Ilaria Masci: Quantitative assessment of locomotor skills development in childhood. The running paradigm

by Ilaria Masci, E. Bergamini, G. Vannozzi, N. Getchell, A. Cappozzo (University of Rome Foro Italico, Italy)

Purpose: Running is one of the motor skills humans adopt to accomplish the important task of upright locomotion. Early appearing forms of running coordination are qualitatively different from later/advanced forms of coordination [1]. There are published intra-skill developmental sequences useful to provide information about running level in childhood. Even though qualitative assessment is usually fast and easy to practice, it suffers from a low sensitivity and it is dependent on subjective evaluation. Quantitative human movement analysis using Wearable Inertial Sensor Devices (WISD) may be considered as an alternative approach. Aim of the study was to examine the use of a quantitative approach based on WISD data to evaluate developmental differences in running skill in childhood.

Methods: 25 children (age: 7±2.7y.o.; mass: 23.5 ±12.1kg; leg length: 0.63±0.07m) performed running trials at their own maximum speed on a distance of 18m. A WISD (FreeSense, Sensorize s.r.l.) was positioned around the child pelvis to measure 3D linear accelerations. Moreover, video data was collected using a commercial digital video camera and analyzed to determine subject’s Developmental Level of the Leg Action (DLLA) [2]. The following parameters were calculated: flight and stance durations (t_f and t_s) for each running cycle; number of steps (N_s); running frequency (f_r) and mean velocity (v_m).

Results: Video analysis allowed to identify only 2 out of 3 DLLAs among the available sample. Using the mentioned DLLA scale, 20 subjects fell into DLLA₂ and 5 into DLLA₃. Subjects with DLLA₂ and DLLA₃ exhibited slightly different t_f (0.09±0.02s vs 0.08±0.02s), t_s (0.16±0.02s vs 0.18±0.02s) and f_r (4.04±0.3Hz vs 3.84±0.3Hz). N_s and v_m presented more marked differences between DLLA₂ and DLLA₃: 21.3±1.3 vs 15.6±2.2 and 2.9±0.2ms^-1 vs 4±0.4ms^-1, respectively.

Discussion: Time durations slightly varied with DLLA and age, but not significantly. Consistently with previous works [3], f_r presented a mean value of 4Hz and confirmed to be inappropriate to detect developmental differences in the individual running skill. Conversely, v_m and N_s were significantly different among DLLAs [4] and can be fruitfully used for running skill developmental assessment. Differences were emphasized when normalization procedures were taken into account using the available anthropometric parameters. Extending recruitment to DLLA₁ children (2-4 y.o.) and including further kinematic parameters are critical factors for improving the ability to assess child developmental level based on quantitative evaluation. This issue may give an important drive towards the proposal of an objective in-field tool for assessing fundamental movement skills in children.

References

1. Savelsbergh et al. Development of movement co-ordination in children. Routledge, NY, 2003.

2. Haywood and Getchell. Life span motor development, V Ed., Champaign IL, 2009.

3. Schepens B et al. J Physiol 1998; 509(Pt 3): 927-940.

4. Payne and Isaacs. Human motor development: a lifespan approach. McGraw-Hill, NY, 2008.