Joe H. Gieck, PT, EdD, ATC

Decreased Quadriceps Activation Measured Hours Prior to a Non-Contact Anterior Cruciate Ligament Tear: A Case Report

Terry L. Grindstaff, Kate R. Jackson, J. Craig Garrison, David R. Diduch, Christopher D. Ingersoll, Joe H. Gieck

STUDY DESIGN: Case Report. BACKGROUND: Decreased quadriceps activation has been shown to be present following anterior cruciate ligament (ACL) injury, but its presence prior to ACL injury is unknown. The purpose of this case report was to describe the level of quadriceps activation measured hours before a non-contact ACL injury in an individual who previously demonstrated known biomechanical risk factors for ACL injury. CASE DESCRIPTION: A 23 year old female (height= 176.9 cm, mass= 72.4 kg), sustained a left non-contact ACL injury while landing from a jump-stop during a recreational basketball game. This case was unique because data regarding landing biomechanics and quadriceps force and activation were gathered in 2 separate, unrelated studies prior to injury. OUTCOMES: Peak external knee abduction moment (-65.3 Nm) during a drop jump landing, 8 months prior to injury, indicated elevated risk for ACL injury. Involved quadriceps central activation ratios (CAR) were obtained 1 week (CAR =0.81) and 4 hours (CAR =0.77) prior to injury. Strength and CAR (0.76) measurements changed very little within 36 hours of injury and both strength and activation (CAR =0.90) improved following surgical reconstruction and formal rehabilitation. DISCUSSION: An individual with known biomechanical risk factors for ACL injury may compound their risk for non-contact ACL injury if decreased quadriceps activation is also present.

J Orthop Sports Phys Ther., Epub 25 April 2008. doi:10.2519/jospt.2008.2761

KEY WORDS: ACL, biomechanics, knee, muscle inhibition

Reliability and Responsiveness of Disablement Measures Following Acute Ankle Sprains Among Athletes

Joe H. Gieck, David H. Perrin, Ethan Saliba, Rick W. Wilson, Bruce M. Gansneder
The minimum amount of change which represents clinical improvement following ankle sprains is unknown. This study considers the usefulness of physiological and behavioral measures commonly employed for this purpose in sports rehabilitation settings. Thirteen collegiate athletes of both genders were measured at approximately 3 and 10 days post-grade I or II ankle sprain. Volumetric displacement and sagittal plane ankle range of motion measures were used as impairment indicators. Motor ability scores (activity count) and a perceived athletic ability measure (visual analog scale) were used to indicate functional limitations. Volumetric displacement and both functional limitation measures demonstrated responsiveness to change between 2 occasions of measurement separated by 1 week. Observed changes in range of motion deficits could not be distinguished from measurement error. The results of this study suggest that behavioral measures of motor activity and perceived athletic ability may be at least as useful as physical measures of organic dysfunction for assessing clinical improvement following acute ankle sprains among athletes. J Orthop Sports Phys Ther. 1998;27(5):348-355. Key Words: ankle, sprain, behavioral measurement, physical measurement, reliability, responsiveness

A Trend Analysis of the In Vivo Quadriceps Femoris Angle-Specific Torque-Velocity Relationship

Brent L. Arnold, Joe H. Gieck, David M. Kahler, David H. Perrin, Bruce M. Gansneder
To adequately assess isokinetic human muscle performance, it is important for clinicians to understand how the muscle functions across a range of velocities. Thus, the purpose of this study was to reexamine the in vivo quadriceps torque-velocity relationship using trend analysis. Twelve uninjured university-age females performed 3 concentric and eccentric contractions at velocities of 0, 25, 50, 75, 100, 125, 150, 175, and 200�/sec on the Kin-Com isokinetic dynamometer. A trend analysis was performed on the angle-specific torques at 30, 60, and 75� of knee flexion. The results indicated that the concentric and eccentric relationships at 30� and the concentric relationship at 60� were represented by a third-order polynomial, and a linear relationship was found for concentric contractions at 75�. There were no significant trends for the eccentric relationship at 60 and 75�, suggesting that they were best described by the grand mean. These results suggest that muscular torque production varies across velocities and contraction modes and that this relationship varies depending on the joint angle of torque measurement. J Orthop Sports Phys Ther. 1997;25(5):316-322. Key Words: dynamic muscle strength, knee, joint angle