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 Table of Contents  
Year : 2022  |  Volume : 16  |  Issue : 1  |  Page : 28-32

Correlation between presence of Lumbar Instability, Physical function and Balance in subjects with knee osteoarthritis: An observational Study

1 PhD Scholar at Gujarat University and Associate Professor in Musculoskeletal Department of C U Shah Physiotherapy College, Saurashtra University, Surendranagar, Gujarat, India
2 PhD (Physiotherapy), Senior Lecturer, Government Physiotherapy College, Ahmedabad, Gujarat, India

Date of Submission14-Jun-2021
Date of Decision16-May-2022
Date of Acceptance17-May-2022
Date of Web Publication22-Jul-2022

Correspondence Address:
Dr. Urmi Bhatt
“Madhav”, Street No. 6, Behind Nilkanth Mahadev Mandir, Joravarnagar, Surendranagar, Gujarat
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/pjiap.pjiap_11_21

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BACKGROUND AND OBJECTIVES: Osteoarthritis (OA) of the knee is one of the most common musculoskeletal disorders that increase the global health burden. Various research aimed to improve pain and physical functions in individuals with OA knee have been conducted. However, there is a dearth of research evaluating coexisting lumbar instability and its impact on physical function limitation and risk of fall in individuals with knee OA, while there is a pool of research on kinetic chain evaluation including lumbar spine for the athletic population for injury prevention.
METHODOLOGY: Twenty-two individuals with OA knee, aged 50–65 years (male or female) willing to participate in the study were included in the study. Demographic details including age, body mass index (BMI), and duration of knee pain were recorded. All the individuals were screened for the presence of lumbar segmental instability (using passive lumbar extension test), balance (using Dynamic Gait Index), and physical function using mWOMAC.
RESULTS: Data were analyzed using SPSS. There were significantly greater (P < 0.05) deficits in balance and function of individuals with the presence of clinical lumbar segmental instability. In addition, BMI and duration of knee pain also correlated positively with balance and function deficits in all individuals.
CONCLUSION: The presence of lumbar segmental instability in individuals with OA knee puts them at greater risk of falls due to altered balance and limits functional ability as well.

Keywords: Balance, knee osteoarthritis, lumbar instability, physical function

How to cite this article:
Bhatt U, Shukla Y. Correlation between presence of Lumbar Instability, Physical function and Balance in subjects with knee osteoarthritis: An observational Study. Physiother - J Indian Assoc Physiother 2022;16:28-32

How to cite this URL:
Bhatt U, Shukla Y. Correlation between presence of Lumbar Instability, Physical function and Balance in subjects with knee osteoarthritis: An observational Study. Physiother - J Indian Assoc Physiother [serial online] 2022 [cited 2023 Mar 21];16:28-32. Available from: https://www.pjiap.org/text.asp?2022/16/1/28/351859

  Introduction Top

Osteoarthritis (OA) is a degenerative musculoskeletal disorder that commonly affects weight-bearing joints of the lower limb, especially the hip and knee joints. OA is characterized by pain, stiffness, and loss of normal joint function due to progressive cartilage destruction, osteophyte formation, and joint inflammation. OA of the knee is a leading cause of pain and locomotor disability in the elderly population.[1]

Nonsurgical management of knee OA as recommended by OA Research Society International includes biomechanical intervention, patient education, strength training, and weight management as the most appropriate therapy to manage the symptoms of knee OA.[2]

Most individuals with knee OA manage locomotive activities by compensatory changes in gait, posture, and transfer activities.[3] These adaptations appear to reduce the loading of painful arthritic limb and allows the individual to cope with activities of daily living.[4] At the same time, these adaptations, appear to increase the mechanical cost of ambulation, fall risk, and loading of the proximal joints.[5]

Individuals with knee OA frequently suffer from chronic low back pain, which seems to be secondary to adaptive changes in locomotive activities. Any chronic low back pain, without an obvious history of trauma or exact cause, is frequently caused by underlying segmental instability.[6],[7] Lumbar segmental instability, mechanical or functional has been shown to be an important risk factor for injury and predictor of poor performance in various sports populations.[8],[9]

The aim of the present study is to see the impact of lumbar instability on physical function and balance in individuals with knee OA.

  Methodology Top

The study was conducted at the institutional musculoskeletal physiotherapy department after obtaining ethical approval. Twenty-two individuals with knee OA, within the age group of 50–65 years (male or female), willing to participate in the study were included in the study based on the selection criteria. Individuals were not included in the study, if they had any neurological or cardiac problems and history of trauma to the spine or lower limbs, visual or hearing impairments, and a history of falls in the past 1 year. Written informed consent was taken from all the individuals before obtaining any data. Demographic details including age, body mass index (BMI), and duration of knee pain (in months) were recorded.

Afterward, all the individuals were screened for the presence of low back pain and the presence of segmental instability (using a passive lumbar extension test). For the passive lumbar extension test, the patient is placed in the prone lying position. The therapist elevates the patient's legs to a height of approximately 30 cm without bending the knees. If the patient complains of pain in the low back region during the test, it is considered positive and indicates the presence of lumbar segmental instability.[10]

Based on the presence or absence of lumbar instability (positive or negative passive lumbar extension test), individuals were divided into two groups: Group A (n = 10, without instability) and Group B (n = 12, with instability).

Afterward, an assessment of levels of pain using the Numerical Pain Rating Scale (NPRS) and physical function was done using the modified Western Ontario and McMaster Universities Arthritis Index (mWOMAC) in all the individuals of both groups. Modified WOMAC is a self-administered questionnaire, that comprises 24 questions divided into three subscales: Pain (five items), stiffness (two items), and physical function (17 items). Each question is scored on a scale of 0–4, which corresponds to none (0), mild (1), moderate (2), severe (3), and extreme (4). The mWOMAC takes <10 min to complete and can be taken on paper or over the telephone or computer. Higher the scores on mWOMAC, worse the pain and functional limitations.[11]

Assessment of balance was done using the Dynamic Gait Index (DGI) in all the individuals of both groups. The DGI tests, the ability of the participant to maintain balance while walking and respond to different tasks during walking, throughout the test. Participants are asked to walk on a 10 m walkway with eight different tasks. The eight items are: walking on level surfaces, altering speeds, head turns in horizontal and vertical directions, walking and turning 180° to stop, stepping over and around obstacles, and stair ascent and descent. Each of these tasks is scored on a scale of 0–3, where 3 indicates normal performance and 0 indicates severe impairment. The test takes approximately 15 min to complete.[12]

  Results Top

Data were analyzed using the Statistical Package for the Social Sciences (SPSS) software version 20 (IBM SPSS statistics for windows, version 20, N.Y., USA). The data were screened for the presence of normal distribution, before applying any statistical tests. The confidence interval was 95% and the level of significance was kept at 5% for all the tests. [Table 1] shows the demographic details and characteristics of all participants. Both the groups were compared for age, BMI, and duration of knee pain to see if the data were equally distributed in both groups or not. BMI and duration of knee pain (in months) of both the groups were compared using unpaired t-tests, while pain levels (NPRS) were compared using Mann–Whitney U-test [Table 2]. Modified WOMAC and DGI scores of both the groups were compared using unpaired t-tests [Table 2]. There were significantly greater (P < 0.05) deficits in balance and function of individuals with the presence of clinical lumbar segmental instability. A correlational analysis was made between BMI, levels of pain, duration of knee pain, and physical function and balance [Table 3]. Pearson correlation test was used to analyze the relationship between all the variables, except for NPRS. Duration of knee pain correlated moderately, yet significantly with mWOMAC (r = 0.45, P < 0.05), and no correlation was found between duration of knee pain and DGI. NPRS correlated moderately, yet significantly with DGI (r = 0.41, P < 0.05), and no correlation was found between NPRS and mWOMAC.
Table 1: Demographic details of participants

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Table 2: Tests and their interpretation

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Table 3: Correlation between body mass index, duration of knee pain, Numerical Pain Rating Scale, and Modified Western Ontario and McMaster Universities Arthritis Index and DGI

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  Discussion Top

The results of the present study indicate significant impairments in physical function and balance in knee OA participants with lumbar segmental instability as compared to those without lumbar instability. The study found a moderate yet significant correlation between BMI and physical function as well as balance in knee OA participants. The study also showed a moderate yet significant correlation between pain levels and balance, which is in accordance with previous researches. The study also found a moderate correlation between the duration of symptoms and physical function.

The correlation between higher BMI and physical functions and balance can be explained by the effect of obesity on overall health of an individual. Various researches have linked higher BMI with poor physical function and balance in the knee OA population.[13] Higher BMI may cause increased mechanical loading of all the joints, including the knee joint, as well as it accelerates the inflammatory process due to altered metabolism.[14] Obesity causes forward shifting of the center of gravity and challenges balance further. This increases the mechanical cost of daily living activities and further increases the loading of lower limb joints and leads to greater difficulty in marinating balance and loss of physical function.

The study also showed a moderate yet significant correlation between pain levels and balance, which is in accordance with previous researches.[15] According to a study by Docyung and others,[15] a more painful knee is associated with weaker quadriceps, reduced lower limb function, and reduced balance. Pain can cause reflex inhibition of quadriceps muscle and thereby may alter with the locking mechanism of the knee. A deficient locking mechanism of the knee may predispose an individual to frequent falls due to loss of balance. Hence, although arthritic knee pain is chronic in nature and has behavioral components, it is an important symptom that can interfere with the balance of the elderly and must be addressed adequately during rehabilitation.

The correlation between the duration of symptoms and physical function can be explained by the degenerative nature of the disease. As the disease duration increases, it leads to progressive deficits in muscle strength and joint function, which can adversely affect the functional status of the individual.

Significantly greater deficits in balance and physical function in subjects with knee OA with lumbar segmental instability can be explained by a direct mechanical link between the spine and the lower extremities.

The lumbar spine and pelvis serve as a stable proximal base around which both the lower limbs swing like a pendulum during normal level walking. If the proximal segment is not rigid and shakes easily upon weight shifts, it will increase energy consumption during day-to-day activities and this, in turn, will challenge the balance as well.[16]

A stable and ergonomic upright standing position in ambulatory humans is achieved by intricate alignment of the spine, pelvis, and lower extremity. Pathology in any one or more segments can disturb global postural alignment, resulting in a mandatory change in alignment at other segments to maintain the equilibrium [Figure 1].[17] Altered spinal alignment has been shown to be linked with balance deficits in the elderly as well as middle-aged population.[18]
Figure 1: Cascade of degeneration: from knee to spine via alterations in gait

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Restriction of knee extension in people with knee OA has been linked with altered lumbar lordosis. This change in lumbar alignment due to knee pathology is referred to as “knee-spine syndrome” by Yasuaki Murata and others.[19]

The finding of the current study is in accordance with numerous previous research that has identified lumbar segmental instability as an important cause of injury in the young athletic population. Lumbar segmental stability has been shown to be linked with lower extremity function and injury secondary to loss of balance in various populations. Lumbar segmental stability or core stability is the ability of the lumbopelvic hip complex to prevent buckling and to sustain equilibrium after perturbation. The lumbopelvic complex also provides a feedforward control to prepare for upper or lower limb moment productions.[20],[21] Hence, identifying and addressing lumbar segmental instability in OA knee individuals is very important to improve function and balance.

  Conclusion Top

The present study indicates greater deficits in balance and limitations in physical function in OA knee individuals with lumbar instability. Future studies addressing lumbar segmental instability can give meaningful insight into the rehabilitation of OA knee individuals. The findings of the study also indicate that higher BMI, higher pain levels, and higher duration of symptoms can be contributors to reduced physical function and altered balance in OA knee individuals.


The authors are greatly thankful to all the participants for their enthusiasm and valuable time for the study and to the management of C. U. Shah Physiotherapy College, Surendranagar, for their constant support and keen interest in research activities.

Financial support and sponsorship

This study was financially supported by Musculoskeletal physiotherapy OPD of C. U. Shah Physiotherapy College.

Conflicts of interest

There are no conflicts of interest.

  References Top

Kloppenburg M, Berenbaum F. Osteoarthritis year in review 2019: Epidemiology and therapy. Osteoarthritis Cartilage 2020;28:242-8.  Back to cited text no. 1
Bannuru RR, Osani MC, Vaysbrot EE, Arden NK, Bennell K, Bierma-Zeinstra SM, et al. OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. Osteoarthritis Cartilage 2019;27:1578-89.  Back to cited text no. 2
Mills K, Hunt MA, Ferber R. Biomechanical deviations during level walking associated with knee osteoarthritis: A systematic review and meta-analysis. Arthritis Care Res (Hoboken) 2013;65:1643-65.  Back to cited text no. 3
Metcalfe AJ, Stewart C, Postans N, Dodds AL, Holt CA, Roberts AP. The effect of osteoarthritis of the knee on the biomechanics of other joints in the lower limbs. Bone Joint J 2013;95-B: 348-53.  Back to cited text no. 4
Bowd J, Biggs P, Holt C, Whatling G. Does gait retraining have the potential to reduce medial compartmental loading in individuals with knee osteoarthritis while not adversely affecting the other lower limb joints? A systematic review. Arch Rehabil Res Clin Transl 2019;1:100022.  Back to cited text no. 5
Rahbar M, Shimia M, Toopchizadeh V, Abed M. Association between knee pain and low back pain. J Pak Med Assoc 2015;65:626-31.  Back to cited text no. 6
Demoulin C, Distrée V, Tomasella M, Crielaard JM, Vanderthommen M. Lumbar functional instability: A critical appraisal of the literature. Ann Readapt Med Phys 2007;50:677-84, 669-76.  Back to cited text no. 7
McGill SM. Low back stability: From formal description to issues for performance and rehabilitation. Exerc Sport Sci Rev 2001;29:26-31.  Back to cited text no. 8
Leetun DT, Ireland ML, Willson JD, Ballantyne BT, Davis IM. Core stability measures as risk factors for lower extremity injury in athletes. Med Sci Sports Exerc 2004;36:926-34.  Back to cited text no. 9
Ferrari S, Manni T, Bonetti F, Villafañe JH, Vanti C. A literature review of clinical tests for lumbar instability in low back pain: Validity and applicability in clinical practice. Chiropr Man Therap 2015;23:14.  Back to cited text no. 10
Khuman R, Chavda D, Surbala L, Bhatt U. Reliability and validity of modified western Ontario and McMaster universities osteoarthritis index Gujarati version in participants with knee osteoarthritis. Physiotherapy 2018;12:8.  Back to cited text no. 11
Herman T, Inbar-Borovsky N, Brozgol M, Giladi N, Hausdorff JM. The Dynamic Gait Index in healthy older adults: The role of stair climbing, fear of falling and gender. Gait Posture 2009;29:237-41.  Back to cited text no. 12
Wluka AE, Lombard CB, Cicuttini FM. Tackling obesity in knee osteoarthritis. Nat Rev Rheumatol 2013;9:225-35.  Back to cited text no. 13
Sowers MR, Karvonen-Gutierrez CA. The evolving role of obesity in knee osteoarthritis. Curr Opin Rheumatol 2010;22:533-7.  Back to cited text no. 14
Kim D, Park G, Kuo LT, Park W. The effects of pain on quadriceps strength, joint proprioception and dynamic balance among women aged 65 to 75 years with knee osteoarthritis. BMC Geriatr 2018;18:245.  Back to cited text no. 15
Akuthota V, Nadler SF. Core strengthening. Arch Phys Med Rehabil 2004;85:S86-92.  Back to cited text no. 16
Wang WJ, Liu F, Zhu YW, Sun MH, Qiu Y, Weng WJ. Sagittal alignment of the spine-pelvis-lower extremity axis in patients with severe knee osteoarthritis: A radiographic study. Bone Joint Res 2016;5:198-205.  Back to cited text no. 17
Imagama S, Ito Z, Wakao N, Seki T, Hirano K, Muramoto A, et al. Influence of spinal sagittal alignment, body balance, muscle strength, and physical ability on falling of middle-aged and elderly males. Eur Spine J 2013;22:1346-53.  Back to cited text no. 18
Murata Y, Takahashi K, Yamagata M, Hanaoka E, Moriya H. The knee-spine syndrome. Association between lumbar lordosis and extension of the knee. J Bone Joint Surg Br 2003;85:95-9.  Back to cited text no. 19
Willson JD, Dougherty CP, Ireland ML, Davis IM. Core stability and its relationship to lower extremity function and injury. J Am Assoc Orthop Surg 2005;13:316-25.  Back to cited text no. 20
Jull GA, Richardson CA. Rehabilitation of active stabilization of the lumbar spine. In: Twomy LT, Taylor JR, editors. Physical Therapy of the Lumbar Spine. 2nd ed. New York: Churchill Livingstone; 1994.  Back to cited text no. 21


  [Figure 1]

  [Table 1], [Table 2], [Table 3]


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