UCBL & Force Systems
The University of California Biomechanics Lab orthosis, better known as a UCBL orthosis has been commonly used to treat many disorders resulting from low tone. As of late I have been hearing much debate over the three point force systems at play. Many of these arguments have been correct because several three point force systems can be used depending on the motions that require control. This post will go over three types of force systems, all of which will have an inverse systems that can be used when control of the opposite motion is needed.
Keep in mind that every three-point force system has two forces directed towards the same plane with one opposing force. This of course changes when more forces are required, such as a four-point force system.
The following force systems are generally used to control excessive pronation and the accompanying deformations: forefoot abduction, calcaneal valgum, and in some cases forefoot inversion.
Mid-foot depression
2 forces located laterally and directed inferiorly: in this instance the two inferiorly directed forces are supplied primarily during weight bearing.
Force location: along the 1st metatarsal
Force location: along the calcaneus
1 opposing force located medially and superiorly directed: applied with long corrective arch support provided by the UCBL.
Force location: along the medial longitudinal arch
Forefoot abduction:
2 forces located laterally and directed medially
Force location: along the fifth metatarsal
Force location: along the lateral calcaneus (also preventing excessive calcaneal valgus)
1 opposing force located medially and directed laterally
Force location: along the medial longitudinal arch
Forefoot Inversion:
2 forces located medially and inferiorly directed
Force location: along the side of the first metatarsal
Force location: along the calcaneus
1 opposing force located laterally and directed superiorly
Force location: along the fifth metatarsal
