Treppe

Treppe is the German word for a staircase—a connected series of steps that enables movement between levels. In architecture and building design, stairs consist of treads and risers and may include landings, handrails, and balustrades. Common configurations include straight-run, L-shaped, U-shaped, and spiral stairs. Design considerations cover safety, headroom, accessibility, and compliance with local building codes.

In physiology, Treppe, or the staircase phenomenon, refers to the gradual increase in muscle contraction strength observed during repeated stimulation at a low frequency, before full tetanus. Each successive contraction is stronger than the previous, producing a staircase-like force pattern. The effect is transient and dissipates after a rest period when the muscle returns to baseline. Treppe is thought to arise from factors such as increased muscle temperature, improved enzymatic activity, and greater availability of calcium in the sarcoplasm, which enhances cross-bridge cycling. In modern physiology, the phenomenon is often contrasted with summation and tetanus and contributes to understanding excitation-contraction coupling and muscle metabolism.

The term Treppe originates from German treppe meaning staircase and is used in both architectural and physiological contexts. In English-language texts, the phenomenon is commonly referred to as the staircase effect or Treppe.