Integrated Spring Technology (iST®) incorporates multiple springs working together to provide a proportional response. The Soleus, Velocity, and Celsus feet use iST to achieve superior energy return, strength, and flexibility. As you go from walking to moderate activity to high-impact running or jumping, these springs engage to provide the energy return you need.
Soleus Logo

The Soleus was the first to feature Integrated Spring Technology (iST®), providing natural movement with superior range of motion. The unique, scaled design also provides 10 mm of vertical compliance for unbeatable comfort. The Intelliweave® composite springs respond to varying impacts, so the Soleus accommodates your lifestyle whether you’re simply walking through the grocery store or training for the Paralympics. 

cpi-VL-Logo-group
The Velocity’s coupled toe springs work together to provide a progressive, dynamic response. The smooth roll-over makes for a comfortable walking foot that kicks into gear during high impact activities. If you’re a thrill seeker, you’ll appreciate this foot’s high functionality and no maintenance to keep you on the go.
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The Celsus brings College Park’s innovative Integrated Spring Technology (iST®) into a lower impact design. The foot provides smooth, stable transitions with each step. Durable yet lightweight, the Celsus provides anatomical function for low to moderate impact patients.

Walking - Soleus
Walking
Moderate - Soleus
Moderate Activity
High - Soleus
High Activity
As you go from walking to moderate activity to high-impact running or jumping, these springs engage to provide the energy return you need.