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.
![](https://rebuilt.college-park.com/wp-content/uploads/2023/06/istpatient-soleus.png)
![Soleus Logo Soleus Logo](https://rebuilt.college-park.com/wp-content/uploads/elementor/thumbs/cpi-SO-Logo-group-q9nvvmawx6vbljgaobcwl1jqdh1l7cx39phtclroi4.png)
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 cpi-VL-Logo-group](https://rebuilt.college-park.com/wp-content/uploads/elementor/thumbs/cpi-VL-Logo-group-q9nvvp4fhoz6kdc77uksaiu45mnoug8aa3g9sfnhzg.png)
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.
![](https://rebuilt.college-park.com/wp-content/uploads/2023/06/istpatient-velocity.png)
![](https://rebuilt.college-park.com/wp-content/uploads/2023/06/istpatient-celsus.png)
![cpi-CS-Logo-group cpi-CS-Logo-group](https://rebuilt.college-park.com/wp-content/uploads/elementor/thumbs/cpi-CS-Logo-group-q9nvvkf8jisqybj0zajng20t6paurypmlg6ue1uguk.png)
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](https://rebuilt.college-park.com/wp-content/uploads/2020/01/soleus-walking-271x300.png)
Walking
![Moderate - Soleus](https://rebuilt.college-park.com/wp-content/uploads/2020/01/soleus-moderate-271x300.png)
Moderate Activity
![High - Soleus](https://rebuilt.college-park.com/wp-content/uploads/2020/01/soleus-high-271x300.png)
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.