Biomechanika běhu předškolních dětí

Mgr. Jan PLEŠEK

Doctoral thesis

The biomechanics of running in preschool children

Abstract:

The effect of footwear on running biomechanics has been studied extensively over the past two decades. Unfortunately, there is still no universal footwear recommendation to change high incidence of running related injuries in adults, adolescents or children. Some researchers have suggested that introducing minimalist footwear in early childhood could be the so-called holy grail to develop protective running pattern against running related injuries. However, there was very limited knowledge about any effects (acute or long-term effects) on foot strike kinematics or impact loading in the crucial developmental period of running skill acquisition. Therefore, the aim of this thesis was to compare the acute effect of footwear and age effect on the running biomechanics in preschool children. This thesis consisted of three studies. For the purpose of this thesis, I recruited 48 typically developing preschool children (aged 3-6 years; 26 males and 22 females) and 12 young adult people (20-24 years; 6 males and 6 females). Preschool children were divided into age groups (3-, 4-, 5- and 6-year-old; 12 children for each preschool year). All participants performed a simple running game in three different conditions (barefoot, minimalist and standard running shoes). A three-dimensional biomechanical analysis was carried out during the period of overground running. In the first study we found that 3- and 4-year-old children ran mostly with rearfoot strike regardless of footwear condition, but from age of 5 years, they shifted their foot strike towards a forefoot pattern with more plantar flexed ankle when barefoot or in minimalist shoes. Nevertheless, all groups of preschool children (3-,4-,5-, and 6 years) still ran with a rearfoot strike in standard running shoes. The second study revealed that impact loading is significantly lower when 3-year old children run barefoot compared to shod conditions (minimalist and standard running shoes). Similarly, we found practically significant differences with medium effect in 4-year old children (barefoot < minimalist shoes; barefoot < standard running shoes; no differences between minimalist and standard running shoes). No effect of footwear was found among footwear conditions from beyond the age of 5 years. Yet, the highest value loading was surprisingly observed in minimalist shoes in all age groups. The results of the third study showed age differences in impact loading between three age groups (younger preschooler aged 3-4 years; older preschoolers aged 5-6 years; young adults as a control group). There was a significant decreasing trend of impact loading with increasing age in all footwear conditions. The largest decrease of impact loading between 3-4 and 5-6 year-old children was observed in both shod conditions. On the other hand, no differences were found between preschoolers when ran barefoot. In conclusion, these results suggest that as children get older, their foot strike pattern becomes more non-rearfoot with a more plantar flexed ankle in barefoot and minimalist shoes. On the contrary, the rearfoot-midfoot strike pattern did not change over preschool age when they wore standard running shoes. Nevertheless, minimalist shoes did not fully imitate the barefoot condition in early running developmental stages (3-4 years), at least from an impact loading perspective. The professionals (e.g. teachers, coaches and trainers) whose work with preschool children should be careful and consider the foot strike pattern technique and specificity of high minimalist index footwear at these ages. In general, the time of full and load-safe use of any footwear (including minimalist shoes) for the introduction of running activities on hard surfaces probably begins at age 5-6 years.

Abstract:

The effect of footwear on running biomechanics has been studied extensively over the past two decades. Unfortunately, there is still no universal footwear recommendation to change high incidence of running related injuries in adults, adolescents or children. Some researchers have suggested that introducing minimalist footwear in early childhood could be the so-called holy grail to develop protective running pattern against running related injuries. However, there was very limited knowledge about any effects (acute or long-term effects) on foot strike kinematics or impact loading in the crucial developmental period of running skill acquisition. Therefore, the aim of this thesis was to compare the acute effect of footwear and age effect on the running biomechanics in preschool children. This thesis consisted of three studies. For the purpose of this thesis, I recruited 48 typically developing preschool children (aged 3-6 years; 26 males and 22 females) and 12 young adult people (20-24 years; 6 males and 6 females). Preschool children were divided into age groups (3-, 4-, 5- and 6-year-old; 12 children for each preschool year). All participants performed a simple running game in three different conditions (barefoot, minimalist and standard running shoes). A three-dimensional biomechanical analysis was carried out during the period of overground running. In the first study we found that 3- and 4-year-old children ran mostly with rearfoot strike regardless of footwear condition, but from age of 5 years, they shifted their foot strike towards a forefoot pattern with more plantar flexed ankle when barefoot or in minimalist shoes. Nevertheless, all groups of preschool children (3-,4-,5-, and 6 years) still ran with a rearfoot strike in standard running shoes. The second study revealed that impact loading is significantly lower when 3-year old children run barefoot compared to shod conditions (minimalist and standard running shoes). Similarly, we found practically significant differences with medium effect in 4-year old children (barefoot < minimalist shoes; barefoot < standard running shoes; no differences between minimalist and standard running shoes). No effect of footwear was found among footwear conditions from beyond the age of 5 years. Yet, the highest value loading was surprisingly observed in minimalist shoes in all age groups. The results of the third study showed age differences in impact loading between three age groups (younger preschooler aged 3-4 years; older preschoolers aged 5-6 years; young adults as a control group). There was a significant decreasing trend of impact loading with increasing age in all footwear conditions. The largest decrease of impact loading between 3-4 and 5-6 year-old children was observed in both shod conditions. On the other hand, no differences were found between preschoolers when ran barefoot. In conclusion, these results suggest that as children get older, their foot strike pattern becomes more non-rearfoot with a more plantar flexed ankle in barefoot and minimalist shoes. On the contrary, the rearfoot-midfoot strike pattern did not change over preschool age when they wore standard running shoes. Nevertheless, minimalist shoes did not fully imitate the barefoot condition in early running developmental stages (3-4 years), at least from an impact loading perspective. The professionals (e.g. teachers, coaches and trainers) whose work with preschool children should be careful and consider the foot strike pattern technique and specificity of high minimalist index footwear at these ages. In general, the time of full and load-safe use of any footwear (including minimalist shoes) for the introduction of running activities on hard surfaces probably begins at age 5-6 years.

Keywords

barefoot, minimalist shoes, standard running shoes, footwear, footstrike patterns, ground reaction forces, impact loading, loading rate, aging, development

Language used: English

Date on which the thesis was submitted / produced: 18. 11. 2022

Accessible from:: 31. 12. 2999

Thesis defence

• Supervisor: doc. Mgr. Daniel Jandačka, Ph.D., doc. Mgr. Daniel Jandačka, Ph.D.

University of Ostrava

Pedagogical Faculty

Doctoral programme / field:
Kinanthropology / Kinanthropology