Measurement notes
For rotarod work, report the rod diameter, surface, start speed, acceleration profile, trial count, rest interval, and whether passive rotations or clinging count as failure. Keep training and test sessions separate.
Endpoint methods library
Motor coordination endpoint
Latency to fall
Time an animal remains on a rotating rod, beam, ladder, or elevated motor task before meeting a fall or failure criterion.
Unit
seconds
Readout
Elapsed time until fall or predefined failure event
Assays
Rotarod, balance beam, horizontal ladder, wire hang variants, treadmill failure tests
Decision summary
Use latency to fall when the study needs a compact motor coordination, balance, fatigue, or motor-learning readout. Do not treat it as a pure coordination measure without speed profile, training history, body weight, grip, clinging, and fatigue controls. The endpoint is strongest when the fall criterion and acceleration profile are calibrated and reported.
| Primary value | Elapsed time until fall or predefined failure event |
|---|---|
| Common units | Seconds, often capped by maximum trial duration |
| Compatible assays | Rotarod, balance beam, horizontal ladder, wire hang variants, treadmill failure tests |
| Required boundary | Start speed, acceleration or fixed speed, fall criterion, and cutoff |
| Do not infer alone | Motor learning, strength, ataxia, sedation, motivation, or fatigue mechanism |
Interpretation limit
Shorter latency can reflect impaired coordination, weakness, sedation, fatigue, high body weight, low motivation, or an apparatus mismatch. Longer latency can reflect motor learning, clinging, or strain-specific strategy rather than only better balance.
Data capture
Store trial number, speed profile, latency, speed at fall, passive-rotation flag, fall sensor event, manual override notes, body weight, training history, and rest interval.
Confound checks
- Rod diameter, surface texture, acceleration rate, or calibration mismatch.
- Clinging behavior or passive rotations counted differently across scorers.
- Insufficient habituation or unequal training before the test session.
- Body weight, grip strength, sedation, pain, anxiety, or fatigue effects.
- Ceiling effects from long maximum durations or too-easy speed profiles.
Reporting checklist
- Apparatus type, rod or beam dimensions, surface, speed range, and acceleration profile.
- Training schedule, trial count, rest interval, and maximum trial duration.
- Exact fall or failure criterion, including passive rotation rules.
- Whether latency is best trial, mean trial, learning slope, or test-day summary.
- Body weight, sex, strain, age, and exclusion criteria.
- Companion endpoints such as grip strength, gait, open-field distance, or speed at fall.
References
Evidence notes
Endpoint pages should cite the method literature behind the scored value and keep high-specificity protocol claims qualified unless the source supports them.
- Brooks SP, Dunnett SB. Tests to assess motor phenotype in mice: a user's guide. Nat Rev Neurosci. 2009. doi:10.1038/nrn2652.
- Mandillo S et al. Reliability, robustness, and reproducibility in mouse behavioral phenotyping: a cross-laboratory study. Physiol Genomics. 2008. doi:10.1152/physiolgenomics.90207.2008.
- Jones BJ, Roberts DJ. The quantitative measurement of motor inco-ordination in naive mice using an accelerating rotarod. J Pharm Pharmacol. 1968.
Related workflow paths
Endpoint articles link to adjacent products, software workflows, and sibling endpoints where the connection is useful and already routable.
Rotarod product
Motor coordination apparatus commonly used for latency-to-fall testing.
Motor activity apparatus
Product category for balance, gait, activity, and motor-function assays.
Distance traveled endpoint
Pair rotarod readouts with general locomotor activity when separating motor deficits from hypoactivity.
