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.

Ground reaction forces during stair ascending and descending in congenitally blind and sighted individuals.

BACKGROUND: Stair ascending and descending are common in daily life activities which are challenging for blind individuals. Visual information plays an important role in controlling an individual's movements. However, the relationship between visual information and stair ascending and descending is poorly understood. OBJECTIVE: The aim of this study was to investigate how blindness alters the ground reaction force (GRF) components during ascending and descending the stairs. METHODS: Ten individuals with congenital blindness and 10 able-bodied sighted individuals were served as experimental (EG) and control groups (CG), respectively. The GRFs were recorded during stair ascending and descending tasks using a portable 40 × 40 cm Kistler force plate which was placed on a firm stair. CG repeated the ascending/descending tasks in both open and closed-eyes conditions. For within and between groups comparisons the repeated measure ANOVA and MANOVA tests were used, respectively. The significance level was set at p < 0.05 for all comparisons. RESULTS: In ascending task, there was not any significant between group differences on GRF components. However, closing the eyes in CG resulted in a significant decrease in some GRF components in the stair descending (p < 0.05). The GRF components of the stair descending in CG with open and closed-eyes were significantly different from those in the blind group; however, the differences were less in closed-eyes. SIGNIFICANCE: The GRF in the stair descent was similar in both blind and sighted individuals with closed-eyes condition, that it can increase the risk of falling in blind people. As a result, the provision of tools and equipment for the blind in descent conditions is essential.

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.

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.

Lower limb muscle activity during gait in individuals with hearing loss.

The objective of this study was to investigate the electrical activity of lower limb muscles during gait in an able-bodied control group and in deaf individuals. Thirty male children were equally divided into a control group and a group of deaf children. A portable EMG system was used to record the activity of the bilateral tibialis anterior, gastrocnemius medialis and vastus lateralis muscles during barefoot walking with and without dual task. For EMG analysis, the average root mean square (RMS) values of the five trials were calculated and then normalized based on the peak RMS obtained by the maximum isometric voluntary contraction. MANOVA test was used for between group comparisons. The significance level was set at p < 0.05 for all analyses. The findings indicated that gait speed in children with hearing loss was smaller than that in control group. Dual task resulted in a decreased walking speed of children with hearing loss. The activities of tibialis anterior muscle in terminal stance phase (p = 0.040), medial gastrocnemius muscle in loading response and initial swing phases (p < 0.05), and vastus lateralis muscle in the terminal stance and pre swing phases (p < 0.05) were greater in deaf group. In deaf children the gait speed was reduced and the muscle activity was increased with respect to those in control group. This altered gait speed and muscle activity is suggestive of a lower mechanical efficiency of gait in deaf children.

Gait ground reaction force characteristics in deaf and hearing children.

The link between gait parameters and hearing loss is not well understood. The objective of this study was to investigate the effects of the gait ground reaction forces, their time to peak, vertical loading rate, impulses and free moment during gait in deaf and hearing children. Thirty male children were equally divided into a healthy group and a group with hearing loss problems (Deaf group). Ground reaction forces were analyzed during barefoot walking. MANOVA test was used for between group comparisons. The significance level was set at p<0.05 for all analyses. Hearing loss was associated with increased propulsion lateral-medial ground reaction force (p=0.031), its time to peak (p=0.008), and lateral- medial impulse (p=0.018). Similar vertical reaction forces were observed in both groups (p>0.05). Positive peak of free moments in the healthy group was significantly greater than that in the deaf group (p=0.004). In conclusion, the results reveal that gait ground reaction force components in deaf children may have clinical values for rehabilitation of these subjects.

The effect of dual task and executive training on pattern of gait in older adults with balance impairment: A Randomized controlled trial.

OBJECTIVE: The purpose of this study was to compare the effect of two different approaches of dual-task training and executive training on pattern of gait in older adults with balance impairment. METHODS: Thirty older adults with the mean age of 73.8 participated in the study. They scored 52 or less on the Berg Balance Scale (BBS), and walked with a self-selected gait speed of 1.1m/s or less. Participants were randomly assigned to one of the three groups: experimental group one (cognitive dual-task (CDT) training) that focused on gait performance under dual task condition; experimental group two (executive function (EF) training) who underwent 3 types of training on working memory, inhibition, speed of processing; and a control group. Subjects walked 10 m, under single-task and dual-task (DT) conditions where kinematics parameters were recorded. Participants in experimental groups received 45-min training sessions, 3 times a week for 8 weeks. The data obtained was analyzed using repeated measure at a criterion p-value of 0.05. RESULTS: The results showed that after training, changes of walking speed, length of stride and step, times of stride, step, single support, and double support, were significant at p<0.05. Asymmetry index in walking with dual task condition increased significantly, but after training asymmetry in DT condition decreased significantly in EF group. CONCLUSIONS: Both training groups showed improvements in gait parameters in the post test compared with that in the control group; however, in EF training group, symmetry of limbs and inter-coordination, improved more than that in CDT group.

The effect of interventional proprioceptive training on static balance and gait in deaf children.

Children with hearing impairment have balance and motor deficits primarily due to concomitant damage to the vestibular structures. Although early intervention focused on the development of communication skills, investigations of intervention for the amelioration of balance deficits in children with hearing loss have been minimal and inconclusive. Therefore, using an experimental design, the present study investigated the effect of a 12-session exercise balance program based on proprioception training on balance and gait in deaf as compared with hearing schoolchildren. The subjects, 10 deaf and 10 typically developing children were assigned to an experimental and a control group respectively. Taking up the initial differences between the groups through a pretest under different conditions, the participants in the experimental group went through a 12-session intervention program including static and dynamic training with emphasis on proprioceptive system. After this, the participants were tested again. The data obtained was analyzed using repeated measure. A comparison between the control and experimental groups revealed that the intervention program had not significantly increased gait velocity while it had significantly decreased the amount of sway. Thus, it was concluded that an exercise program that enhances somatosensory ability can result in improved balance in deaf children.