The Effect of Two Types of Thoracolumbosacral Braces on Electromyography Activity of Selected Muscles in Patients with Kyphosis during Walking

Introduction: The relationship between the use of braces and gait parameters in people with kyphosis has been not well understood. The aim of the present study was to evaluate the effect of two types of thoracolumbosacral braces on erector spinae, and gluteus medius muscles activities in individuals with kyphosis during walking. Materials and Methods: Fifteen males with kyphosis volunteered to participate in the present study. All participants were right footed. Each participant performed three walking trials in each of the three brace conditions including without brace, with alarm brace, and with simple brace. Muscle activities were recorded during walking at constant walk speed. Statistical analysis was performed using repeated measures ANOVA test at the significant level of 0.05. All analyses were performed using the SPSS version 22. Results: There is no significant difference in electromyography activities of the lower limb muscles at the loading response and mid-stance phases (P>0.05). Also, results showed a significant difference during push-off phase for gastrocnemius medialis muscle (P<0.05). Conclusions: The use of thoracolumbosacral braces reduced the electrical activity of the gastrocnemius medialis muscle during the push-off phase. These changes may lead to gait efficiency while using thoracolumbosacral braces

Effects of Running on Sand vs. Stable Ground on Kinetics and Muscle Activities in Individuals With Over-Pronated Feet

Background: In terms of physiological and biomechanical characteristics, over-pronation of the feet has been associated with distinct muscle recruitment patterns and ground reaction forces during running. Objective: The aim of this study was to evaluate the effects of running on sand vs. stable ground on ground-reaction-forces (GRFs) and electromyographic (EMG) activity of lower limb muscles in individuals with over-pronated feet (OPF) compared with healthy controls. Methods: Thirty-three OPF individuals and 33 controls ran at preferred speed and in randomized-order over level-ground and sand. A force-plate was embedded in an 18-m runway to collect GRFs. Muscle activities were recorded using an EMG-system. Data were adjusted for surface-related differences in running speed. Results: Running on sand resulted in lower speed compared with stable ground running (p < 0.001; d = 0.83). Results demonstrated that running on sand produced higher tibialis anterior activity (p = 0.024; d = 0.28). Also, findings indicated larger loading rates (p = 0.004; d = 0.72) and greater vastus medialis (p < 0.001; d = 0.89) and rectus femoris (p = 0.001; d = 0.61) activities in OPF individuals. Controls but not OPF showed significantly lower gluteus-medius activity (p = 0.022; d = 0.63) when running on sand. Conclusion: Running on sand resulted in lower running speed and higher tibialis anterior activity during the loading phase. This may indicate alterations in neuromuscular demands in the distal part of the lower limbs when running on sand. In OPF individuals, higher loading rates together with greater quadriceps activity may constitute a proximal compensatory mechanism for distal surface instability

Corrigendum to "Quantifying lower limb inter-joint coordination and coordination variability after four-month wearing arch support foot orthoses in children with flexible flat feet" [Human Movement Science 70 (2020) 102593]

The authors regret: The first line under section 2.4 Calculation of coordination and coordination variability should read: • ‘The following equations are based on the step by step approach devised and reported by Needham et al. (2014)’. • Cite Chang et al. (2008) in addition to Sparrow et al. (1987) for equation, 4. Chang et al. (2008) already cited in paper. • Cite Batschelet (1981) in addition to Hamill et al., (2000). Batschelet, E., 1981. Circular Statistics in Biology. Academic Press, New York. The authors would like to apologise for any inconvenience caused.</p

Quantifying lower limb inter-joint coordination and coordination variability after four-month wearing arch support foot orthoses in children with flexible flat feet

Introduction: Flat feet in children negatively affect lower limb alignment and cause adverse health-related problems. The long-term application of foot orthoses (FOs) may have the potential to improve lower limb coordination and its variability. Aim: To evaluate the effects of long-term use of arch support FOs on inter-joint coordination and coordination variability in children with flexible flat feet. Methods: Thirty boys with flexible flat feet were randomly assigned to the experimental (EG) and control groups. The EG used medial arch support FOs during daily activities over a four-month period while the control group received a flat 2-mm-thick insole for the same time period. Lower-limb coordination and variability during the 3 sub-stance phases were quantified using a vector coding technique. Results: Frontal plane ankle-hip coordination in EG during mid-stance changed to an anti-phase pattern (156.9) in the post-test compared to an in-phase (221.1) in the pre-test of EG and posttest of CG (222.7). Frontal plane knee-hip coordination in EG during loading response (LR) changed to an anti-phase pattern (116) in the post-test compared to an in-phase (35.5) in the pre-test of EG and post-test of CG (35.3). Ankle inversion/eversion-knee internal/external rotation joint coupling angle in EG changed to an in-phase pattern (59) in the post-test compared to a proximal phase (89) in the pre-test. Coupling angle variability increased in the post-test of EG for sagittal plane ankle-hip during push-off, transverse plane ankle-hip during LR and mid-stance, and transverse plane knee-hip during LR and mid-stance compared to pre-test of EG and post-test of CG. Conclusion: The long-term use of arch support FOs proved to be effective to alter lower limb coordination and coordination variability during walking in children with flexible flat feet. This new insight into coordinative function may be useful for improving corrective exercise strategies planned for children with flat feet

The Impact of COVID-19 and Muscle Fatigue on Cardiorespiratory Fitness and Running Kinetics in Female Recreational Runners

Background: There is evidence that fully recovered COVID-19 patients usually resume physical exercise, but do not perform at the same intensity level performed prior to infection. The aim of this study was to evaluate the impact of COVID-19 infection and recovery as well as muscle fatigue on cardiorespiratory fitness and running biomechanics in female recreational runners. Methods: Twenty-eight females were divided into a group of hospitalized and recovered COVID-19 patients (COV, n = 14, at least 14 days following recovery) and a group of healthy age-matched controls (CTR, n = 14). Ground reaction forces from stepping on a force plate while barefoot overground running at 3.3 m/s was measured before and after a fatiguing protocol. The fatigue protocol consisted of incrementally increasing running speed until reaching a score of 13 on the 6–20 Borg scale, followed by steady-state running until exhaustion. The effects of group and fatigue were assessed for steady-state running duration, steady-state running speed, ground contact time, vertical instantaneous loading rate and peak propulsion force. Results: COV runners completed only 56% of the running time achieved by the CTR (p < 0.0001), and at a 26% slower steady-state running speed (p < 0.0001). There were fatigue-related reductions in loading rate (p = 0.004) without group differences. Increased ground contact time (p = 0.002) and reduced peak propulsion force (p = 0.005) were found for COV when compared to CTR. Conclusion: Our results suggest that female runners who recovered from COVID-19 showed compromised running endurance and altered running kinetics in the form of longer stance periods and weaker propulsion forces. More research is needed in this area using larger sample sizes to confirm our study findings

Effects of Core Stability Training on Kinematic and Kinetic Variables in Patients With Chronic Low Back Pain

Purpose: This study aims to assess the effects of an 8-week core stability training on the kinematics and kinetics of trunk flexion and extension motions in patients with chronic non-specific low back pain (CNSLBP).  Methods: A total of 30 CNSLBP patients with the age range of 25 to 45 years were randomly divided into 2 equally sized groups. The subjects were identified through clinical examination. Before and after the training, tests were applied to assess peak 3-dimensional hip joint moments, peak negative and positive hip joint powers, and lumbopelvic coupling angles during trunk flexion and extension motions. The first group underwent an 8-week core stability training program, including the specific exercise of the deep muscles of abdominal along with the lumbar multifidus co-activation. After the 8-week program, the post-test stage was performed similarly to the pre-test. Results: The main effects of “time” (P=0.029, f=0.84) and “time-by-group” interactions (P=0.03, f=0.16) for hip abductor moments and internal rotator moment (P=0.03, f=0.87) were significant. A trend toward the statistically significant main effect of “time” was found for the coupling angle during the flexion phase (P<0.05, f=1.88), extension phase (P=0.02, f=0.93), and “time×group” interaction during the flexion (P<0.05, f=1.96), extension (P=0.01, f=0.96) phases.  Conclusion: Core stability training has the potential to improve kinematics and kinetics during trunk flexion and extension motions in patients with CNSLBP.  <div class="msocomtxt" id="_com_2" language="JavaScript" onmouseout="msoCommentHide('_com_2')" onmouseover="msoCommentShow('_anchor_2','_com_2')"

Eight Weeks of Exercising on Sand Has Positive Effects on Biomechanics of Walking and Muscle Activities in Individuals with Pronated Feet: A Randomized Double-Blinded Controlled Trial

This study aimed to investigate the effects of eight weeks of barefoot running exercise on sand versus control on measures of walking kinetics and muscle activities in individuals with diagnosed pronated feet. Sixty physically active male adults with pronated feet were randomly allocated into an intervention or a waiting control group. The intervention group conducted an 8-weeks progressive barefoot running exercise program on sand (e.g., short sprints) with three weekly sessions. Pre and post intervention, participants walked at a constant speed of 1.3 m/s &plusmn; 5% on a 18 m walkway with a force plate embedded in the middle of the walkway. Results showed significant group-by-time interactions for peak impact vertical and lateral ground reaction forces. Training but not control resulted in significantly lower peak impact vertical and lateral ground reaction forces. Significant group-by-time interactions were observed for vastus lateralis activity during the loading phase. Training-induced increases were found for the vastus lateralis in the intervention but not in the control group. This study revealed that the applied exercise program is a suitable means to absorb ground reaction forces (e.g., lower impact vertical and lateral peaks) and increase activities of selected lower limb muscles (e.g., vastus lateralis) when walking on stable ground

The Effect of Ratio of Contraction to Relaxation Durations in PNF Exercises on the Muscle Strength and Range of Motion of Hip Joint

Objective: The aim of the present study was to compare the effect of ratios of contraction- Relaxation on the muscle strength and range of motion of hip joint in PNF exercises. Methods: Thirty nine nonathletic male students (Mean±SD; age, 13±1.2 years; body mass, 55±9.8 kg) were assigned .Three groups designated as I, II and III groups. The ratios of contraction to relaxation periods for groups were 1, 2 and 3 respectively. Training program included three sessions per week (CR-PNF) for 6 weeks. Measurements of hip extensors muscles stretch and strength were performed at the beginning and at the end of training using an inclinometer (during leg raise test) and dynamometer. Data were analyzed using dependent samples t-test and one-way ANOVA. Results: The results of the present study showed significant increases in hip extensor muscles flexibility and strength for three groups. This increase the in the strength in group I equaled 6 kg, in group II 4 kg and in group III 7 kg. The amount of increase in the hip extensor muscles flexibility in group I, II and II were 15, 8 and 12 degrees, respectively. The increase in these two variables was significant and similar in all three groups. Conclusion: Different contraction to relaxation ratio normally, 0.5, 1 and 2, did not show any meaningful differences on hip extensor muscular strength and hip range of motion

The Immediate Effects of Arch Support Insole on Ground Reaction Forces during Walking

Introduction: Evaluation of ground reaction forces (GRF) and other kinetic parameters have clinical importance. These parameters may cover all possible interaction between shoe type and insole. This study aimed to investigate the immediate effects of arch support insole on GRF and their peak time, impulse, loading rate, and free moment during stance phase of gait in normal individuals. Materials and Methods: Sixteen healthy male subjects with mean ± SD age; 29.4 ± 4.8 years, mean ± SD mass; 77.9 ± 12.6 kg and mean ±SD height; 176.5 ± 5.8 cm were participated in this study. All parameters were measured using two adjacent Kistler force plates (1000Hz) during stance phase of walking in two different conditions: with and without shoe insole. Maximum GRF and their related peak time, impulse, loading rate, and free moment were recorded. Repeated measure ANOVA was used to analyze the data (α = 0.05). Results: Wearing insole caused reduction the peak vertical GRF (PvGRF) in heel contact phase by 6.9% of body weight (BW) (P = 0.001) and the loading rate (8.4%, P = 0.02). However, it increased the propulsive force (7% N/BW, P = 0.001), anterior-posterior impulse by 1.2% BW (P = 0.003) and normal impulse by 2% of BW (P = 0.032)

The Effects of Foot Orthoses and Shoes on the Biomechanics of the Lower Limbs and Balance in Individuals with Pronated Feet: A Review Study

Foot pronation, as one of the prevalent foot abnormalities, can influence the biomechanics of the lower limbs. The use of various foot orthoses, including insoles and braces, is very common in eliminating this problem. The results obtained regarding the effect of orthoses on pain and biomechanics of individuals with foot pronation are different. The present review study was conducted to evaluate the effects of foot orthoses and shoes on the biomechanics of the lower limbs and balance in individuals with foot pronation. The articles were searched in Persian and Latin languages during 2004-22 in the databases of PubMed, Web of Science (WOS), Scopus, Islamic Science Citation (ISC), and Google Scholar search engine. Moreover, the types of the searched studies were original research, review studies, and clinical trials. Using keywords of Foot pronation, Foot orthoses, Medical soles, and Motion-control shoes, 52 relevant articles were selected, and 22 articles regarding the effects of orthoses and shoes on foot pronation were finally analyzed. Eight articles also reported that reducing forces imposed on the joints, absorbing shock, preventing pronation-related running injuries, and improving muscle activity occurred when using orthosis. Furthermore, 4 articles reported improving sports performance in athletes, reducing the ground reaction forces, and changing the frequency of muscle activity. Finally, 2 articles showed that motion-control shoes prevented intensifying the injury due to increased fatigue and subsequently increased mechanical loading during running. The results of the present study demonstrated that foot orthoses and motion-control shoes could have positive effects on balance, improving the activities of the lower limbs and reducing foot pronation and force imposed on the foot and lower limb joints