Investigating the Effectiveness and Benefits of a 3D Printed Ladder for Rat Resistance Training Compared to a Previously Published Model

Authors

Raghav D. Sharma, Southwestern UniversityFollow

Abstract

PURPOSE: To document and assess the training of rats using a new design and 3D printed ladder. The results were compared to the same rats climbing a ladder which is similar to ladders used in the majority of previous research. The rungs of the previous ladder were in the shape of a cylinder whereas the new model had rectangular flat steps. Rats were expected to exhibit different biomechanics while climbing the two different ladder models. In the new model we expected rats to use plant and push climbing (PPC) where rats put their entire foot on the step and push with their lower extremities. When rats climbed the previous model we expected grip and push climbing (GPC) biomechanics. GPC is when rats hook their toes around each rung and push off with less surface area from their feet. METHODS: Long Evans rats (n=6) were used for this study and were bred in the animal facilities on campus. The ladder (new design) used in this study was printed using a Bambu Lab X1 Carbon printer (0.20mm strength @BBL X1C; 15% rectilinear infill; support enabled) and used PLA plastic filament. Total filament cost of this ladder was 2393.1 grams (PLA Basic; Bambu Lab) for the full 1.08 meter build height and 0.09 meter width. The new model was designed to incorporate 4 different incline settings (5º, 30º, 60º, and 85º). The previous ladder model was bought from Otto Environmental (Adjustable ladder rung test apparatus for rats) and is a single incline model set at 90º. To increase resistance, weights were fastened to the rat’s tails using hypoallergenic adhesive medical tape. All animal protocols were approved by the Southwestern University Institutional Animal Care and Use Committee (IACUC Stokes_1025). Video documentation of climbing was done using an iPhone 16 Pro Max. RESULTS: All rats exhibited exemplary climbing behavior during acclimation at the 5º,  30º,  and 60º inclines on the new ladder design. Rats climbed successfully with weights attached to them up to 90% of their body weight during training. Some rats refused to continue climbing at 85º incline with additional weight added. Rats exhibited PPC while climbing at lower inclines of the new ladder model. GPC was exhibited while climbing the old model and the 85º incline of the new ladder model. CONCLUSION: Acclimation to the ladder was successful and required no addition of a negative stimulus. No rat failed during acclimation which suggested that failure in training was due to the training protocol. Rats demonstrated the ability to climb this ladder at all inclines and exhibited PPC as opposed to GPC. PPC was more substantial at lower incline settings than 85º. This finding could be due to there being less surface area of the step available for the rat to place their feet on at the 85º incline because the steps were almost directly on top of each other. The difference in climbing biomechanics between 60º and 85º incline suggests that there may be a critical angle at the highest incline where PPC is still possible with the new ladder. Future research will focus on quantitatively comparing the previous ladder model directly to the new model as well as establishing what incline is most effective for strength training and muscle hypertrophy.

Recommended Citation

Sharma, Raghav D. (2026) "Investigating the Effectiveness and Benefits of a 3D Printed Ladder for Rat Resistance Training Compared to a Previously Published Model," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 73.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/73