The Impact of Excessive Body Weight and Foot Pronation on Running Kinetics: A Cross-Sectional Study.

BACKGROUND: Running exercise is an effective means to enhance cardiorespiratory fitness and body composition. Besides these health benefits, running is also associated with musculoskeletal injuries that can be more prevalent in individuals with excessive body weight. Little is known regarding the specific effects of overweight and foot pronation on ground reaction force distribution during running. Therefore, this study aimed to investigate the effects of overweight/obesity and foot pronation on running kinetics. METHODS: Eighty-four young adults were allocated to four experimental groups: non-excessive body weight/non-pronated feet; non-excessive body weight/pronated feet; overweight or obesity/ non-pronated feet and overweight or obesity/pronated feet. Biomechanical testing included participants to run at ~ 3.2 m/s over an 18-m walkway with an embedded force plate at its midpoint. Three-dimensional ground reaction forces were recorded and normalized to body mass to evaluate running kinetics from 20 running trials. Test-re-test reliability for running speed data demonstrated ICC > 0.94 for each group and in total. RESULTS: The results indicated significantly lower vertical impact peak forces (p = 0.001, effect size = 0.12), shorter time to reach the vertical impact peak (p = 0.006, effect size = 0.08) and reduced vertical loading rate (p = 0.0007, effect size = 0.13) in individuals with excessive body weight (overweight or obesity/non-pronated feet group and overweight or obesity/pronated feet) compared with individuals non-excessive body weight (non-excessive body weight/non-pronated feet and non-excessive body weight/pronated feet). Moreover, the excessive body weight groups presented lower peak braking (p = 0.01, effect size = 0.06) and propulsion forces (p = 0.003, effect size = 0.09), lower medio-lateral loading rate (p = 0.0009, effect size = 0.12), and greater free moments (p = 0.01, effect size = 0.07) when compared to the non-overweight groups. Moreover, a significant body mass by foot pronation interaction was found for peak medio-lateral loading rate. Non-excessive body weight/pronated feet, excessive body weight/non-pronated feet and excessive body weight/pronation groups presented lower medio-lateral loading rates compared to non-excessive body weight/non-pronated feet (p = 0.0001, effect size = 0.13). CONCLUSIONS: Our results suggest that excessive body weight has an impact on ground reaction forces during running. We particularly noted an increase in medio-lateral and torsional forces during the stance phase. Individuals with excessive body weight appear to adapt their running patterns in an effort to attenuate early vertical impact loading.

The effects of cognitive intervention on inter-joint coordination during walking in the older adults with balance impairment.

BACKGROUND: Cognitive interventions are among the effective training-on-gait parameters; however, the effects of such trainings on inter-joints coordination has not been much considered. RESEARCH QUESTION: Can dual task and executive function training affect inter-joint coordination during walking in elderly with poor balance? METHODS: Thirty elderly men were purposefully divided into three groups: 1) dual-task training group (DTG), 2) executive function training group (EFG) and 3) control group. After the pre-test, the experimental groups participated in 24 training sessions while the control group were required to do their normal daily tasks. VICON three-dimensional motion analysis system with four T20 series cameras was used to evaluate inter-joints coordination during the experiment. Participants had to walk a 12-meter path while kinematics of their joints was recorded. The inter-joint coordination at the sagittal plane and in four phases were assessed using the vector coding technique. RESULTS: The findings of this study showed that the greatest effect of the intervention on the coordination between the joints was in the loading and mid-stance phases (p < 0.05). Also, the variability in the coupling angle showed a significant decrease in most phases (p < 0.05). SIGNIFICANCE: Based on the obtained results, it can be argued that the loading and mid-stance are more involved in postural control and balance because the center of gravity is transferred between the legs and the person is normally on single-leg stance in these phases.

Effects of an 8-week multimodal exercise program on ground reaction forces and plantar pressure during walking in boys with autism spectrum disorder.

BACKGROUND: Autism spectrum disorder is a developmental disability with first signs appearing in children aged 3 years and younger. Given that autism spectrum disorder is accompanied by a broad range of symptoms such as impaired sensory, neurological, and neuromotor functions, it appears plausible to argue that an intervention program focusing on multimodal exercise rather than single-mode exercise might be more effective in treating this wide variety of symptoms. OBJECTIVE: The aim of this study was to evaluate the effects of a multimodal exercise program entitled Sports, Play, and Active Recreation for Kids on variables of ground reaction forces and plantar pressure during walking in boys with autism spectrum disorder. METHODS: Twenty-four autism spectrum disorder boys aged 7-11 years were recruited and randomly allocated into an intervention or a waiting control group. Sports, Play, and Active Recreation for Kids was conducted over a period of 8 weeks with three weekly sessions. This training protocol includes aerobic dance and jump rope exercises as well as running games. Pre- and post-training, ground reaction forces and plantar pressure variables were recorded while walking at a constant walking speed of 0.9 m/s using a foot scan embedded in a 15-m walkway. RESULTS: Significant group-by-time interactions were found for the first peak of vertical ground reaction force, loading rate, and peak pressure at the medial heel region (all p = 0.001-0.49, d = 0.89-1.40). Post-hoc analyses showed significant pre-post decreases for the first peak of vertical ground reaction force (p = 0.001, d = 1.27), loading rate (p = 0.009, d = 1.11), and peak pressure at the medial heel region (p = 0.021, d = 1.01). CONCLUSIONS: Our results suggest that a joyful and multimodal exercise program has positive effects on kinetic walking characteristics of autism spectrum disorder boys. Accordingly, we recommend to implement this type of exercise in prepubertal autism spectrum disorder boys to improve gait kinetics. TRIAL REGISTRATION: Iranian Registry of Clinical Trials IRCT20170806035517N4. Registered on November 8, 2021. This study was approved by the Ethical Committee of the University of Mohaghegh Ardabili, Ardabil, Iran (IR.UMA.REC.1400.019). The study was conducted in accordance with the latest version of the Declaration of Helsinki.

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.

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 ± 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.

Recreational runners who recovered from COVID-19 show different running kinetics and muscle activities compared with healthy controls.

BACKGROUND: Social isolation through quarantine represents an effective means to prevent COVID-19 infection. A negative side-effect of quarantine is low physical activity. RESEARCH QUESTION: What are the differences of running kinetics and muscle activities of recreational runners with a history of COVID-19 versus healthy controls? METHODS: Forty men and women aged 20-30 years participated in this study and were divided into two experimental groups. Group 1 (age: 24.1 ± 2.9) consisted of participants with a history of COVID-19 (COVID group) and group 2 (age: 24.2 ± 2.7) of healthy age and sex-matched controls (controls). Both groups were tested for their running kinetics using a force plate and electromyographic activities (i.e., tibialis anterior [TA], gastrocnemius medialis [Gas-M], biceps femoris [BF], semitendinosus [ST], vastus lateralis [VL], vastus medialis [VM], rectus femoris [RF], gluteus medius [Glut-M]). RESULTS: Results demonstrated higher peak vertical (p = 0.029; d=0.788) and medial (p = 0.004; d=1.119) ground reaction forces (GRFs) during push-off in COVID individuals compared with controls. Moreover, higher peak lateral GRFs were found during heel contact (p = 0.001; d=1.536) in the COVID group. COVID-19 individuals showed a shorter time-to-reach the peak vertical (p = 0.001; d=3.779) and posterior GRFs (p = 0.005; d=1.099) during heel contact. Moreover, the COVID group showed higher Gas-M (p = 0.007; d=1.109) and lower VM activity (p = 0.026; d=0.811) at heel contact. SIGNIFICANCE: Different running kinetics and muscle activities were found in COVID-19 individuals versus healthy controls. Therefore, practitioners and therapists are advised to implement balance and/or strength training to improve lower limbs alignment and mediolateral control during dynamic movements in runners who recovered from COVID-19.

Effect of textured foot orthoses on walking plantar pressure variables in children with autism spectrum disorders.

The aim of this study was to evaluate the effect of textured foot orthoses on plantar pressure variables in children with autism spectrum disorders (ASDs). Thirty boys were divided into two groups based on their health status, namely: autism spectrum disorder and healthy matched controls. Plantar pressure data were captured during stance phases of shod walking with and without textured foot orthoses. Remarkably larger peak force under the toe1 and metatarsal1 and peak pressure under the toe1 and toe2-5 regions were observed in the autism group comparing with the healthy group, while lower peak force under the toe1, metatarsal1 and metatarsal2 were seen during walking with textured foot orthoses comparing with the cases of walking without them. The results showed higher values of peak pressure under metatarsal3, metatarsal4 and metatarsal5 for the textured foot orthoses walking against the cases without them. Also, analysis depicted huge reductions from pre-to-posttest for the peak pressure under toe2-5 only cases within the autism group. The reason of observing higher peak values of forces and pressures within their forefoot can potentially be their tendency to walk on their toes comparing against the healthy control children. This causes lower pressure values within all toes and the first metatarsal regions during normal walking with textured foot orthoses than walking without them. The findings revealed that the use of textured foot orthoses reduced peak pressure under toe2-5 only in the autism group. This suggests that the use of such interventions can help boys with ASDs move more safely.

Effects of nail softness and stiffness with distance running shoes on ground reaction forces and vertical loading rates in male elite long-distance runners with pronated feet.

BACKGROUND: To improve propulsion during running, athletes often wear spike shoes designed for training and/or competition. Running with spike shoes may cause pain and/or injuries. To address this problem, a modified spike shoe was tested. This study aimed to evaluate the effects of running with dual-versus single-stiffness spike running shoes on running mechanics in long-distance runners with pronated feet. METHODS: Sixteen male elite (national competitive level) runners (5000 or 10,000 m) aged 28.2 ± 2.5 years with pronated feet volunteered to participate in this study. To be included, participants had to have achieved personal best race times over 5- and/or 10-km races under 17 or 34 min during official running competitions. All participants were heel strikers and had a history of 11.2 ± 4.2 years of training. For the assessment of running kinetics, a force plate was imbedded into a walkway. Running kinematics were recorded using a Vicon-motion-capture system. Nike Zoom Rival shoes (Nike, Nike Zoom Rival, USA) were selected and adapted according to spike softness and stiffness. Participants ran at a constant speed of ~4.0 m/s across the walkway with both shoe conditions in randomized order. Six trials were recorded per condition. The main outcomes included peak ground reaction forces and their time-to-peak, average and instantaneous vertical loading rates, free moments, and peak ankle eversion angles. RESULTS: Paired t-tests revealed significantly lower lateral (p = 0.021, d = 0.95) and vertical (p = 0.010, d = 1.40) forces at heel contact during running with dual-stiffness spike shoes. Running with dual-stiffness spike shoes resulted in a significantly longer time-to-peak vertical (p = 0.004, d = 1.40) force at heel contact. The analysis revealed significantly lower average (p = 0.005, d = 0.46) and instantaneous (p = 0.021, d = 0.49) loading rates and peak negative free moment amplitudes (p = 0.016, d = 0.81) when running with dual-stiffness spike shoes. Finally, significantly lower peak ankle eversion angles were observed with dual-stiffness spike shoes (p < 0.001, d = 1.29). CONCLUSIONS: Running in dual- compared with single-stiffness spike distance running shoes resulted in lower loading rates, free moment amplitudes, and peak ankle eversion angles of long-distance runners with pronated feet.

Analysis of ground reaction forces and muscle activity in individuals with anterior cruciate ligament reconstruction during different running strike patterns.

BACKGROUND: Anterior cruciate ligament reconstruction provides successful clinical outcomes. However, reconstruction cannot restore normative lower limb mechanics during running. While numerous studies have investigated running characteristics in individuals with anterior cruciate ligament reconstruction, no study has been compared foot strike patterns among them. RESEARCH QUESTION: If ground reaction forces and lower extremity muscle activities in individuals with anterior cruciate ligament reconstruction and healthy control ones differ during three running strike patterns? METHODS: In this cross-sectional study, fourteen healthy adult males and fourteen adult males with anterior cruciate ligament reconstruction were recruited to participate. Surface electromyography of selected lower limb muscles and ground reaction forces were measured during three-strike patterns: rearfoot strike pattern, midfoot strike pattern, and forefoot strike pattern during barefoot running (∼ 3.3 m/s). RESULTS: The results revealed that the strike patterns influenced the peak lateral ground reaction force (P < 0.001) and peak vertical impact ground reaction force (P = 0.002) during the stance phase of running for both groups. The strike pattern also influenced the tibialis anterior (P < 0.001) and vastus lateralis (P = 0.035) activities during the early stance phase for both groups. However, the vastus medialis (P = 0.030) presented reduced activity, and the biceps femoris (P = 0.039) presented increased activity in the anterior cruciate ligament reconstruction group. Tibialis anterior (P = 0.021), gastrocnemius medialis (P < 0.001) and vastus medialis (P < 0.001) presented lesser activity irrespective of strike patterns in the anterior cruciate ligament reconstruction group. SIGNIFICANCE: Running with a forefoot strike pattern may be associated with lesser rearfoot eversion due to lower peak lateral ground reaction forces than running with a rearfoot strike pattern or midfoot strike pattern. Moreover, the altered muscle activities could contribute to the elevated risk of future joint injury in the anterior cruciate ligament reconstruction population.

Long-term effects of shoe mileage on knee and ankle joints muscle co-contraction during walking in females with genu varus.

BACKGROUND: Shoe mileage may influence the risk of sustaining injuries during walking. RESEARCH QUESTION: What are the effects of shoe mileage on knee and ankle muscle co-contraction during walking in females with genu varus? METHODS: Fifteen healthy and 15 women diagnosed with genu varus received a new pair of running shoes. They were asked to wear these shoes over 6 months. Pre and post intervention, muscle activities of the dominant limb were recorded during a walking test at preferred gait speed. Two dependent variables were assessed to examine muscle co-contraction: (1) directed co-contraction ratios of agonists and antagonists, and (2) general joint muscle co-contraction. FINDINGS: Results demonstrated significant main effects of the "shoe" factor for general ankle co-contraction during the push-off phase (p = 0.013, d = 1.503). Irrespective of experimental group, paired comparisons revealed significantly lower general ankle co-contraction during the push-off phase after the intervention. A significant main effects of "shoe" for general knee co-contraction during loading phase (p = 0.025, d = 0.895) was also observed. In both groups, paired comparison revealed significantly lower general knee co-contraction during the push-off phase in the post condition. We did not find any significant main effect of group nor group-by-shoe interaction for general ankle co-contraction during the stance phase. Likewise, we did not observe any significant main effect of "shoe", "group" and "group-by-shoe" interaction for mediolateral directed knee co-contraction during stance phase of walking (p > 0.05). SIGNIFICANCE: Our findings showed that the shoe mileage but not the genu varus condition affects the general and directed co-contraction of the muscles stabilizing the knee and ankle joints. Together with the observed findings on ankle and knee muscle co-contraction, it is essential to change running shoes after a long wearing time in both healthy and genu varus females.

The impact of hearing loss on three-dimensional lower limb joint torques during walking in prepubertal boys.

INTRODUCTION: In children, the impact of hearing loss on biomechanical gait parameters is not well understood. Thus, the objectives of this study were to examine three-dimensional lower limb joint torques in deaf compared to age-matched healthy (hearing) children while walking at preferred gait speed. METHODS: Thirty prepubertal boys aged 8-14 were enrolled in this study and divided into a group with hearing loss (deaf group) and an age-matched healthy control. Three-dimensional joint torques were analyzed during barefoot walking at preferred speed using Kistler force plates and a Vicon motion capture system. RESULTS: Findings revealed that boys with hearing loss showed lower joint torques in ankle evertors, knee flexors, abductors and internal rotators as well as in hip internal rotators in both, the dominant and non-dominant lower limbs (all p < 0.05; d = 1.23-7.00; 14-79%). Further, in the dominant limb, larger peak ankle dorsiflexor (p < 0.001; d = 1.83; 129%), knee adductor (p < 0.001; d = 3.20; 800%), and hip adductor torques (p < 0.001; d = 2.62; 350%) were found in deaf participants compared with controls. CONCLUSION: The observed altered lower limb torques during walking are indicative of unstable gait in children with hearing loss. More research is needed to elucidate whether physical training (e.g., balance and/or gait training) has the potential to improve walking performance in this patient group.

Long-term effects of shoe mileage on ground reaction forces and lower limb muscle activities during walking in individuals with genu varus.

BACKGROUND: Shoe mileage is an important factor that may influence the risk of sustaining injuries during walking. The aims of this study were to examine the effects of shoe mileage on ground reaction forces and activity of lower limb muscles during walking in genu varus individuals compared with controls. METHODS: Fifteen healthy and 15 genu varus females received a new pair of running shoes. They were asked to wear these shoes over 6 months. Pre and post intervention, mechanical shoe testing was conducted and ground reaction forces and muscle activities of the right leg were recorded during walking at preferred gait speed. FINDINGS: Significant group-by-time interactions were found for shoe stiffness, antero-posterior and vertical impact peak. We observed higher shoe stiffness and lower impact peaks after intervention in both groups with larger effect sizes in genu varus. Significant group-by-time interactions were identified for vastus medialis (loading phase) and rectus femoris (loading and push-off). For vastus medialis, significant decreases were found from pre-to-post during the loading phase in the control group. Rectus femoris activity was higher post intervention during the loading and push-off phases in both groups with larger effect sizes in genu varus. INTERPRETATION: Our findings indicate that the observed changes in ground reaction forces are more prominent in genu varus individuals. Together with our findings on shoe stiffness, it seems appropriate to change running shoes after an intense wearing time of 6 months, particularly in genu varus individuals.

Effect of a corrective exercise program on gait kinetics and muscle activities in older adults with both low back pain and pronated feet: A double-blind, randomized controlled trial.

BACKGROUND: Low back pain is among the most common health problems seen in primary care. This study aimed to evaluate the effect of a corrective exercise program on GRF components, back pain, disability score, and muscle activities in back pain patients with pronated feet during walking. RESEARCH QUESTION: What is the effect of corrective exercise program on gait kinetics, back pain, disability score, and muscle activities in back pain patients with pronated feet during walking? METHODS: Thirty-six older adults with both back pain and pronated feet volunteered to participate in this study. They were randomly divided into two equal groups (experimental and control groups). Kinetic and EMG data were recorded during both pre and posttest. Visual analog pain scale and Roland-Morris disability questionnaire were used to assess back pain and disability values, respectively. RESULTS: In the experimental group but not in the control group, walking speed was significantly increased from pre to posttest (p = 0.001). The loading rate and free moment values were similar during both the pre and posttest (p > 0.05). In the experimental group but not in the control group, the disability score, back pain, tibialis anterior activity, and rectus abdominis activity were decreased during the posttest than that in the pretest (p < 0.001). SIGNIFICANCE: Higher walking speed, lower muscle activity and pain, lower disability score along with similar loading rate and free moments in the experimental group compared with the control group after the training protocol demonstrate the improvement of gait efficiency.

Motion-control shoes help maintaining low loading rate levels during fatiguing running in pronated female runners.

BACKGROUND: The use of motion-control shoes may assist pronated runners to maintain their stability throughout a fatiguing running. However, there are no studies describing the effects of fatigue on running biomechanics of runners with pronated feet. RESEARCH QUESTION: Whether motion-control shoes can assist pronated recreational female runners to maintain impact loading patterns following a fatiguing protocol? METHODS: Twenty-two female rearfoot runners with foot pronation were asked to perform a fatiguing treadmill running protocol using a neutral shoe or a motion-control shoe in two separate occasions. Before (Pre-fatigue) and after the fatiguing protocol (Post-fatigue), participants were asked to run overground on a track that contained two force platforms to record ground reaction forces and moments. Running speed were 3.3 m s-1 (±2.5% variability). The effects of shoe type and fatigue were investigated on the peak vertical impact ground reaction force (pvIGRF), time to reach pvIGRF, vertical loading rate (LR) and peak negative foot free moments (FM). RESULTS: Pronated runners presented lower LR with motion-control shoes compared to neutral shoes Pre- (p < 0.005; -18 ±â€¯25%) and Post-fatigue (p < 0.001; -27 ±â€¯15%). This change in LR was predominantly driven by a longer time to reach pvIGRF with motion-control shoes (p < 0.001, 39%). The pvIGRF and LR increased after fatiguing running with neutral shoes (pvIGRF: p < 0.05; 18 ±â€¯28%; LR: p < 0.05; 15 ±â€¯22%), but not with motion-control shoes. Furthermore, there were strong correlations between FM and LR for both Pre-fatigue (r=-0.61, p < 0.005) and Post-fatigue measurements (r=-0.66, p < 0.01), but only for the motion-control shoes. SIGNIFICANCE: These results suggest that motion-control shoes prevent exacerbated fatigue-related increases in mechanical loading following initial contact in pronated female runners.

The effect of working memory intervention on the gait patterns of the elderly.

INTRODUCTION: The purpose of this study was to evaluate the role of working memory (WM) training on walking patterns in elderly people. METHODS: 20 elderly adults were selected and assigned randomly to two groups: WM training group and control group. WM training group received 6 weeks of computerized training on various spatial and verbal WM tasks. The spatial-temporal parameters, the ground reaction force and the timing activity of muscles in pre-posttest and in a follow-up were taken. RESULT: The results indicated that a significant change in gait speed, double support time and stride time (p < 0.05). Alternations in ground reaction force (GRF) components were found significant. Timing of muscle activity also showed non-significant change after WM intervention. CONCLUSION: Based on the results of this study, it can be concluded that WM intervention can be applied to improve gait parameters. The improvements in vertical ground reaction force after training may result in an increase upright stability and a decreased in rate falls.

Sit-to-stand ground reaction force characteristics in blind and sighted female children.

BACKGROUND: The association between visual sensory and sit-to-stand ground reaction force characteristics is not clear. Impulse is the amount of force applied over a period of time. Also, free moment represents the vertical moment applied in the center of pressure (COP). RESEARCH QUESTION: How the ground reaction force components, vertical loading rate, impulses and free moment respond to long and short term restricted visual information? METHODS: Fifteen female children with congenital blindness and 45 healthy girls with no visual impairments participated in this study. The girls with congenital blindness were placed in one group and the 45 girls with no visual impairments were randomly divided into three groups of 15; eyes open, permanently eyes closed, and temporary eyes closed. The participants in the permanently eyes closed group closed their eyes for 20 min before the test, whereas temporary eyes closed group did tests with their eyes closed throughout, and those in the eyes open group kept their eyes open. RESULTS: Congenital blindness was associated with increased vertical loading rate, range of motion of knee and hip in the medio-lateral plane. Also, medio-lateral and vertical ground reaction force impulses. Similar peak negative and positive free moments were observed in three groups. SIGNIFICANCE: In conclusion, the results reveal that sit-to-stand ground reaction force components in blind children may have clinical importance for improvement of balance control of these individuals.

Rehabilitation improves walking kinematics in children with a knee varus: Randomized controlled trial.

BACKGROUND: Previous studies have demonstrated increased medial stresses in knee varus alignment. Selecting a suitable treatment strategy for individuals with knee malalignment should be a priority. OBJECTIVES: We aimed to investigate the effects of a 16-week corrective exercise continuum (CEC) program on 3-D joint angles of the dominant and non-dominant lower limbs in children with genu varus during walking. METHODS: Overall, 28 male children with genu varus (age range 9-14 years) volunteered to participate in this study. They were randomly divided into 2 equal groups (experimental and control). The participants of the experimental group received CEC for 16 weeks. 3-D gait analysis involved using a Vicon Motion System. Paired and independent sample t-tests were used for within- and between-group comparisons, respectively. RESULTS: For the experimental group, comparison of pre- and post-test joint kinematics of the dominant lower limb revealed that CEC decreased the peak ankle dorsiflexion angle by 26% (P=0.020), peak foot internal rotation angle by 53% (P=0.001), peak knee internal rotation angle by 40% (P=0.011), peak hip abduction by 47% (P=0.010), and peak hip external rotation angle by 60% (P=0.001). In contrast, peak knee external rotation angle of the dominant limb was increased after the training program by 46% (P=0.044). For the non-dominant lower limb, CEC decreased the peak ankle inversion by 63% (P<0.01), peak ankle eversion by 91% (P<0.01), peak foot internal rotation by 50% (P<0.01), peak knee internal rotation by 29%; P=0.042), peak hip abduction angle by 38% (P<0.01), and peak hip external rotation angle by 60% (P<0.01). CONCLUSIONS: CEC therapy reduced excessive foot and knee internal rotations as well as excessive hip external rotation during walking in children with genu varus.

Combining valgus knee brace and lateral foot wedges reduces external forces and moments in osteoarthritis patients.

Osteoarthritis progression can be related to the external knee adduction and flexion moments during walking. Lateral foot wedges and knee braces have been used as treatment for osteoarthritis, but little is known about their influence on knee joint moments generated in the sagittal and frontal planes. Therefore, the aim of the present study was determine the effects of the isolated and combined use of valgus knee brace and lateral wedge foot orthotic on peak forces and moments during gait in knee osteoarthritis patients. Twenty four males (age: 62.1±2.0years) with varus alignment, symptomatic medial compartment knee osteoarthritis participated in this study. Subjects walked over ground at preferred speed in four conditions: (1) no assistive device (control); (2) using lateral wedges, (3) using knee braces, and (4) using both lateral wedges and knee braces. Ground reaction forces (GRF) and moments, as well as lower limb kinematics were recorded. Peak GRF, vertical loading rate, free moment, external knee adduction and flexion moments were compared across conditions. The concurrent use of lateral wedge and knee brace reduced the first peak GRF in the vertical (6%, p=0.002), anterior-posterior (30%, p=0.028) and medial-lateral directions (44%, p=0.029). Moreover, the use of these devices reduced the peak external knee adduction moment (25%, p=0.019), but not the external flexion moment and free moment (p>0.05). The combined use of lateral wedges and knee braces can reduce medial-lateral knee joint loading, but despite reduced peak forces in the sagittal plane, these device do not reduce joint moments.

A comparison of running kinetics in children with and without genu varus: A cross sectional study.

INTRODUCTION: Varus knee alignment has been identified as a risk factor for the progression of medial knee osteoarthritis. However, the underlying mechanisms have not been elucidated yet in children. Thus, the aims of the present study were to examine differences in ground reaction forces, loading rate, impulses, and free moment values during running in children with and without genu varus. METHODS: Thirty-six boys aged 9-14 volunteered to participate in this study. They were divided in two age-matched groups (genu varus versus healthy controls). Body weight adjusted three dimensional kinetic data (Fx, Fy, Fz) were collected during running at preferred speed using two Kistler force plates for the dominant and non-dominant limb. RESULTS: Individuals with knee genu varus produced significantly higher (p = .01; d = 1.09; 95%) body weight adjusted ground reaction forces in the lateral direction (Fx) of the dominant limb compared to controls. On the non-dominant limb, genu varus patients showed significantly higher body weight adjusted ground reaction forces values in the lateral (p = .01; d = 1.08; 86%) and medial (p < .001; d = 1.55; 102%) directions (Fx). Further, genu varus patients demonstrated 55% and 36% greater body weight adjusted loading rates in the dominant (p < .001; d = 2.09) and non-dominant (p < .001; d = 1.02) leg, respectively. No significant between-group differences were observed for adjusted free moment values (p>.05). DISCUSSION: Higher mediolateral ground reaction forces and vertical loading rate amplitudes in boys with genu varus during running at preferred running speed may accelerate the development of progressive joint degeneration in terms of the age at knee osteoarthritis onset. Therefore, practitioners and therapists are advised to conduct balance and strength training programs to improve lower limb alignment and mediolateral control during dynamic movements.