Visual Binocular Disorders and Their Relationship with Baropodometric Parameters: A Cross-Association Study

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.

INVESTIGATION OF PLANTAR PRESSURE AND PLANTAR IMBALANCES IN THE STATIC PHASE OF KARATE DO ATHLETES

The study aims to investigate the parameters offered by the baropodometric examination on a group of athletes practicing the martial art Karate Do (20 subjects, 16 girls and 4 boys, average age 13.55 ± 2.74, height 163 cm ± 8.47 , weight 54.50 kg ± 8.84, BMI (body index mass) of 20.46 ± 2.90 and seniority in sports activity of 5.27 years ± 2.74). The purpose of the research is to determine the changes related to the value of the plantar surfaces, the pressures for the dominant and non-dominant lower segments, the positioning of the pressure center in relation to the support polygon and the imbalances in the sole of the foot. The testing was performed using the FreeMed baropodometric platform and the FreeStep by Sensor Medica software, in the last week of February 2021, at the Research Center for Human Performance within the Faculty of Physical Education and Sports, “Dunărea de Jos” University from Galați. Results: Placing the maximum pressure point / P.max in the forefoot area is an exception, only one case being reported with this distribution, the rest having P.max located at the rearfoot level. Comparison of the averages between the variables recorded for the left foot vs. the right foot highlights higher values of the dominant / right foot, but these differences are significant only for the values of the plantar pressure in the forefoot area and for the total load on the entire plantar surface / total load (p <.05). The comparison between the averages of the surfaces and the loads of each separate foot (for the forefoot and rearfoot areas) highlights major differences only for the values of the contact surfaces, the forefoot area being significantly larger than the rearfoot area (p <.05). Close average values with small and insignificant differences are reported for each foot between the forefoot and rearfoot areas when comparing the body pressure / load percent and weight ratio percent, indicating a balanced pressure distribution between the front and back area for each leg. The investigation was also useful by detecting the existing imbalances at the plantar level, for one or both legs, being also reported cases of hollow, flat and mixed foot. These plantar disturbances can negatively affect all the overlying / upper joints, but especially the body posture, thus being able to cause pain in the lumbar region, limiting the performance activity and causing even the withdrawal of the athletes. We recommend that after identifying the syndromes at the ankle joint, to implement personalized plantar supports, which should be introduced in sports shoes in order to balance the architecture of the foot sole. Keywords: karate do, plantar pressures, baropodometric analysis, load, rearfoot, forefoot, maximum pressure,

Changes in plantar load distribution in legally blind subjects

We investigated the impact of visual impairment on balance control. We measured the center of pressure (COP) between the two feet and plantar surface pressures on each foot in 18 normal-sighted participants and compared their data with measures from 18 legally blind participants, either acquired or congenital. Pressures were measured in open- and closed-eye conditions using a baropodometric resistive plate. In the eyes-open condition, there were no differences between the sighted and legally blind groups in COP displacement. However, participants with visual loss had significantly increased pressures in two metatarsal regions (M1 and M2 zones) of the plantar surface in both viewing conditions (p < 0.05). The differences in pressure measures between the normally sighted and legally blind groups could be attributed mainly to the subgroup of subjects with acquired impairment. Our findings suggest that subjects with visual impairment present increased metatarsal pressures (i.e. forefoot), not yet associated to anterior displacement of COP or impaired balance control.