Influence Of Carrying Different Weights Of School Bags On Gait Phase And Plantar Pressure In Obese Children's Stair Walking

Ojectives: Both load carriage and stair walking are frequently encountered during the course of normal daily activities for obese children.Previous studies had investigated that exceed heavy school bag would influence children's posture gait and plantar pressure during level walking.Pertaining to obese children are focus on pathology and daily activities inconveniently in unload conditions.However,research on sports siomechanics for obese chlidren load carriage during stair walking is rare so for.To examine the influence of carrying different weights of school bags on gait phase and plantar pressure in obese children's stair walking is this study objectives,in order to know,is there potential risk for obese children when they loading heavy school bag during stair walking,and provide somen suggestions for relieve load.Methodology:Sixteen male students aged 11.19±0.66 years (bodyweight75.26±15.99kg kg; body height148.85±14.07cm cm;body index 29.78±4.10 kg/m²)were recruited randomly from shi mu yuan elementary schoolto serve as subjects.A camera (sony₁000e, Japan)was used to capturing gait parameters during children load differents weight of schoolbag climing stairs,aimed to collectiving kinetic data, two force plates (KISTLER,9287BA,9281CA,Siwtzerland) were embeded in the third and fourth stair respectively. Four backpack (on both shoulder)with 0%,10%, 15%, and 20%of the subjects'body weight, were used when they load ascentedand decented stairs.Each load ask children to finishied 3times smoothly.Children were asked to take a rest for 1miniute when each trial was finished and when three times trials were taked they can take a rest for five minutes. A repeated ANOVA measurement was performed to compare four difference loads for each dependent variable and the paired samples t-test was used to investigate whether there was a significant difference in each dependent variable between ascented descented stairs ,(p<0.05). Results:1. Gait parameters : In ascending the stairs ,the gait cycle duration,double support duration and stance duration were increased along with load increased and swing duration were deduced when load increased.The results showed that the gait cycle duration was significantly increased with 20% body weight when compared to the 0%,10% and10% load conditions .When carrying an backpack with load of 15% body weight or above induced significant increased in the double support duration and carrying an backpack with load of 10% body weight or above induced significant difference in the stance duration and swing duration. In descending the stairs , the gait cycle duration,double support duration and stance duration were increased along with load increased and swing duration were deduced when load increased.The results showed that carrying an backpack with load of 20% body weight or above induced significant difference in the gait cycle duration,double support duration ,stance duration and swing duration when compared to the 0% load condition. When compared to acsent,we found that stair decent showed significantly greater in the gait cycle duration for all conditions than ascent and showed significantly greater in the double support duration in 10,15% and20% conditions.2. Vertical ground reaction forces: In ascending the stairs ,the first peak,minimum and the second peak were increased along with load increased .The results showed that carrying an backpack with load of 10% body weight or above induced significant increased when compared to the 0% load condition. When carrying the backpack, loads of 10% of body weight or above significantly increased the maximum (first) peak force in decent. When compared to acsent,we found that stair decent showed significantly greater in th maximum peak force for four loads.3. Medial/Lateral ground reaction forces: Statistical analysis showed that there was no significant in the medial/lateral ground reaction forces for four conditions whatever asent or decent. In ascending the stairs,the maximum peak force is range from 0.069 time body weight to 0.075. In descending the stairs, the maximum peak force is range from 0.12 time body weight to 0.13. When compared to acsent,we found that stair decent showed significantly greater in th maximum peak force for four loads.4. Anterior/Posterior ground reaction forces: The results showed that there was no significant in the anterior/posterio ground reaction forces for four conditions whatever asent or decent. In ascending the stairs,the maximum peak force is range from 0.12 time body weight to 0.13 time body weight. In descending the stairs, the maximum peak force is range from 0.16 time body weight to 0.17 time body weight. When compared to acsent,we found that stair decent showed significantly greater in th maximum peak force for four loads.Conclusions:1.In ascending the stairs and in descending the stairs, the gait cycle duration was increased along with load increased , in other words,the walking velocity was reduced along with load increased. The gait cycle duration,double support duration and stance duration were increased along with load increased and swing duration were deduced when load increased ,that is to say,children's stability was decreased as the load increased. In orde to keep balangce,subjects were forced to compensate by shortening their swing phase or adding their stance phase, which may be an attempt to minimize the duration of un- steady single-limb stance.2.The results showed that carrying an backpack with load of 10% body weight or above induced significant increased in the vertical ground reaction forces . The increased load carried on the back would bring to the potential risk of lower limb jionts muscle fiber damage when the load becomes too great . Statistical analysis showed that there was no significant in the medial/lateral ground reaction forces for four conditions whatever asent or decent.The same situation for the the anterior/posterio ground reaction forces . When compared to acsent,we found that stair decent showed significantly greater in the maximum peak force for four loads. As to the medial/lateral ground reaction forces, We concluded that during decent children showed more instability than ascent. As to the the the anterior/posterio ground reaction forces, stair decent showed significantly greater in the maximum peak force than stair ascent,just because during descent the forefoot touchdown ground ,add exceed vertical ground reaction forces, It postulated that obese children are at an increased risk of developing foot pathologies due to increased plantar loads being borne by the small forefoot bones. caution should be exercised in relation to the load carried, , and the use of shoes with proper cushioning ability.3.Consider gait parameters and plantar pressure ,We concluded that back pack weight should not exceed 10% of body weight in obese boys.