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Year : 2023  |  Volume : 5  |  Issue : 1  |  Page : 102-107

Relationship between pelvic inclination and quadriceps angle in middle aged obese individuals

1 Department of Physiotherapy, School of Medical and Allied Sciences, G D Goenka University, Sohna Road, Gurugram, Haryana, India
2 Department of Cardiothoracic and Vascular Surgery, All India Institute of Medical Sciences, New Delhi, India

Date of Submission25-May-2022
Date of Decision02-Sep-2022
Date of Acceptance20-May-2023
Date of Web Publication11-Aug-2023

Correspondence Address:
Dr. Manish Kumar
Department of Physiotherapy, School of Medical and Allied Sciences, G D Goenka University, Sohna Road, Gurugram, Haryana
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijptr.ijptr_93_22

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Context: Many studies have engrossed on correlating one or two biomechanical parameters related to the lower limb alignment factors but not many have taken into account the effect of increased body weight on the relationship between Q-angle and pelvic tilt.
Aim: The present study aims to assess the changes in pelvic inclination angle (PIA) and quadriceps angle (Q-angle) in the different categories of body mass index (BMI). Furthermore, to find an association between PIA, Q-angle, and waist-hip ratio (WHR) in different categories of BMI.
Setting and Design: The Observational case control study was conducted on community dwelling individuals from Delhi NCR.
Subjects and Methods: Two hundred and forty participants (120 participants of BMI score 18.5–22.9 kg/m2 (normal weight healthy individuals) and 120 participants of BMI score >25 kg/m2 (obese healthy individuals) were recruited on the basis of inclusion and exclusion criteria. BMI, PIA, Q-angle, and WHR were assessed in the standing position.
Statistical Analysis: Intra-class correlations of analysis was done using the Pearson correlation coefficient calculation for all the measured variables.
Results: Significant higher mean values of PIA and Q-angle were observed in obese participants when compared with normal weight participants (P < 0.01). BMI was significantly positively correlated with PIA (P = 0.011) and Q-angle (P = 0.014) for obese population, whereas no significant association was found to normal weight healthy population. Similarly, statistically significant positive correlation was found between PIA and Q-angle (P < 0.01).
Conclusion: The study concluded that increase in body weight is an important factor which influences the biomechanical alignment of kinematic chain segments of the lower quadrant of the body. Hence, it is very important to focus on proper biomechanical alignment and the whole lower extremity should be considered rather than a single segment as a factor, because one mechanical factor has the potential to compensate for or affected by another when functioning in the weight bearing position.

Keywords: Body mass index, Pelvic inclination angle, Quadriceps angle, Waist-hip ratio

How to cite this article:
Kumar M, Arya P. Relationship between pelvic inclination and quadriceps angle in middle aged obese individuals. Indian J Phys Ther Res 2023;5:102-7

How to cite this URL:
Kumar M, Arya P. Relationship between pelvic inclination and quadriceps angle in middle aged obese individuals. Indian J Phys Ther Res [serial online] 2023 [cited 2023 Sep 27];5:102-7. Available from: https://www.ijptr.org/text.asp?2023/5/1/102/383685

  Introduction Top

Posture is the attitude for holding the body in upright position in standing, sitting, or lying down against the gravity. Adapted physiological curvatures of the spine help in maintaining erect standing posture and locomotion activities. Posture and its anomalies can be linked to different types of activities associated with mankind such as walking, running, squatting, etc., These can be affected by any abnormal changes in the body posture. The effect includes overstress on the spinal column including lower limbs. These stresses are not only influenced by body posture but also any hereditary or musculoskeletal dysfunction, psychological state of the individual, and the different types of forces acting on the spinal column along with the pelvis.[1]

The anatomic connection between the upper and lower quadrant of the musculoskeletal system is the pelvic girdle. This is responsible for the distribution of different forces between them. During the performance of activities in closed kinematic chain, the alignment of lower limb joints has the affect over the pelvic girdle position as reported by Eldesoky and Abutaleb.[2] They concluded that postural changes in the lower extremity may lead to the occurrence of biomechanical alterations in the pelvic girdle. Pelvic tilt is defined as “The angle between the horizontal plane and the perpendicular to the sacrum in the sagittal plane.” Normal range for male is around 13.8° ±4.5°, and females, it is 22.8° ±7.6°.[3] Previous studies have found that with increasing age, obesity, and lessened physical activity, there is a reduction in the performance of abdominal muscle, resulting in an increase of pelvic anterior tilt which is associated with an elevation in the lumbar lordosis while standing. Although Walker et al. inferred that in a standing position, there existed no relationship among lumbar lordosis, pelvic inclination and the force production by the abdominal muscle but advocated that both parameters that is lordotic curvature of lumbar region and inclination of the pelvis were presumably affected by a combination of several complex factors like age, sex, body mass index (BMI) and level of physical activity.[4],[5]

The quadriceps angle (Q-angle) is defined as “The acute angle formed between the vectors for combined angle of pull of the four parts of quadriceps femoris muscle and the patellar tendon.”[6] In the frontal plane when the knee is in extended position, Q-angle measurement gives a rational evaluation of the resultant force production amidst the quadriceps muscle group and the patellar tendon. Q angle normally fall between 12° and 20° where males are at lower end of this range value and females likely have higher values.[7],[8] It has been advocated that the Q angle is a combined measure of the position of the pelvis, rotation at hip, tibial rotation, location of patella, and foot alignment.[9] Powers did a study to provide a theoretical overview of how altered lower-extremity kinematics may influence the patellofemoral joint. They concluded that Q angle may rise due to increase in anterior pelvic tilt. With anterior pelvic tilt there is excessive posterior orientation of the acetabulum that lead to more internal rotation of the femur, displacing the patella medially and positioning the tibial tuberosity more laterally.[10]

Nguyen et al. investigated the relationship between the Q-angle and lower extremity alignment in healthy college-going participants and establish a relationship between the Q-angle, increased tibiofemoral angle, and increased femoral anteversion but not with pelvic angle.[11] These findings point out the gap in knowledge existing regarding exploring this relationship in overweight subjects.

Sedentary lifestyles, food habits, high stress levels with high content of fat, and calories intake lead to increase in BMI. With aging, there is a reduction in muscle mass and metabolism that may lead to gain in the body weight. BMI and waist-hip ratio (WHR) are indices to measure obesity. High BMI can be linked with increase fat around the belly lading to weak abdominal muscles and in turn causing increase lordosis in the lower back posture. This leads to alteration in passing of line of the gravity and transfer of force through knee and foot.[12],[13]

The impact of overweight on relationship between pelvic inclination angle (PIA) and Q angle could give an insight into the controversial association between low back pain and overweight and obesity. Furthermore, it may shed more light on the role of pelvic alignment in the management of overweight knee osteoarthritis (OA) patients. A study done by Prakash et al. to realize the association among BMI and Q-Angle in patients having primary OA knee. It clinically indicates that when body weight increases, the knee joint is subjected to more axial loading causing more lateral pull of patella due to the changes in Q-angle and increasing the risk of knee OA.[14] Many studies have engrossed on correlating one or two biomechanical parameters related to the lower limb alignment factors but not many have taken into account the effect of increased body weight on the relationship between Q-angle and pelvic tilt. Hence, attributing to the paucity of literature our study aims to assess the relationship between PIA and Q angle and effect of increasing body weight on them.

  Subjects and Methods Top

The sample size was calculated using the nMaster 2.0 software, (Department of Biostatistics, CMC, Vellore, India). The power of the study was taken to be 80% and confidence interval of 95% was taken. The sample size calculation was done as per the article by Raizada et al.[8] The sample size was estimated to be a minimum of 28 per group. as shown in [Table 1].
Table 1: Sample size calculation

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A total of 240 participants (120 normal weight (18.5–22.9 kg/m2) of mean age of 39.82 ± 7.15 years and 120 obese (>25 kg/m2) of 38.65 ± 6.10 years, but otherwise healthy individuals (according to Asian and South Asian classification of BMI) as shown in [Table 2] were recruited from Delhi-NCR region, India[15].
Table 2: Classification of BMI

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They were included with aged between 30 and 50 years, both male and female and subjects belonging to BMI category: 18.5–22.9 kg/m2 (normal weight) and >25 kg/m2 (obese). Participants were excluded due to a history of surgical intervention for lower limb and spinal pathology, presence of observable spinal deformities, and lower limb deformities such as scoliosis, kyphosis, genu valgum, genu varum, rigid flat foot, claw foot, patella alta, patella baja, and any malunion of lower limb fractures and presence of any leg length discrepancy.

Outcome measures taken were PIA, Q-angle, WHR, and BMI. Those fulfilling the criteria were explained in detail about the study and a written informed consent was obtained from the subjects willing to participate. Pelvic tilt and Q-angle were done by the use of gravity inclinometer with magnetic base and goniometer method in standing, respectively, for all the subjects in two groups. The weight and height were measured for all the subjects. BMI was calculated as BMI = wt/ht where, weight in kg and height in m2.

PIA was measured using the magnetic pelvic inclinometer. Magnetic pelvic inclinometer, hand held instrument was designed to measure pelvic bone inclination (B018 LJVE9M, Gilhot, India). The subject was asked to stand on a level surface with feet placed 6 inches apart. The rectangular platform was placed on the spinous process of S1 to form a tangent to it. The angle of the tangent with respect to the vertical plane then was read from the inclinometer. The value of PIA was recorded as subtraction of the recorded values with 90. Three readings were taken with interval of 2 min between the readings. Mean of three values was used for analysis. The measurement of PIA using magnetic pelvic inclinometer showed excellent validity and reliability.[16]

Q-angle was measured using a standard full circle goniometer made of clear plastic material. The angles were measured for the right and left lower limb in a standing position and mean of two measurements were estimated for all the subjects. The anterior superior iliac spine (ASIS), tibial tuberosity, and assessed midpoint of the patella were palpated and marked prior to measurement with the help of removable adhesive stickers. The fulcrum of the goniometer was positioned over the patellar midpoint with the bottom arm directed towards tibial tuberosity and the upper arm was aligned in line toward the ASIS. The small angle formed between them on the goniometer then assessed as Q-angle.[8],[17] Goniometer method of measuring Q-angle is a reliable tool with good intrarter and interrater reliability (intraclass correlation coefficient = 0.90–0.94).[18]

WHO defines “Waist–hip ratio or waist-to-hip ratio (WHR) is the ratio of the circumference of the waist to that of the hip. This was calculated as waist measurement divided by hip measurement (W/H).” The measurement was done with inch tape.[8]

Statistical analysis

Statistical data analysis was done using the Statistical Package for the Social Sciences (SPSS) version 25 (International Bussiness Machine (IBM), US). Descriptive statistics was used to analyze and find out the mean and standard deviation of demographic profile and selected outcome measures of the subjects. P values were generated for group differences using independent two sample t-test for between the groups. Intra-class correlations of analysis end points for normal weight and overweight groups were done using the Pearson correlation coefficient calculation for all the measured variables.

[TAG:2]Results [/TAG:2]

Demographic profile of study participants of both the groups is presented in [Table 3].
Table 3: Demographic characteristics of the study participants in Group A and Group B

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The demographic profile of the study participants depicted that the mean age of normal weight and obese group was 39.82 ± 7.15 and 38.65 ± 6.10 years, respectively, with statistical insignificant mean difference of 1.17 (t (238) =1.36 at P = 0.17) using independent t-test. Data constituted almost equal number of males and females in Group A (males 50% and females 50%) and Group B (males 52.5% and females 47.5%). There was statistically insignificant difference between both the groups (P = 0.69).

The anthropometric parameters of study participants of both the groups are depicted in [Table 4]. The mean weight (kg), height (cm), BMI (kg/m2), waist circumference (cm), hip circumference (cm), and WHR were compared between normal weight subjects (Group A) and obese subjects (Group B) using the independent t-test. The mean weight and BMI were significantly higher among obese subjects in comparison to normal weight subjects (t (238) = −15.26, P < 0.01 and t (238) = −25.79, P < 0.01). The mean waist circumference and WHR were also significantly higher among obese subjects in comparison to normal weight subjects (t (238) = −3.36, P < 0.01 and t (238) = −12.77, P < 0.01). Whereas, the mean height and hip circumference were significantly higher among normal weight subjects in comparison to obese subjects (t (238) =3.99, P < 0.01) and t (238) =5.83, P < 0.01).
Table 4: Mean difference of anthropometric parameters between Group A and Group B

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The mean PIA and Q-angle (left, right and mean) of the study participants of both the groups are depicted in [Table 5]. The mean PIA and Q-angle-mean were significantly higher among obese subjects in comparison to normal weight subjects (t (238) = −6.19, P < 0.01, t (238) = −6.65, P < 0.01 and t (238) = −18.63, P < 0.01) respectively, showing the effect of increased weight on these parameters.
Table 5: Mean difference of pelvic inclination angle, navicular drop test, and quadriceps-angle between Group A and Group B

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The correlation of outcome variables (PIA, Mean Q-angle, BMI, and WHR) for normal weight group is depicted in [Table 6]. There was an insignificant correlation of WHR with PIA, Mean Q-angle and BMI. There was insignificant correlation of PIA with Mean Q-angle, and BMI and also insignificant correlation found between BMI and Mean Q-angle in normal weight group.
Table 6: Correlation of outcome variables for normal weight group

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The correlation of outcome variables (PIA, Mean Q-angle, BMI, and WHR) in obese group is depicted in [Table 7]. BMI was significantly positively correlated with PIA (r = 0.23, P = 0.011) and Mean Q-angle (r = 0.22, P = 0.014). A statistically significant positive correlation found between PIA and Mean Q-angle (r = 0.48, P < 0.01). There was insignificant correlation of WHR with Mean Q-angle, PIA, and BMI in obese group.
Table 7: Correlation of outcome variables for obese group

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  Discussion Top

Our lower limbs are a part of a long kinematic chain, thus interlinked and interdependent in terms of movements and alignments. Therefore, if normal mechanics of various lower limb segments is interdependent, the malalignment should also be. It is postulated that changes in PIA bring about changes in Q-angle by means of biomechanical changes such as excessive posterior shifting of acetabulum, medial torsion of femur, and compensatory lateral torsion of tibia. Various studies in past have tried to investigate this relationship and a few have been able to confirm it while others haven't. Khamis and Yizhar have stated that with excessive anterior pelvic tilt, acetabulum shifts backward causing the femur to internally rotate on pelvis so that femoral head has proper acetabular coverage. This could be a major reason for increase in Q-Angle value with increasing pelvic tilt.[19] The above mentioned mechanism was recommended by Powers through a study on the influence of altered lower extremity kinematics on patellofemoral joint dysfunction.[10]

In contrast to the above studies, Nguyen et al.[11] done a study on the relationship between lower extremity alignment and the Q-angle and pointed out that frontal plane landmarks, which are used to measure Q-angle, consists of center point of patella and tibial tuberosity, may not be sufficiently deviated by increase in both anterior pelvic tilt and navicular drop that lead to rotational alteration in the femur and tibia and may displace the patella and tibial tuberosity medially and laterally respectively. Another reason for not getting any correlation in their study could be the young age of subjects i.e. college-going students where mean weight was 80.8 ± 13 kg in males and 63.4 ± 12.4 kgs in females. Similarly, in normal weight subjects of the current study, the same reason could be responsible for insignificant correlation between PIA and Q angle because our subjects also had a mean weight of 60.5 ± 7.2 kgs. Increase in body weight, in turn, BMI is expected to increase both pelvic inclination and Q-Angle independently.

Another study done by Onyemaechi et al.[20] found positive correlation among lumboscaral angle, BMI, and WHR. Significantly increased lumbo-sacral angle (LSA) was found in subjects with rise BMI and WHR in comparison to the subjects having standard BMI and WHR. Handini[21] also found increase lumbar curvature with increase BMI in females. The authors explicated that with increase in weight specifically in subjects with more truncal obesity; LSA was increased due to anterior displacement of sacrum base by the raised weight of the trunk. Raizada et al.[8] in their study have found higher values of Q angle in both males and females with increased weight, waist and hip circumference, which can be due to high body fat in lower body area. Although BMI assesses general obesity and indicator of overall adiposity, WHR is used to estimate the distribution of body fat and is indicator for abdominal adiposity and measures central (truncal) obesity.[22] Prakash et al.[14] also showed in their study that there is significant positive correlation between BMI and Q-angle where as insignificant association among BMI, WHR, and Q-angle and is in line with our findings. They concluded that BMI and WHR can be interdependent risk factors for primary OA knee that indicates if body fat increases due to increase in WHR, there can be increment in BMI also and heightened BMI result in raised Q-angle, which is ultimately a potential and direct risk factor for primary OA knee.

Increasing weight by means of increasing abdominal obesity leads to weak abdominal wall and muscles, leading to excessive anterior pelvic tilt and more femoral internal torsion. This leads to medial shift of weight arm and normal reaction force vector and increasing the medial angulation of distal femur lead to increase in Q angle. Thus, it was postulated that a higher and more significant correlation between pelvic inclination and Q angle in obese adults and findings of the present study were in support of this postulation.

  Conclusion Top

Changes in PIA bring about the changes in Q-angle by means of biomechanical variations as the segments of lower limb kinematic chain are interlinked and interdependent. In addition, increase in weight causes more changes in pelvic inclination and Q-angle. This implies that as the BMI increases, the relationship between lower limb kinematic segments gets stronger, thus, pathology at one joint would very likely give rise to pathology at other joints.


Both the authors were involved in concept/design. Additionally, PA conducted the data analysis. All authors conducted the study, drafted, and reviewed and approved the final version of the manuscript.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Borges Cdos S, Fernandes LF, Bertoncello D. Relationship between lumbar changes and modifications in the plantar arch in women with low back pain. Acta Ortop Bras 2013;21:135-8.  Back to cited text no. 1
Eldesoky MT, Abutaleb EE. Influence of bilateral and unilateral flatfoot on pelvic alignment. Int J Med Health Sci 2015;9:641-5.  Back to cited text no. 2
Burdett RG, Brown KE, Fall MP. Reliability and validity of four instruments for measuring lumbar spine and pelvic positions. Phys Ther 1986;66:677-84.  Back to cited text no. 3
Walker ML, Rothstein JM, Finucane SD, Lamb RL. Relationships between lumbar lordosis, pelvic tilt, and abdominal muscle performance. Phys Ther 1987;67:512-6.  Back to cited text no. 4
Youdas JW, Garrett TR, Harmsen S, Suman VJ, Carey JR. Lumbar lordosis and pelvic inclination of asymptomatic adults. Phys Ther 1996;76:1066-81.  Back to cited text no. 5
Omololu BB, Ogunlade OS, Gopaldasani VK. Normal Q-angle in an adult Nigerian population. Clin Orthop Relat Res 2009;467:2073-6.  Back to cited text no. 6
Emami MJ, Ghahramani MH, Abdinejad F, Namazi H. Q-angle: An invaluable parameter for evaluation of anterior knee pain. Arch Iran Med 2007;10:24-6.  Back to cited text no. 7
Raizada A, Shruthy KM, Takiar R, Bhuvanesh S. Changes in quadriceps angle (Q-angle) with regard to gender and different anthropometric parameters. Int J Anat Res 2019;7:6756-61.  Back to cited text no. 8
Hruska R. Pelvic stability influences lower-extremity kinematics. Biomechanics 1998;6:23-9.  Back to cited text no. 9
Powers CM. The influence of altered lower-extremity kinematics on patellofemoral joint dysfunction: A theoretical perspective. J Orthop Sports Phys Ther 2003;33:639-46.  Back to cited text no. 10
Nguyen AD, Boling MC, Levine B, Shultz SJ. Relationships between lower extremity alignment and the quadriceps angle. Clin J Sport Med 2009;19:201-6.  Back to cited text no. 11
Cibulka MT. Low Back pain and its relation to the hip and foot. J Orthop Sports Phys Ther 1999;29:595-601.  Back to cited text no. 12
Chougala A, Phanse V, Khanna E, Panda S. Screening of body mass index and functional flatfoot in adult: An observational study. Int J Physiother Res 2015;3:1037-41.  Back to cited text no. 13
Prakash V, Sahay P, Satapathy A. Correlation between body mass index, waist hip ratio & quadriceps angle in subjects with primary osteoarthritic knee. Int J Health Sci Res 2017;7:197-205.  Back to cited text no. 14
Weir CB. Jan A. BMI classification percentile and cut off points. StatPearls: Treasure Island, FL, USA. 2021. p. 1-4.  Back to cited text no. 15
Youdas JW, Garrett TR, Egan KS, Therneau TM. Lumbar lordosis and pelvic inclination in adults with chronic low back pain. Phys Ther 2000;80:261-75.  Back to cited text no. 16
Türkmen F, Acar MA, Kacıra BK, Korucu İH, Erkoçak ÖF, Yolcu B, et al. A new diagnostic parameter for patellofemoral pain. Int J Clin Exp Med 2015;8:11563-6.  Back to cited text no. 17
Ferro ES. Reliability and validity of an electronic inclinometer (EI) and standard goniometer (SG) for measuring the Q-angle in 2 different positions in a sample of women. Int J Exerc Sci Conf Proc 2010;2:4.  Back to cited text no. 18
Khamis S, Yizhar Z. Effect of feet hyperpronation on pelvic alignment in a standing position. Gait Posture 2007;25:127-34.  Back to cited text no. 19
Onyemaechi NO, Anyanwu GE, Obikili EN, Onwuasoigwe O, Nwankwo OE. Impact of overweight and obesity on the musculoskeletal system using lumbosacral angles. Patient Prefer Adherence 2016;10:291-6.  Back to cited text no. 20
Handini L. Correlation analysis between women's body mass index and mechanical low back pain. Indian Journal of Forensic Medicine and Toxicology 2020;14:1995-9.  Back to cited text no. 21
Resubun DS, Melaniani S, Nugraheni N, Subadi I. Relationship between body mass index, type of weight bearing activity and beighton and horan joint mobility index with pes planus in adult athletes. International Journal of Research Publications 2022;94:120-30.  Back to cited text no. 22


  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]


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