A procedure to refine joint kinematic assessments: Functional Alignment

Area of Science:

• Biomechanics
• Orthopedics
• Kinesiology

Background:

• Accurate determination of joint rotational axes is crucial for understanding joint function and dysfunction.
• Existing methods often rely on marker-based tracking, which can be subject to errors and limitations.
• Reanalysis of previously published biomechanical data is challenging due to differing methodologies.

Purpose of the Study:

• To introduce Functional Alignment, a new method for determining the primary rotational axis and movement of joints.
• To provide a framework for unifying biomechanical research by enabling reanalysis of existing datasets.
• To explore novel comparisons of kinematic joint features.

Main Methods:

• Analysis based on spatial positions rather than temporal sequences.
• Utilizing derived joint rotation matrices instead of marker data.
• Employing two unique descriptors for joint axis orientation, independent of segment perspectives.

Main Results:

• Functional Alignment allows for the reanalysis of published biomechanical results.
• The method provides a basis for unifying perspectives across different research efforts.
• Joint axis orientation descriptors can be obtained without original marker data.

Conclusions:

• Functional Alignment offers a robust and versatile method for joint kinematic analysis.
• The approach facilitates the integration and comparison of diverse biomechanical studies.
• This method opens new avenues for underappreciated kinematic joint feature comparisons.