Printer Friendly

Q angle--relevance for evaluation of anterior knee pain.

INTRODUCTION: Patellofemoral pain syndrome is a descriptive term applied to patients with nonspecific anterior knee pain, and is the most common knee problem (1, 2). The pain in most patellofemoral disorders is generalized to the anterior part of the knee (3, 4). One important concept in patella femoral joint function is the quadriceps angle (Q-angle). Theoretically, a higher Q-angle increases the lateral pull of the quadriceps femoris muscle on the patella and potentiates patellofemoral disorders (5).

To understand how the Q angle contributes to knee pathologies, it's helpful to look at the anatomical relationships in the region. The patella is embedded in the quadriceps tendon.

There is a ridge on the underside of the patella that must fit in the trochlear groove between the two condyles of the femur (Figure 1). The patella moves superiorly and inferiorly in this groove during knee flexion and extension.

The patella's ability to track straight in the trochlear groove is determined by the quadriceps' angle of pull. When the Q angle is greater, the quadriceps pull the patella in a more lateral direction. The unequal pull on the patella causes increased tensile stress on soft tissues around the knee. Too much lateral pull on the patella also can drag it against the lateral femoral condyle and eventually cause degeneration of the cartilage on the underside of the patella. Problems associated with the patella and its correct movement during flexion and extension are referred to as patellar tracking disorders. In addition to patellar tracking disorders, a larger Q angle also can be a major factor in patellar subluxation or dislocation, as well as anterior cruciate ligament sprains.

There is an increased incidence of these knee disorders in women, The Q angle is greater in women due to the wider pelvis, which places the ASIS farther away from the patellar midline, thereby increasing the Q angle.

There are numerous causes of anterior knee pain. Several of these can be related to an excessive Q angle. It's not necessary to pull out the protractor and determine the exact Q angle. However, a visual estimation of the Q angle can give important clues about the role this postural distortion plays in a variety of pain complaints. That is why this study was undertaken to evaluate the relationship between the anterior knee pain and Q-angle.

What is Q angle: Three landmarks are needed to determine the Q-angle:

* Anterior Superior Iliac Spine (ASIS): The ASIS is the front of the pelvic bone that is felt in front of the hip at the level of your waist.

* Center of the Patella: The center of the patella is best identified by locating the top, bottom and each side of the patella, and then drawing intersecting lines.

* Tibial Tubercle: The tibial tubercle is the bump about 5 centimeters below the patella on the front of the shin bone (tibia).

The Q-angle is formed from a line drawn from the ASIS to the center of the patella, and from the center of the patella to the tibial tubercle. To find the Q-angle, measure that angle, and subtract from 180 degrees.

A normal Q-angle in men is 14 degrees and in women is 17 degrees.

[Instruments used to measure Q angle: Long arm goniometer (figure 3)

How Do You Measure The Q Angle?

The Q angle can be measured in laying or standing. Standing is usually more suitable, due to the normal weight-bearing forces being applied to the knee joint as occurs during daily activity.

Place the centre of the goniometer over the centre of the patella and position the bottom arm in line with the patella tendon and tibial tuberosity. Next position the upper arm so that it is pointed directly at the anterior inferior iliac spine (AIIS) of the ilium (point to which Rectus Femorisattaches). The small angle of the goniometer is the Q angle.

METHOD: This cross section study was performed on two groups:

One case group consisted of 50 outpatients (25men, and 25 women) aged between 15 and 35 years, with anterior knee pain.

Other control group consisted of 50 outpatients (25 men, and 25 women) with the same age distribution, who presented with different problems in the upper extremities and no knee problems. The Q-angle of each knee was measured in all participants, using a universal goniometer.

RESULTS: The mean Q-angle for men and women in the case group was 15.2 and 20.4 degrees, respectively. In the normal control group the angles were 12.3 and 15.9 respectively.

Table no.1 showing mean Q- angle of both males and females in both case and control groups.

All these differences were statistically significant.

A few similar studies have been previously performed with less noticeable values. Hand and Spalding reported that Q-angle measurement was a good predictor of patellofemoral pain syndrome. (6)

Tallay A in his epidemiological study could not identify any statistically significant intrinsic risk factors, although changes in the Q-angle might be related to an increased prevalence of patellofemoral pain syndrome. (7)

Herrington and Nester reported that any method that improved the reliability and applicability of Q-angle measurement could be useful in investigating the etiology and outcome of patellofemoral pain syndrome treatment. (8) Moreover, this study searched for the relationship between anterior knee pain and Q-angle, as an important concept in patellofemoral joint function.

CONCLUSION: These results substantiate the fact that patients with anterior knee pain have larger Q-angles than healthy individuals.


(1.) Busch MT. Sport Medicine. In: Lovell WW, Winter RB, Morrissy RT, Weinstein SL, eds. Lovell and Winter's Q-angle Pediatric Orthopedics. 5th ed. Philadelphia: Williams and Wilkins; 2001: 527- 557.

(2.) Sibley MB. Knee Injuries. In: Sato H, ed. Sport Injuries. 2nd ed. Philadelphia: Williams and Wilkins; 1994: 104-138.

(3.) McBeath AA. The patellofemoral joint. In: Evarts, C. McCollister, ed. Surgery of the Musculoskeletal System. 2nd ed. Churchill Livingstone. 1990: 456-486.

(4.) Phillips BB. Recurrent dislocations. In: Canale ST, Campbell WC, eds. Cambell's Operative Orthopedics. 8th ed. St. Louis: Mosby; 1998: 2587- 2614.

(5.) Horton MG, Hall TL. Quadriceps femoris muscle angle: normal values and relationships with gender and selected skeletal measures. PhysTher. 1989; 69: 897-901.

(6.) Hand CJ, Spalding TJ. Association between anatomical features and anterior knee pain in a "fit" service population.J R Nav Med Serv. 2004; 90: 125-134.

(7.) Tallay A, Kynsburg A, Toth S, Szendi P, Pavlik A, Balogh E, et al. Prevalence of patellofemoral pain syndrome. Evaluation of the role of biomechanical malalignments and the role of sport activity [Hungarian]. Orv Hetil. 2004; 145: 2093-2101.

(8.) Herrington L, Nester C. Q-angle undervalued? The relationship between Q-angle and mediolateral position of the patella. Clin Biomech (Bristol, Avon). 2004; 19: 1070-1073.

(9.) Caylor D, Fites R, Worrell TW.The relationship between quadriceps angle and anterior knee pain syndrome. J Orthop Sports Phys Ther. 1993; 17: 11- 16.

(10.) Insall J, Favlo DA, Wise DW. Chondromalacia patellae. A prospective study. J Bone Joint Surg Am. 1976; 58: 1-8.

(11.) Neely FG. Biomechanical risk factors for exercise-related lower limb injuries. Sports Med. 1998; 26: 395-413.

(12.) Insall J. "Chondromalacia patellae": patellar malalignment syndrome. Orthop Clin North Am. 1979;

(13.) Aglietti P, Insall JN, Cerulli G. Patellar pain and incongruence. Clin Orthop Relat Res. 1983; 176: 217- 224.

(14.) Hvid I, Andersen LI, Schmidt H. The relation to abnormal patellofemoral joint mechanics. Acta Orthop Scand. 1981; 52: 661-666.


[1.] Jyoti Agrawal

[2.] Leena Raichandani

[3.] Sushma K. Kataria

[4.] Surbhi Raichandani


[1.] M.Sc. Student, Department of Anatomy, Dr. S.N. Medical College, Jodhpur, Rajasthan.

[2.] Professor, Department of Anatomy, Department of Anatomy, Dr. S.N. Medical College, Jodhpur, Rajasthan.

[3.] Professor and H.O.D, Department of Anatomy, Department of Anatomy, Dr. S.N. Medical College, Jodhpur, Rajasthan.

[4.] M.B.B.S. Student, Department of Anatomy, Department of Anatomy, Dr. S.N. Medical College, Jodhpur, Rajasthan.


Dr.Jyoti Agrawal, W/o. Dr. I.K. Bansal, 1062, Sector--3, Huda Colony.

Date of Submission: 11/11/2013.

Date of Peer Review: 13/11/2013.

Date of Acceptance: 26/11/2013.

Date of Publishing: 23/12/2013

Table No. 1

Category        Men    Women

Case group      15.2   20.4
Control Group   12.3   15.9
COPYRIGHT 2013 Akshantala Enterprises Private Limited
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2013 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Agrawal, Jyoti; Raichandani, Leena; Kataria, Sushma K.; Raichandani, Surbhi
Publication:Journal of Evolution of Medical and Dental Sciences
Article Type:Clinical report
Geographic Code:9INDI
Date:Dec 23, 2013
Previous Article:Wunderlich's syndrome, an unusual cause of acute abdomen in tuberous sclerosis.
Next Article:Tornwaldt's cyst: an abnormal persistent remnant of notochord--a radiological study with embryological correlation.

Terms of use | Privacy policy | Copyright © 2022 Farlex, Inc. | Feedback | For webmasters |