Introduction: Walking and running on a treadmill is a diffused sporting activity for wellbeing and sports specific training. Developers of fitness equipment put their efforts in enhancing the flexibility of machines that multiplies the exercises, providing different combination of effort and ambient biofidelity. Traditional motorized treadmills can be compared with non-motorized ones (Sinclair et al, 2013), flat surfaces with curved surfaces (Smoliga et al., 2015). Aim of the study was to study the effect on walking and running biomechanics at different speeds performed by a group of subjects in three different treadmills: a conventional motorized flat treadmill (Technogym Artis TRD), a passive curved treadmill (WOODWAY Curve) and an innovative tunable non-motorized curved treadmill named SkillMillTM (SKM). Methods Surface EMG of 12 muscles on right hand side of each subject were investigated applying 2 pre-gelled bipolar electrodes on each muscle: Tib.Ant.(TA), Gastr. Med. (GAM), Vastus med.(VAM), Biceps fem. (BFCL), Rectus fem. (RF), Gluteus max. (GLMA), Rectus abd. (RA), Adductor (ADCL), Erector spinae (ERS), Pect. major (PECM), Lat. dorsi (LD), Triceps brach. (TBCL). Kinematics data were collected by means of an optoelectronic system (BTS), using 12 reflective markers placed in specific bony landmarks. Eight healthy male subjects with similar level of fitness were involved. Each one was asked to walk at 6 km/h, run at 12 and 18 km/h. Walking against an additional resistance on the SKM treadmill (PWLK) was also included in the tests. EMG signals were rectified, integrated with a moving window of 200 ms, filtered at 6 Hz and normalized to the gait cycle. Signals were averaged over 5 consecutive cycles, defined between two consecutive right heel strikes. Results: Walking on non-motorized curved treadmills resulted in an increased ROM at the ankle (+10%) and the trunk (+50%); on the contrary, when running on the curved treadmills trunk ROM decreased significantly. The trunk mean forward leaning angle increased on curved treadmill, in particular with high resistance on SKM (PWLK). Peak Muscle activation resulted consistently higher in GASM, VAM, BFCL,GLMA, during PWLK than other conditions. When running on SKM at moderate and high speed, GASM and GLMA showed higher average activations than on TRD. Discussion: Results highlight the ability of an adjustable non-motorized treadmill in enhancing the muscle activation on antigravitational muscles; the combination with a curved surface widens the range of motion at the ankle but reduces the trunk ROM when running. This can be correlated with lower impact loads at the feet, as reported by the subjects, due to the curved treadmill surface.
© Copyright 2016 21st Annual Congress of the European College of Sport Science (ECSS), Vienna, 6. -9. July 2016. Veröffentlicht von University of Vienna. Alle Rechte vorbehalten. / Übersetzt mit https://www.DeepL.com/Translator