Closed-loop multibody kinematic optimization coupled with double calibration improves scapular kinematic estimates in...

Area of Science:

• Biomechanics
• Kinesiology
• Human Movement Analysis

Background:

• Estimating scapular kinematics non-invasively faces challenges due to soft tissue artifacts.
• Accurate scapular motion assessment is crucial for understanding upper limb function and diagnosing pathologies.

Purpose of the Study:

• To develop and evaluate novel procedures for estimating scapular kinematics.
• To combine closed kinematic chain optimization with double calibration techniques.

Main Methods:

• Sixteen healthy volunteers performed static postures and movements.
• Scapulo-thoracic angles were computed using a reference scapula locator, closed-loop multibody kinematic optimization (Ell), and double calibration (DClin, DCexp, DClog).
• Double calibration methods were adjusted to match reference measurements at the movement's end.

Main Results:

• Linear (DClin) and logarithmic (DClog) double calibration significantly reduced scapulo-thoracic misorientation (p < 0.01) by 9° to 32° in the latter two-thirds of movements.
• The positive effects of DClin and DClog extended to half the movement duration for arm elevation and specific daily activities.
• These methods demonstrated efficiency and speed in improving scapular kinematic estimates.

Conclusions:

• Coupling double calibration (linear or logarithmic) with closed-loop multibody kinematic optimization is effective for enhancing scapular kinematic estimation.
• This combined approach offers an efficient and fast solution for improving non-invasive scapular motion analysis in healthy populations.
• The developed methods address soft tissue artifact issues, leading to more reliable biomechanical data.