# IN-SITU FORCES & STRAINS IN NORMAL & RECONSTRUCTED ACLS

> **NIH NIH R01** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 1993 · $150,943

## Abstract

Rupture of the anterior cruciate ligament (ACL) is relatively common and
potentially crippling, affecting active people, both young and old. ACL
injury may result in functional knee instability, secondary damage to
other knee structures, and the early onset of degenerative joint disease.
ACL reconstruction provides knee stability after ACL injury, however, it
has not been shown to restore normal knee kinematics, and many aspects of
ACL reconstruction and post-surgical rehabilitation remain problematic.
Continued advancement depends on a more quantitative understanding of the
forces and strains generated within the ACL during knee motion.

The broad aim of this project is to determine the role of the human ACL
during knee joint motion and under external loads. Using cadaveric knees,
the in-situ force and strain distribution within the ACL will be measured
with and without muscle stabilization. Data collected will then be used as
a basis for evaluating the changes in knee kinematics and graft forces
that result after ACL reconstruction. The effects of tension applied to
the replacement graft at the time of surgery on these parameters will also
be quantitatively examined.

We will employ new technology involving a Universal Force-Moment Sensor
(UFS) to determine the forces generated in the ACL under the application
of known external loads. Complex paths of human knee motion in 6 degrees-
of-freedom (DOF) will be recorded and then reproduced using an articulated
robotic manipulator. Force/moment data coupled with reproducible knee
motion will enable measurement of the in-situ forces within the ACL and
ACL replacement grafts. Because this technology permits both position and
force control of knee motion, the changes in knee kinematics resulting
from ACL reconstruction can be directly examined. A 3-D strain analysis
system will also be used to measure the strain distribution along the ACL.

Information obtained in this study will have a direct bearing on the
clinical management of ACL deficiency by providing data for surgical
reconstruction. These findings will provide improved rationale for the
selection of ACL replacement grafts, for the determination of appropriate
reconstructive techniques, and for improvement of established
rehabilitation protocols.

## Key facts

- **NIH application ID:** 3159876
- **Project number:** 2R01AR039683-04
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **SAM.gov UEI:** MKAGLD59JRL1
- **Principal Investigator:** SAVIO L-Y. WOO
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $150,943
- **Award type:** 2
- **Project period:** 1990-12-01 → 1996-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3159876

## Citation

> US National Institutes of Health, RePORTER application 3159876, IN-SITU FORCES & STRAINS IN NORMAL & RECONSTRUCTED ACLS (2R01AR039683-04). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3159876. Licensed CC0.

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