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 post-test 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.

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.

Effects of varus knee alignment on gait biomechanics and lower limb muscle activity in boys: A cross sectional study.

BACKGROUND: There is evidence that frontal plane lower limb malalignment (e.g., genu varus) is a risk factor for knee osteoarthritis development. However, only scarce information is available on gait biomechanics and muscle activity in boys with genu varus. RESEARCH QUESTION: To examine the effects of knee varus alignment on lower limb kinematics, kinetics and muscular activity during walking at self-selected speed in boys with genu varus versus healthy age-matched controls. METHODS: Thirty-six boys were enrolled in this study and divided into a group of boys with genu varus (n = 18; age: 11.66 ±â€¯1.64 years) and healthy controls (n = 18; age: 11.44 ±â€¯1.78 years). Three-dimensional kinematics, ground reaction forces, loading rates, impulses and free moments of both limbs were recorded during five walking trials at self-selected speed. Surface electromyography was recorded for rectus femoris and vastus lateralis/medialis muscles. RESULTS: No significant between-group differences were found for gait speed. Participants in the genu varus group versus controls showed larger peak knee flexion (p = 0.030; d = 0.77), peak knee adduction (p < 0.001; d = 1.63), and peak ankle eversion angles (p < 0.001; d = 2.06). Significantly higher peak ground reaction forces were found at heel contact (vertical [p = 0.002; d = 1.16] and posterior [p < 0.001; d = 1.63] components) and at push off (vertical [p = 0.010; d = 0.93] and anterior [p < 0.001; d = 1.34] components) for genu varus versus controls. Peak medial ground reaction force (p = 0.032; d = 0.76), vertical loading rate (p < 0.001; d = 1.52), anterior-posterior impulse (p = 0.011; d = 0.92), and peak negative free moment (p = 0.030; d = 0.77) were significantly higher in genu varus. Finally, time to reach peak forces was significantly shorter in genu varus boys compared with healthy controls (p < 0.01; d = 0.73-1.60). The genu varus group showed higher activities in vastus lateralis (p < 0.001; d = 1.82) and vastus medialis (p = 0.013; d = 0.90) during the loading phase of walking. SIGNIFICANCE: Our study revealed genu varus specific gait characteristics and muscle activities. Greater knee adduction angle in genu varus boys may increase the load on the medial compartment of the knee joint. The observed characteristics in lower limb biomechanics and muscle activity could play a role in the early development of knee osteoarthritis in genu varus boys.

Effects of Corrective Training on Drop Landing Ground Reaction Force Characteristics and Lower Limb Kinematics in Older Adults With Genu Valgus: A Randomized Controlled Trial.

The aim of this study was to identify the effects of a corrective exercise program on landing ground reaction force characteristics and lower limb kinematics in older adults with genu valgus. A total of 26 older male adults with genu valgus were randomized into two groups. An experimental group conducted a 14-week corrective exercise program, whereas a control group did not perform any exercise. The experimental group displayed lower peak vertical, peak anterior and posterior, and peak medial ground reaction force components during the posttest compared with the pretest. The vertical loading rate, impulses, and free moment amplitudes were not statistically different between groups. In the experimental group, the peak knee abduction during the posttest was significantly smaller and the peak hip flexion angle was significantly greater than during the pretest. The authors suggest that this corrective exercise program may be a suitable intervention to improve landing ground reaction forces and lower limb kinematics in older male adults with genu valgus.

The long-term use of foot orthoses affects walking kinematics and kinetics of children with flexible flat feet: A randomized controlled trial.

BACKGROUND: Due to inconclusive evidence on the effects of foot orthoses treatment on lower limb kinematics and kinetics in children, studies are needed that particularly evaluate the long-term use of foot orthoses on lower limb alignment during walking. Thus, the main objective of this study was to evaluate the effects of long-term treatment with arch support foot orthoses versus a sham condition on lower extremity kinematics and kinetics during walking in children with flexible flat feet. METHODS: Thirty boys aged 8-12 years with flexible flat feet participated in this study. While the experimental group (n = 15) used medial arch support foot orthoses during everyday activities over a period of four months, the control group (n = 15) received flat 2-mm-thick insoles (i.e., sham condition) for the same time period. Before and after the intervention period, walking kinematics and ground reaction forces were collected. RESULTS: Significant group by time interactions were observed during walking at preferred gait speed for maximum ankle eversion, maximum ankle internal rotation angle, minimum knee abduction angle, maximum knee abduction angle, maximum knee external rotation angle, maximum knee internal rotation angle, maximum hip extension angle, and maximum hip external rotation angle in favor of the foot orthoses group. In addition, statistically significant group by time interactions were detected for maximum posterior, and vertical ground reaction forces in favor of the foot orthoses group. CONCLUSIONS: The long-term use of arch support foot orthoses proved to be feasible and effective in boys with flexible flat feet to improve lower limb alignment during walking.

Do different methods for measuring joint moment asymmetry give the same results?

Gait asymmetry is defined as a loss of perfect agreement between the dominant and non-dominant lower limbs. Conflicting results from gait asymmetry studies may be due to different definitions of asymmetry, different research methods, and/or different variables and formulas used for asymmetry calculation. As a result, this makes it difficult to compare joint asymmetry values between studies. An accurate and precise understanding of asymmetry during human walking is an important step towards developing enhanced rehabilitation protocols for pathological gait. This study examined bilateral lower extremity joint moment asymmetry during the stance phase of walking using three different methods. Fourteen male children (with flat feet) aged 8-14 years participated in this study. The three-dimensional lower limb kinetics was evaluated during a comfortable gait. Then, right and left lower limb joint moments were used to calculate the joint moment asymmetry via three different methods (Lathrop-Lambach method: equation used by Lathrop-Lambach et al. (2014); Su method: equation used by Su et al. (2015); Nigg method: equation used by Nigg et al. (2013)). Repeated-measures ANOVAs (α = 0.05) were used to compare the values of net joint moment asymmetry calculated by the three methods. The results of the statistical analyses found that the amounts of moment symmetry between limbs calculated by the first two methods were significantly greater than that of using the Nigg method (except for the values of the frontal ankle moment computed by the Lathrop-Lambach method). Furthermore, in comparison of the first two methods, using the Su method showed a reduction in moment asymmetry for all joints and for all moments (p < 0.05). We conclude that, although all of three common methods for determining asymmetry between limbs have documented merit, they sometimes differ dramatically in results.

The effect of foot orthoses on joint moment asymmetry in male children with flexible flat feet.

INTRODUCTION: It has been widely postulated that structural and functional misalignments of the foot, such as flat foot, may cause mechanical deviations of the lower limb during walking. The aim of this study was to investigate the effect of foot orthoses on lower extremity joint moment asymmetry during the stance phase of walking in children with asymptomatic flexible flat feet. METHODS: Fourteen volunteer male children, clinically diagnosed with flexible flat feet, participated in this study. Subjects completed 12 walking trials at a self-selected walking speed while 3-dimensional kinematic and kinetic data were collected for two conditions: shod with no orthoses, and shod with orthoses. The gait asymmetry index for each variable for each subject was defined as: (1-(lesser moment/greater moment)) × 100. RESULTS: Results reveal no significant differences in ankle or knee joint moment asymmetry. However, the use of foot orthoses decreased asymmetry for the hip abduction moment (P = 0.04) compared to walking without orthoses and also resulted in subtle, non-significant increases in frontal plane subtalar and sagittal plane knee and hip joints moment asymmetry. CONCLUSION: We conclude that foot orthoses decrease frontal plane hip joint moment asymmetry, but have little effect on ankle and knee joint asymmetry.

The effects of low arched feet on lower limb joints moment asymmetry during gait in children: A cross sectional study.

BACKGROUND: The prevalence of flexible flat feet in children was reported to be up to 20% in previous studies. However, the role of foot type in the development of musculoskeletal injuries is less clear, particularly in children. The purpose of this study was to investigate the differences in the joint moment asymmetry in children with flexible flat feet and healthy matched control subjects. METHODS: Fourteen male children with flexible flat feet and 15 healthy control subjects served as the sample of the study. Three dimensional kinematics and kinetic data were collected using a Vicon camera system and two Kistler force platforms during walking. Then between-limb asymmetry was examined for each joint moment. RESULTS: Normal individuals experienced higher asymmetry in the ankle eversion and the external rotation moments than the flat feet group. Asymmetry indices in the knee abduction, adduction, and the internal rotation moments in the flat feet group were higher than that in the normal group by 15%, 24% and 13%, respectively. Furthermore, in comparison of the two groups, individuals with flat feet had higher asymmetry in the hip flexion moment as well as the hip abduction moment. CONCLUSIONS: In order to provide appropriate protocols or footwear design for male children with flat feet, clinicians need to understand that flat feet children do not have higher levels of joint moment asymmetry as compared to normal children in all joints and all planes; consequently, they must differentiate their treatments for each specific joint. However, further larger study is warranted.

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.