Materials and Reagents

1. Laboratory-bred mice

   Note: Both male and female mice were used for the test. The conditions described in this study (bar size and distance from the camera to bar) were suitable for over 12-week-old mice. Mice were housed in groups of 3–5 per cage and kept in a room with controlled temperature (~23 °C) and humidity (50–60%) under a 12-h light/dark cycle (lights on at 8:30 AM) with ad libitum access to food and water.

Equipment

1. iPhone 8 (MQ842J/A, Apple)

   Notes:

   1. Slow-motion video support for 1,080 pixel at 120 or 240 frames per second (fps), video stabilization, and continuous autofocus video.

   2. The 240 fps slow-motion video support is available on almost all iPhone 6 and later models; therefore, it can be applied to models other than the iPhone 8.

2. Tripod

3. Hair removal cream

4. Black marker pen

5. Steel jump bar with carbon plates

   Note: Dimensions: H: 0.8 cm (0.4 cm + 0.4 cm) × W: 4.5 cm × L: 100 cm.

6. Plastic ruler

7. Anesthesia machine with sevoflurane

   Note: This was used for a short time to mark the landmarks described below.

Software

1. Tracker (https://physlets.org/tracker/)

2. ImageJ software (https://imagej.nih.gov/ij/)

3. Microsoft Excel (Microsoft)

Procedure