Effect Of Tibial Rotation Research Articles

Tibial External Rotation Test for Patellar Instability.

There is no dynamic physical examination test that reproduces patellar instability or the effect of tibial rotation on patellar tracking. This article describes a provocative physical examination test that can reproduce lateral patellar subluxation: the tibial external rotation test (TERT). The principle behind the TERT is to vary the quadriceps angle (Q-angle) by changing the rotation of the tibia with the knee at 90° of flexion and asking the patient to forcefully extend the knee against resistance. If the patella subluxates at about 25° of flexion when the tibia is held in the externally rotated position and the knee is extended against resistance (i.e., with an increased Q-angle) but is more stable when the same is done when the tibia is internally rotated, the test is positive. The TERT confirmed the diagnosis of patellar instability and helped determine if medialization of the tibial tubercle should be performed. The TERT is a provocative physical examination test that can cause the patella to subluxate laterally. The TERT can simulate the effect of medializing the tibial tubercle on patellar tracking. Diagnostic Level V. See Instructions for Authors for a complete description of levels of evidence.

Knee Flexor Strength and Activation Levels During Testing After ACL Reconstruction with a Semitendinosus Graft.

PURPOSE: Assessment specific to medial (MH) vs. lateral (LH) hamstrings may be indicated after graft harvesting from semitendinosus for anterior cruciate ligament (ACL) reconstruction. The purpose to the study was to assess strength and muscle activation levels of MH and LH during isometric strength testing where knee flexion was coupled with medial (MR) vs. lateral (LR) rotation of the tibia in elite athletes 1-5 years after ACL reconstruction, contrasting outcome measures with the non-surgical limb. METHODS: Maximal isometric strength of 35 athletes (18 male, 17 female) was tested with a Kin Com dynamometer at 40° and 80° of knee flexion. Participants maintained concurrent volitional MR or LR of the tibia to facilitate preferential activation of the MH and LH components, respectively. Maximum values within each of a total of four 5 second trials were thereby collected for both lower limbs. Pre-amplified, wireless surface electrodes were used to collect muscle activity of each hamstring component during testing. Maximum values of smoothed data were identified within each test condition, the highest of which was used for normalization purposes. A mixed model repeated-measures ANOVA was used for analysis and alpha set at 0.05. RESULTS: A significant interaction of limb by test position by sex was found for strength (p=0.016), as males had lower strength values for the surgical side only at 80° whereas females had lower strength at both 80° and 40° with no effect of tibial rotation. Muscle activation data did not specifically reflect this interaction found in strength measures. However, analysis of MH data showed a significant test position by sex interaction (p=0.003) across limbs, due to lower MH activation levels found at 40° compared to 80°, a difference not found for males. CONCLUSIONS: Males and females may use different strategies during rehabilitation. Inhibition of MH activation may contribute to lower strength output during testing and influence readiness of return-to-sports.

Effects of tibial rotation on Ober's test and patellar tracking

BackgroundThe purpose of this study was to investigate the effects of tibial position on ITB flexibility and patellar position. MethodsA total of 31 asymptomatic subjects (21 males, 10 females) were recruited for this investigation. Adduction angle was measured by Ober's test, and PCD was measured by ultrasonography in three different tibial rotation conditions: N, IR, and ER. ResultsRepeated measures ANOVA revealed a significant difference in adduction angle and PCD among three different tibial positions (P<0.05). Adduction angle was significantly greater in the N tibial position than in ER (P<0.05). The PCD was significantly greater in N position than in IR (P<0.05). However, the PCD was significantly smaller in IR compared with the N position (P<0.05). ConclusionsThese findings support that tibial rotation influences the flexibility of ITB and patellar positions. Therefore, excessive tibial rotation can cause inappropriate patellar positions that eventually lead to knee injury. Therapists should consider tibial rotation when measuring adduction angles because tibial rotation can change Ober's test results and contribute to the consistency of ITB length measurements. Level of evidenceLevel IV.

The Effect of Tibial Rotation on the Contribution of Medial and Lateral Hamstrings During Isometric Knee Flexion.

Background:Selective atrophy of hamstring components may result from muscle strain or graft harvesting for anterior cruciate ligament reconstruction. Assessment and rehabilitation that specifically targets medial (MH) or lateral (LH) hamstring components may improve patient outcomes. The purpose of this study was to evaluate effects of volitional tibial rotation medially (MR) versus laterally (LR) on activation levels of MH versus LH and strength measures during isometric testing of knee flexors.Hypothesis:Muscle activation of MH and LH during knee flexor strength testing will be augmented when coupled with MR and LR of the tibia, respectively, without affecting knee flexor strength measures.Study Design:Cross-sectional laboratory study.Level of Evidence:Level 3.Methods:Surface electrodes were used to record neuromuscular activity from MH and LH of the right lower limb in 40 healthy young men and women during isometric knee flexor strength testing at 40° of knee flexion, where participants maintained concurrent volitional MR or LR of the tibia. Statistical analyses of variance included general linear models for repeated measures.Results:A significant interaction was found for tibial rotation and hamstring component variables (P < 0.01). When isometric knee flexion was coupled with LR, normalized activation levels were similar for MH and LH. When performed with MR, a significant drop in LH activation led to dissimilar activation levels of the 2 components. Significantly greater strength measures were found when isometric knee flexion was performed with concurrent LR of the tibia (P < 0.01). Both sexes demonstrated the same rotation-dependent differences.Conclusion:Coupling tibial rotation with knee flexor activities primarily affects the LH component.Clinical Relevance:Strategies involving volitional tibial rotation may be considered for specific assessment/rehabilitation of the MH or LH component.

Computational Model for Mechanics of Total Knee Replacement: Effect of Tibial Rotation during Deep Flexion in Relation to Post-Cam Design

Computational Model for Mechanics of Total Knee Replacement: Effect of Tibial Rotation during Deep Flexion in Relation to Post-Cam Design

Paper # 14: The Effect of Tibial Rotation on Tibio-Femoral Joint Contact During in Vivo Dynamic Activity after Double Bundle ACL Reconstruction

In vivo knee rotation and joint contact path were evaluated after double bundle ACL reconstruction using a dynamic stereo X-ray system. Normal knee rotation was restored after reconstruction, but joint contact sliding length was altered. Although knee rotation and joint contact condition was closely related, only kinematics measurement might miss the subtle change on joint contact condition.

The Effect of Tibial Rotation on the Presence of Instability in the Anterior Cruciate Ligament Deficient Knee

The effects of tibial rotation after ACL injury have not yet been well determined. To show whether clinical outcomes such as the amount of tibial rotation can affect functional outcomes in normal and ACL deficient knees. Case control study. Research laboratory. Twenty normal subjects (Control) and 20 subjects with ACL deficient knees (ACL). Tibial rotation at 30 and 90 degrees of knee flexion was measured using an inclinometer. One-legged hop, crossover hop, figure-of-eight running and 10-m running tests were used and determined the effect(s) of tibial rotation on the outcome of the functional tests. There were significant between-group differences in internal and external rotation. The relationship between external tibial rotation and the figure-of-eight index was significantly negatively correlated. The amount of tibial rotation is greater in ACL ruptured knees than in uninjured knees, and these greater amounts of tibial rotation affected the figure-of-eight running index.

The effects of tibial rotation on posterior translation in knees in which the posterior cruciate ligament has been cut.

One of the most useful clinical tests for diagnosing an isolated injury of the posterior cruciate ligament is the posterior drawer maneuver performed with the knee in 90 degrees of flexion. Previously, it was thought that internally rotating the tibia during posterior drawer testing would decrease posterior laxity in a knee with an isolated posterior cruciate ligament injury. In this study, we evaluated the effects of internal and external tibial rotation on posterior laxity with the knee held in varying degrees of flexion after the posterior cruciate and meniscofemoral ligaments had been cut. Twenty cadaveric knees were used. Each knee was mounted in a fixture with six degrees of freedom, and anterior and posterior forces of 150 N were applied. The testing was conducted with the knee in 90 degrees, 60 degrees, 30 degrees, and 0 degrees of flexion with the tibia in neutral, internal, and external rotation. All knees were tested with the posterior cruciate and meniscofemoral ligaments intact and transected. Repeated-measures analysis of variance was used for statistical analysis. At 30 degrees, 60 degrees, and 90 degrees of flexion, there was a significant increase in posterior laxity following transection of the posterior cruciate and meniscofemoral ligaments. At 60 degrees and 90 degrees of flexion, there was significantly less posterior laxity when the tibia was held in internal compared with external rotation. At 0 degrees and 30 degrees of flexion, there was no significant difference in posterior laxity when the tibia was held in internal compared with external rotation. After the posterior cruciate and meniscofemoral ligaments had been cut, posterior laxity was significantly decreased by both internal and external rotation of the tibia. Internal tibial rotation resulted in significantly less laxity than external tibial rotation did at 60 degrees and 90 degrees of knee flexion.

The effects of tibial rotation on patellar position

The effects of external and internal tibial rotation on patellar motion were investigated using a magnetic 3Space ® tracker system (Polhemus, Colchester, VT 05446, USA). Seven fresh-frozen adult cadaver knees were used in this study. The muscle alignment of each quadriceps muscle was measured to determine the direction of loading forces. Three loading patterns were used to simulate the unresisted knee extension during sitting, standing from squatting and the stance phase of walking, with different weights applied to each quadriceps muscle at each knee flexion angle. The position of the patella, along with patellar shift, tilt and rotation was measured and compared to external or internal tibial rotation and neutral rotation. In the sitting and squatting simulations the patella showed at the terminal extension of the knee more lateral shift and a more lateral tilt with tibial external rotation than in a neutral position ( P < 0.05). In walking simulation, the patella showed more external rotation with external rotation of the tibia than with a neutral one, at the 0, 72 and 90% of the stance phase of walking ( P < 0.05). These results demonstrate the importance of external tibial rotation as a factor in the development of patellar dislocations or subluxations, especially in athletes.

Effect of Tibial Rotation on Measures of Strength and Endurance of the Knee

The purpose of this study was to determine the effect of angular tibial rotation on the muscular strength and endurance of the knee flexors and extensors. Thirteen male subjects between 23 and 40 years of age were tested in three different positions of tibial rotation; neutral, 20 degrees external and 20 degrees internal. Standard Cybex technique was follwed to determine mean peak torque and time to 50 percent fatigue in endurance testing at 180 deg·sec1 for each of the three positions. A coupling device wan designed for the Cybex dorsiflexion footplate to hold the knee in the designated position of rotation. Analysis was done using paired t-tests camparing each position of rotation with neutral. Mean peak torque at 60 deg·sec1 and time to 50 percent fatigue were significantly decreased (p < .10) for the extensors in both internal and external rotation as compared to neutral.

Effect of Tibial Rotation on Measures of Strength and Endurance of the Knee

Effect of Tibial Rotation on Measures of Strength and Endurance of the Knee