Investigation of the use of the arms in recovering from postural perturbations

---

Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Eğitim Fakültesi, Beden Eğitimi ve Spor Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: EMRE AK

Danışman: MEHMET SETTAR KOÇAK

Özet:

Despite extensive preventive efforts, falls continue to be a major source of morbidity and mortality Understanding the methods used to recover from falling is important to develop necessary prevention techniques. Arm movements play an important role in recovering from postural perturbations. This study aimed to understand the effects of arm rotations in three different levels of perturbation. The participants leaned forward in 5.5, 6.5 and 7.5 degrees and suddenly released by switching off the electromagnet attached on their back. A six camera motion analysis system and a force plate were used to record the kinetic and kinematic variables. Visual 3d software was used to create subject specific models. The angular momentum of the arms about the shoulder and MTP joints were calculated. The differences between 5.5 and 6.5 degrees were compared in terms of the angular momentum and the angular velocity of the arms. None of the participants were able to recover from 7.5 degrees. Significant differences were found between 5.5 and 6.5 degrees in peak negative angular momentum of the arms, and negative and positive angular velocity of the forearms. There was no significant difference between the ground reaction forces, steady state times and shoulder torques. The relationships between angular velocity of the arms and Body Mass, Stature, Moments of Inertia of the forearms and BMI were found to be significant for 6.5 degrees. In conclusion, it can be speculated that central nervous system does some very complicated calculation based on the person’s physical characteristics to create necessary kinetic and kinematic effects to recover from falling.