Footwear\u27s Influence on Positional Parameters in the Static Posture of Children

In early childhood, a child’s motor control is rapidly evolving. Upright posture is being supported through a combination of sensory factors that are influenced by the child’s developing neuromuscular system.1 Footwear has the ability to create a drastic impact on postural stability during this key time in a child’s life. In fact, certain types of footwear may actually be detrimental to the child’s normal development of proprioceptive abilities, compared to being able to feel their natural environment while barefoot. Positional parameters of static posture can be used to evaluate the effects of footwear on postural control.2 PURPOSE: The purpose of this study was to investigate the effect that stiff soled shoes had on the posture of young children between the ages of 4 and 6 years old. METHODS: 13 healthy children between the ages of 4-6 participated in this study. There were 4 males and 9 females. The COP anteroposterior(AP), mediolateral(ML), and radiuses of static upright posture while barefoot and while wearing shoes were evaluated. RESULTS: There was a significant difference between the barefoot and shod conditions for COP AP means (Barefoot 4.57±1.14, Shod 4.44±1.11, p\u3c.05). There were no statistical differences for either COP ML means (Barefoot 15.48±9.14, Shod 11.208±6.836, p\u3e.05), or COP mean radiuses (Barefoot 16.771±8.085, Shod 12.802±5.632, p\u3e.05). CONCLUSION: In conclusion, it appears that the stiff soled shoes limit the position variables of static posture compared to standing barefoot, though our data was only significantly different for the AP direction. The data suggest that the stiff soled shoes are providing a constraint to the organization of the children’s posture, though there is not enough evidence to conclude there are negative effects to a child’s natural proprioception of their environment when shod with these specific shoes. Further investigation into the effects of footwear on posture in children, particularly the dynamics of posture, should be done

Difference of Elbow Extension Velocity During Flat and Mound Throwing

In baseball, players encounter varying forms of throwing that is dependent upon position. Pitchers often throw on a mound, while position players are seen throwing from a flat ground. The throwing motion of a baseball consists of six phases: wind-up, stride, late cocking, acceleration, deceleration, and follow through. Each of these different phases consists of velocities being produced from the lower body through the elbow, which contributes to a potential cause of throwing arm injuries. Given the prominence of elbow injuries to pitchers, investigation into the solution to reducing arm injuries has continued to gain traction. PURPOSE: The purpose of this study was to examine throwing kinematic velocities when throwing from flat ground compared to throwing from a mound. METHODS: Ten healthy individuals (20.2±1.23 years old) with previous pitching experience were recruited for this study. Subjects had 38 retro-reflective markers placed in various anatomical locations to quantify whole body kinematics during the throwing motion using a motion capture system. Subjects completed 10 total throws, five from flat ground, and five from a mound at a throwing distance of 30.5 meters. The five throws from each condition were then averaged. Peak pelvic rotation velocity, peak trunk rotation velocity, peak shoulder horizontal adduction velocity, and peak elbow extension velocity were calculated and analyzed with custom software. Dependent t-tests were ran to compare the flat ground and mound conditions for each dependent variable. RESULTS: There were no statistical differences for any of the dependent variables; peak pelvic rotation velocity (Flat 663.8m/s±80, Mound 586.7m/s±105, p\u3e.05), peak trunk rotation velocity (Flat 905.1m/s±108, Mound 878.2m/s±95, p\u3e.05), peak shoulder horizontal adduction velocity (Flat 1314.2m/s±288, Mound 1339.1m/s±265, p\u3e.05) or peak elbow extension velocity (Flat 2417.8m/s±473, Mound 2401.1m/s±453, p\u3e.05). CONCLUSION: In conclusion, we were unable to elucidate any differences in body kinematics when comparing flat ground to mound throwing. The implications of our study are that it is safe to throw from either the mound or flat ground, as the different throwing condition does not add any additional stress to the arm and the general kinematics of the throw are conserved. Future studies should aim to investigate other potential variables that may contribute to injury, particularly analyzing those variables during specific events during the phases of the throw

Relationship Between Regional Pectoralis Major Muscle Size and Peak Power During Incline Bench Press Strength Testing: A Pilot Study

The peak power generated by skeletal muscle during strength training is influenced by several factors, including body weight, maximal force, and muscle fiber orientation, as well as the function affecting excitation patterns. However, there is limited research on the relationship between regional muscle size and peak power output. PURPOSE: This pilot study seeks to explore the associations between muscle thickness (MT) and cross-sectional area (CSA) of the pectoralis major and peak power output during an incline bench (IB) press one-repetition maximum (1RM) strength bout. METHODS: Seven participants (males = 3; females = 4; age: 24.3±2.7 years; height: 168.2±3.3 cm; weight 68.71±4.86 kg;) had ultrasound measures completed of the pectoralis major at 10% and 25% of the distal to the supra sternal notch. Following this, participants performed 1RM strength tests on an IB press using a Smith machine set to 45 degrees. The barbell was fitted with a linear velocity transducer to measure bar displacement, bar velocity, and power output during the 1RM session. Ultrasound measures of MT and CSA were collected prior to the IB 1RM strength bout. Spearman’s rho (rs) correlations, and 95% confidence intervals, were performed to assess the relationship between MT and CSA measures and peak power output. RESULTS: The results indicated a strong, negative relationship between 25% MT of the pectoralis major and peak power output (rs=-0.71 [-0.957, 0.113]). However, there were weak, negative associations between peak power and CSA at both 10% (rs=-0.36 [-0.88, 0.56]) and 25% (rs=-0.21, [-0.84, 0.66]. Lastly, there was a negligible, negative relationship between peak power and 10% MT (rs=-0.07, [-0.79, 0.73]). CONCLUSION: These findings suggest that MT at 25% of the pectoralis major may be an important predictor of peak power output during IB 1RM strength testing. Further research is warranted to confirm whether muscle size can predict peak power during 1RM testing. Developing an algorithm or formula using CSA or MT as a predictor could be the next logical step, which would allow for a better understanding of the relationship between muscle characteristics and aid in developing more targeted training programs to optimize performance and reduce injury risk

Backpack Load and Unload Influence on Positional Parameters in the Static Posture of College Students

The investigation into the load carrying of military applications and children with a disability has been thoroughly evaluated. A population that has been largely ignored, though they are subjected to load carrying daily is the college student. College students often carry books and notebooks from class to class and can be subjected to substantial loads. PURPOSE: The purpose of this study was to investigate the effects of backpack load on positional parameters of static posture in college students. METHODS: Nineteen college-aged students (n = 19, Age = 21.4 ± 1.3 years, Height = 1.7 ± .1 m, Weight = 66.7 ± 10.4 kg) walked on an instrumented treadmill for 3 - 4 minutes followed by 1 minute of quiet standing while wearing an empty backpack and while wearing a backpack containing a 25lbs load. During the quiet standing trials, the center of pressure (COP) positional parameters (range, mean, root mean square (RMS)) of static posture were computed in both the anteroposterior (AP) and the mediolateral (ML) directions from COP force data. Data between the loaded and unloaded conditions was compared using a dependent t-test with an alpha of 0.05. RESULTS: There was a significant increase for the COP AP Range in the loaded ( M = .79 ± .31.) compared to the unloaded ( M = .41 ± .26 ) conditions ( p \u3c .05 ). There was also a significant increase for the COP ML Range in the loaded ( M + .16 ± .2 ) compared to the unloaded ( M = .05 ± .02) conditions ( p \u3c .05 ). There were no differences for the Mean and RMS for either the AP or ML directions ( p \u3e .05 ). CONCLUSION: Backpack load led to an increase in the positional parameter of postural control, AP and COP range. Backpack load did not have an effect on the mean or RMS of postural control. The increased backpack load caused the students to have greater excursions of their COP, however, this does not provide us with a clear understanding of what is happening to the postural control of the students. Further research into the effect of backpack load on the organization of the postural control and postural variability should be considered

Impact of Backpack Load and Unload on Dynamic Parameters of Static Posture

Backpacks are versatile and suitable tools in various educational settings, from elementary to university. Carrying a backpack can alter the natural walking gait. Individuals may adopt compensatory movements, such as leaning forward or to the side, to manage the load, affecting overall gait and balance. However, there has been little investigation into the changes in posture while carrying a backpack after walking. By incorporating dynamic movements, we can better understand how backpack use influences posture in real-world scenarios. PURPOSE: The purpose of this study is to investigate the influence of backpack load on dynamic parameters of static posture. METHODS: Nineteen college aged students (n = 19, Age = 21.4 ± 1.3 years, Height = 1.7 ± .1 m , Weight = 66.7 ± 10.4 kg) walked on an instrumented treadmill for 3 - 4 minutes followed by 1 minute of quiet standing while wearing an empty backpack and while wearing a backpack containing a 25lbs load. During the quiet standing trials, center of pressure (COP) velocity in both the anteroposterior (AP) and the mediolateral (ML) directions, and COP sway area rate was computed from COP force data. Data between the loaded and unloaded conditions was compared using a dependent t-test with an alpha of 0.05. RESULTS: There were no significant differences between the unloaded and loaded conditions for COP AP velocity, COP ML velocity, or sway area rate (p \u3e .05). CONCLUSION: Backpack load during quiet standing posture had no effect on the dynamic parameters of posture. It is possible that this method of analysis is not sensitive enough to detect the changes that load creates on the organization of posture. Future research into more sensitive methods, such as nonlinear analysis of the variability of posture should be investigated

Children\u27s Gait Kinematics Footwear Stiffness

At a young age, children are exceptionally plastic and can adapt well to changes in their environment. One particular environmental factor that is often overlooked is children’s footwear. Children are subjected to many different types of footwear at a prime age of development. Different types of footwear can have a range of stiffnesses, potentially influencing the way that children walk. PURPOSE: The purpose of this study was to investigate what effect varying footwear stiffnesses had on children’s gait kinematics. METHODS: Eleven healthy children between the ages of 4-6 participated in this study (Age = 4.8 ± .8 years, ht = 44.1 ± 3.8 in, wt = 47.1 ± 13.4 lbs). The children walked barefoot and in three separate footwear conditions (moccasin, minimalist, and rigid), on an instrumented treadmill for 3-minutes while motion capture data was captured. Gait kinematics, including range of motion (ROM) and peak joint angle velocities of the ankle, knee, and hip, were computed using Visual3D and custom Matlab software from the motion capture marker trajectories. A repeated measures ANOVA was used to determine any differences between the dependent variables for the conditions with LSD post hoc analysis conducted if necessary. (p = .05). RESULTS: There was a significant main effect for the knee flexion velocity, knee extension velocity, hip flexion velocity, and for hip extension velocity (p \u3e .05). Specifically for knee flexion velocity, the barefoot condition was significantly less than the minimalist and rigid shoe conditions (p \u3c .05) but not different from the moccasin. There was a gradual significant decrease by stiffness for the footwear conditions for knee extension velocity, with barefoot exhibiting the greatest velocity and rigid footwear having the least (p \u3c .05). Interestingly, there was the exact opposite effect for hip flexion velocity, with a steady increase from barefoot to rigid with the barefoot being significantly less than both the minimalist and rigid shoe conditions (p \u3c .05). Hip extension velocity was also significantly less in the barefoot condition compared to the rigid condition (p \u3c .05) though no other conditions were significantly different (p \u3e .05). CONCLUSION: Varying degrees of footwear stiffness had a substantial impact on children’s gait kinematics. Specifically, both the minimalist and rigid footwear conditions elicited the greatest differences compared to the barefoot conditions. However, there did not appear to be a difference between the moccasin and barefoot conditions. Future research should be conducted to further understand the potential negative impacts footwear has on the development of gait in children and if perhaps, shoes that truly mimic barefoot gait, such as moccasins, should be more regularly used

Static Stimuli\u27s Impact on Postural Linear Parameters in Children with Autism Spectrum Disorder

Limited or restricted forms of postural control has been reported in children diagnosed with Autism Spectrum Disorder (ASD) in contrast to their neurotypical counterparts. This aligns with the ASD inability to integrate sensory processing properly, thus producing a less adaptive postural response to changes in their environment. Interestingly, although there is a deficit in postural control, visual-spatial perception abilities in those with ASD tend to be advanced. For example, children with ASD have performed well in the block design subtest of the Weschler Intelligence Scale. Additionally, they tend to hyperfocus attention on one item while disregarding the others, another quality which may be advantageous in this research. PURPOSE: The purpose of this study was to investigate if a static stimulus, such as a target, will result in a stabilizing effect on posture, reducing postural sway and thereby causing alterations in postural control in children with ASD. METHODS: 6 children with ASD and 22 children with typical development had center of pressure (COP) data measured on the basis of two randomized visual conditions. One condition had a static target on a television placed at eye level of each participant, and the other condition was without a static target. During the trials, each child stood still for 3.5 minutes on a force plate, which recorded the COP anterior-posterior (AP) and medial-lateral (ML) data. RESULTS: Linear measures of mean, velocity, and root mean square (RMS) were calculated for each direction, utilizing a custom MatLab script. There were no statistical differences in COP AP and COP ML means, velocities, and RMSs for the ASD and neurotypical children (p\u3e0.05). CONCLUSION: Presentation of a static target stimulus did not seem to drastically alter the linear parameters of posture in ASD. No conclusion can be made as to how the visual target may alter and/or stabilize ASD posture based on this information. Linear measures of postural control may not be sensitive enough to detect differences among the ASD and neurotypical. Future investigations should focus on non-linear measures, which may be more sensitive to postural control differences

Spatiotemporal gait variability in children aged 2 to 10 decreases throughout pre-adolescence

Background: Children’s gait is traditionally understood to mature as young as three years old through pre-adolescence. Studies looking at gait biomechanics suggest that gait matures around three years old, while studies investigating gait variability propose a much later maturation. The studies that have examined children’s gait variability did so while the children walked around a track or down hallways that created a discontinuous gait, potentially affecting the measures of variability and the efficacy of the results. Purpose: Therefore, the purpose of our study was to investigate the development of gait dynamics and gait variability in children in a more continuous fashion, in this case, by walking on a treadmill. Methods: To accomplish this, we included four age groups of children, ranging 2–10 years old, walking on a treadmill for at least three minutes while stride time and stride length were collected. Stride time and stride length’s variability was then analyzed using linear (mean, standard deviation, coefficient of variation) and nonlinear (sample entropy, detrended fluctuation analysis) measures across the varying ages of our participants. Results: Interestingly, both the linear and nonlinear variabilities of the stride time and stride length measures decreased as the groups of children got older. Specifically, CV ST (2–3 (9.3 ± 4%), 8–10 (3.6 ± 0.7%), p < 0.05) and CV SL (2–3 (11.4 ± 3%), 8–10 (4.6 ± 1%), p < 0.05) were our strongest linear measures, and DFA α ST (2–3 (0.97 ± 0.12), 8–10 (0.82 ± 0.10), p < 0.05) and DFA α SL (2–3 (0.91 ± 0.04), 8–10 (0.81 ± 0.03), p < 0.05) were our strongest nonlinear measures, particularly between the youngest and oldest groups. This trend of variability decreasing with age suggests that as children’s gait matures, their gait becomes more stable and reliable. Significance: Our study rejects the notion that children’s gait is mature by the age of three, as some would suggest. By analyzing the variability of stride time and stride length, we can see that even later into childhood, children’s gait continues to change and evolve.This research received no external funding

The influence of distance on throwing kinematics in young health baseball players

Biomechanics Lab, KinesiologyDue to the high-intensity and repetitive nature of the throwing motion, baseball players are prone to arm injuries. There is a sudden rise in angular velocity through the kinematic chain as players increase their throwing distance. (Loftice, J., 2004) Long-toss routine is seen as a tool implemented in the hopes to reduce injury. (Fleisig G. et. al, 2011) This regimen consisted of players gradually increasing their throwing distance on both flat and a mound. Distinguishing whether a program can be advantageous or detrimental in its implementation is crucial