Link-segments
Luke Macdonald
1
Biomechanical effects of daily physical activity on the lower limb
Kasim Serbest, Murat Cilli, Osman Eldogan. Acta Orthop Traumatol Turc (2015) 49:85-90
Subjects: This study involved one, 26-year-old male volunteer.
Main methods: Anthropometric properties of the subject were taken to carry out the kinematic
and kinetic analysis. The analysis was calculated with the help of a CAD software. A human
body representation of the subject was created in MATLAB. Link-segment model used in this
study included the foot, leg, thigh, Trunk, arm and forearm. Because all the joint move in unison
during the examination, the model was created taking half of the sagittal view. Reflective
markers were placed at the tip of the toe, ankle joint, top of the femur, anterior superior iliac
spine, tip of the Humerus, elbow joint, and ulnar styloid process. Subject was recorded by one
digital video camera. Five different trials were completed, sit to stand from 20cm, and 40cm,
crouch down-stand up, and climbing stairs 10cm tall and 20cm tall.
Outcome measures: Measures for this study were the relationship between reaction forces
calculated by the link segment model and ground reaction forces collected using a force plate.
Additionally, joint torques were also calculated for the ankle, knee, and hip.
Results: There was so significant differences between ground reaction forces collected from the
force plate and those from the model. The largest difference was seen in the calculation of the 20
cm sit to stand movement. Largest joint torques was found about the knee joint on the stair
climb, with strain increasing as height of stairs increase. Lowest torque occurred at the hip joint;
the crouch down stands up but the most stress on the hip but was smaller than other joints.
Conclusion: In conclusion, an accurate measurement of joint moments can be collected from a
link segment model without the use of equipment that may hinder the athlete’s performance.
This data may be beneficial for the development of prosthesis target at lower extremities.
Comments: Despite the relatively simple goal of the paper, the authors could have done more to
provide evidence of the link segments accuracy compared to other methods of data collection.
Additionally, in the results section of the paper they could have better explained the purpose of
each graph in relation to the overall theme of the paper, instead of just telling what they are.
future studies that focus on the same topics could benefit from testing the link segment model
against different biomechanical measures.