A low-cost instrumented spatial linkage accurately determines ASIS position during cycle ergometry.

Area of Science:

• Biomechanics
• Kinesiology
• Sports Engineering

Background:

• Accurate measurement of skeletal landmarks like the anterior superior iliac spine (ASIS) is crucial for understanding cyclist biomechanics.
• Traditional methods may have limitations in accuracy or cost-effectiveness for dynamic analysis.

Purpose of the Study:

• To develop and validate an alternative method for determining the ASIS position during cycling.
• To evaluate the accuracy and cost-effectiveness of an instrumented spatial linkage (ISL) system for 2D kinematic data collection.

Main Methods:

• Development of a two-segment ISL system using aluminum segments, bearings, and digital encoders.
• Static testing against a calibration plate and dynamic testing against a video-based motion capture system.
• Data collection from four trained cyclists at three different pedaling rates.

Main Results:

• Static testing showed minimal mean horizontal (0.03 +/- 0.21 mm) and vertical (-0.13 +/- 0.59 mm) errors.
• Dynamic comparison with motion capture yielded mean errors of 0.30 +/- 0.55 mm (horizontal) and -0.27 +/- 0.60 mm (vertical).
• The ISL system demonstrated high accuracy and agreement with a gold-standard system.

Conclusions:

• The developed ISL system is a cost-effective, accurate, and valid tool for obtaining 2D kinematic data of the ASIS during cycling.
• This method offers a reliable approach for analyzing the range of motion typical in cycling.
• The findings support the use of ISL systems in sports biomechanics research and applications.