AFAA Personal Trainer Certification Practice Exam

The caliper should be positioned perpendicular to the skinfold when measuring skinfold thickness. This orientation is essential because it ensures that the measurement accurately reflects the thickness of the subcutaneous fat layer. When the caliper is perpendicular, it captures the full extent of the fold without introducing measurement errors that could result from an angled approach. Positioning the caliper this way allows for consistent readings across different measurements, which is crucial for tracking changes over time and for ensuring that results are comparable between different individuals and sessions. Proper technique in caliper placement is vital for the validity of the skinfold assessment, contributing to more reliable body fat estimation results. In contrast, positioning it parallel, diagonal, or at a 45-degree angle would not yield accurate measurements as they would not adequately encompass the entire thickness of the skinfold, potentially leading to underestimations or overestimations of body fat levels.