-year-old male (body mass = 68.04 kg, height = 175.26 cm) participating in a collegiate intramural flag football tournament presented with unilateral gastrocnemius exercise-associated muscle cramps. He was given electrolytes, stretched, and returned to play. The exercise-associated muscle cramps progressed to his quadriceps bilaterally within 23 min of initial reported symptoms. Emergency medical services was activated and the patient was transported by ambulance to the emergency department, where he was diagnosed with acute exertional rhabdomyolysis. This case report explores the rarity of exertional rhabdomyolysis in a noncontact intramural sport and highlights the necessity for early recognition and treatment.
Patricia R. Roby, Robert C. Lynall, Michael J. Cools, Stephen W. Marshall, Janna C. Fonseca, James R. Stevens, and Jason P. Mihalik
We report on hyperbaric oxygen (HBO2) therapy used to improve postinjury outcomes in eight acutely concussed high school student-athletes (5 males, 3 females, mean age = 16.0 ± 1.2 years). Patients were randomly assigned into one of three intervention groups: (a) HBO2 therapy; (b) hyperbaric therapy with compressed medical-grade air (HBA); or (c) normobaric 100% O2 therapy. All patients completed five 1-hr treatments within the first 10 days following his or her concussion. Main outcome measures included mental status examination, symptom burden, and the number of days from injury until the physician permitted the student-athlete to return to activity. Patients receiving HBO2 treatment experienced the greatest absolute symptom reduction over the five treatment sessions. No meaningful differences were found in mental status examination. All participants returned to activity in a similar timeframe. HBO2 therapy may be an effective option for the acute treatment of postconcussion symptoms, particularly in young athletes presenting with a high symptom burden.
Chuyi Cui, Brittney Muir, Shirley Rietdyk, Jeffrey Haddad, Richard van Emmerik, and Satyajit Ambike
Tripping while walking is a main contributor to falls across the adult lifespan. Trip risk is proportional to variability in toe clearance. To determine the sources of this variability, the authors computed for 10 young adults the sensitivity of toe clearance to 10 bilateral lower limb joint angles during unobstructed and obstructed walking when the lead and the trail limb crossed the obstacle. The authors computed a novel measure—singular value of the appropriate Jacobian—as the combined toe clearance sensitivity to 4 groups of angles: all sagittal and all frontal plane angles and all swing and all stance limb angles. Toe clearance was most sensitive to the stance hip ab/adduction for unobstructed gait. For obstructed gait, sensitivity to other joints increased and matched the sensitivity to stance hip ab/adduction. Combined sensitivities revealed critical information that was not evident in the sensitivities to individual angles. The combined sensitivity to stance limb angles was 84% higher than swing limb angles. The combined sensitivity to the sagittal plane angles was lower than the sensitivity to the frontal plane angles during unobstructed gait, and this relation was reversed during obstacle crossing. The results highlight the importance of the stance limb joints and indicate that frontal plane angles should not be ignored.
Jonathan S. Dufour, Alexander M. Aurand, Eric B. Weston, Christopher N. Haritos, Reid A. Souchereau, and William S. Marras
The objective of this study was to test the feasibility of using a pair of wearable inertial measurement unit (IMU) sensors to accurately capture dynamic joint motion data during simulated occupational conditions. Eleven subjects (5 males and 6 females) performed repetitive neck, low-back, and shoulder motions simulating low- and high-difficulty occupational tasks in a laboratory setting. Kinematics for each of the 3 joints were measured via IMU sensors in addition to a “gold standard” passive marker optical motion capture system. The IMU accuracy was benchmarked relative to the optical motion capture system, and IMU sensitivity to low- and high-difficulty tasks was evaluated. The accuracy of the IMU sensors was found to be very good on average, but significant positional drift was observed in some trials. In addition, IMU measurements were shown to be sensitive to differences in task difficulty in all 3 joints (P < .05). These results demonstrate the feasibility for using wearable IMU sensors to capture kinematic exposures as potential indicators of occupational injury risk. Velocities and accelerations demonstrate the most potential for developing risk metrics since they are sensitive to task difficulty and less sensitive to drift than rotational position measurements.
Jessa M. Buchman-Pearle, David C. Kingston, and Stacey M. Acker
Movement pattern differences may contribute to differential injury or disease prevalence between individuals. The purpose of this study was to identify lower limb movement patterns in high knee flexion, a risk factor for knee osteoarthritis, and to investigate kinematic differences between males and females, as females typically develop knee osteoarthritis more commonly and severely than males. Lower extremity kinematic data were recorded from 110 participants completing 4 variations of squatting and kneeling. Principal component analysis was used to identify principal movements associated with the largest variability in the sample. Across the tasks, similar principal movements emerged at maximal flexion and during transitions. At maximal flexion, females achieved greater knee flexion, facilitated by a wider base of support, which may alter posterior and lateral tibiofemoral stress. Principal movements also detected differences in movement temporality between males and females. When these temporal differences occur due to alterations in movement velocity and/or acceleration, they may elicit changes in muscle activation and knee joint stress. Movement variability identified in the current study provides a framework for potential modifiable factors in high knee flexion, such as foot position, and suggests that kinematic differences between the sexes may contribute to differences in knee osteoarthritis progression.
Alesha Reed, Jacqueline Cummine, Neesha Bhat, Shivraj Jhala, Reyhaneh Bakhtiari, and Carol A. Boliek
Purpose: The authors evaluated changes in intermuscular coherence (IMC) of orofacial and speech breathing muscles across phase of speech production in healthy younger and older adults. Method: Sixty adults (30 younger = M: 26.97 year; 30 older = M: 66.37 year) read aloud a list of 40 words. IMC was evaluated across phase: preparation (300 ms before speech onset), initiation (300 ms after onset), and total execution (entire word). Results: Orofacial IMC was lowest in the initiation, higher in preparation, and highest for the total execution phase. Chest wall IMC was lowest for the preparation and initiation and highest for the total execution phase. Despite age-related differences in accuracy, neuromuscular modulation for phase was similar between groups. Conclusion: These results expand our knowledge of speech motor control by demonstrating that IMC is sensitive to phase of speech planning and production.