7/31/2019 mjms-18-2-040

1/7

www.mjms.usm.my Penerbit Universiti Sains Malaysia, 2011For permission, please email:mjms.usm@gmail.com

Abstract

Background:Knee proprioception is compromised in knee osteoarthritis. There are severalways of measuring proprioceptive acuity, but there is lack of consensus over the ideal testingposition. The study aimed to evaluate the inuence of 2 testing positions (sitting versus prone lying)on proprioceptive knee assessment score in patients with early knee osteoarthritis.

Methods:The study included 70 subjects who came to the Out-Patient Department with adiagnosis of early knee osteoarthritis. The subjects were assessed for their proprioceptive acuityscores in both the test positions at 30 and 60 of knee exion using proprioceptive knee assessmentdevice. They were asked to perform 5 trials in both testing positions with appropriate rest intervals.After initial assessment, the subjects were randomly allocated among group 1 and group 2. Treatmentimplementation was done for 8 weeks followed by re-evaluation: group 1 received context-specicproprioceptive retraining along with multijoint coupling strategies and group 2, conventionaltreatment.

Results: The subjects were compared using difference of pre- and post-treatmentproprioceptive acuity scores. The difference of proprioceptive acuity impairment scores of the leftknee at 30 and 60, and the right knee at 60 in prone lying position were statistically signicant,withPvalue ranging from less than 0.001 to 0.028.

Conclusion: It was found that the prone lying testing position was more sensitive than sittingposition for assessing proprioceptive acuity for knee osteoarthritis.

Keywords:adaptive behavior, knee, patient positioning, proprioception, osteoarthritis

Original Article Inuence of Sitting and Prone Lying Positionson Proprioceptive Knee Assessment Score inEarly Knee Osteoarthritis

VijayBatra1

, Vijai Prakash Sharma1

, Meenakshi Batra1

,Girdhar Gopal agarwal2, Vineet Sharma3

1 Department of Physical Medicine and Rehabilitation, Rehabilitation andArticial Limb Centre, Chhatrapati Shahuji Maharaj Medical University(Formerly King George Medical University), Dali Ganj Bridge, Nabiullah Road,

Lucknow: 226018, Uttar Pradesh, India

2 Department of Statistics, Lucknow University, Lucknow:226 007, India

3 Department of Orthopaedics, Chhatrapati Shahuji Maharaj MedicalUniversity (Formerly King George Medical University), Dali Ganj Bridge,

Nabiullah Road, Lucknow: 226018, Uttar Pradesh, India

Submitted:9 Mar 2010Accepted:28 Aug 2010

IntroductionProprioception is the sense of position and

movement of the limbs, and it is the result ofsensory inputs arising from muscle, skin, andjoint structures (1). It can also be dened as theconscious and unconscious awareness of bodyposition, movement, and forces acting on thebody, for which accurate sensory input and centralintegration from peripheral proprioceptors area must (2). Proprioception contributes to thedevelopment of the motor control and plays amajor role in the reex protection of joints againstpotentially harmful forces (1). The proprioceptiveacuity impairment signicantly affects

neuromusculoskeletal integrity, contributingto pain and functional disability (24). Kneeproprioception has consistently been reportedto be compromised in individuals with kneeosteoarthritis (3,511). This neuromuscular decithas been suggested as the major contributingfactor to the disease process (7,1013). However,studies have shown that the impairment ofproprioceptive acuity is not exclusively a localresult of the disease, and there is a need to study itsimportance in the development and progressionof knee osteoarthritis (10,11).

40Malaysian J Med Sci. Apr-Jun 2011; 18(2): 40-46

mailto:%20vijaybatra%40yahoo.com?subject=mailto:%20vijaybatra%40yahoo.com?subject=mailto:%20vijaybatra%40yahoo.com?subject=mailto:%20vijaybatra%40yahoo.com?subject=mailto:%20vijaybatra%40yahoo.com?subject=

7/31/2019 mjms-18-2-040

2/7

Original Article | Proprioceptive assessment in Knee Osteoarthritis

www.mjms.usm.my 41

There are several ways of measuringproprioceptive acuity; one of them is the thresholddetection of passive movement. However, passivemovements do not reect real life movement orfunction; proprioceptive functions in healthyand pathological joints are quite variable andthere is a lack of correlation between differentmeasurements of proprioception in the knee(1417). Active assessments by asking the patientto replicate limb position, using active movement,with vision occluded (16) or by reproducinglower limb static loads (15) have been suggested.Generally, proprioceptive assessment of the kneeis done in sitting position (16). However, the idealtesting position for proprioceptive assessmentof the knee is still debatable. One of the reasonscould be that, during assessment, the subject

may exhibit an adaptive behaviour to compensatefor the loss of proprioceptive acuity by usingvision or not relaxing the muscles completelybefore attempting to replicate limb position. Thepurpose of the present study was to evaluate theinuence of 2 testing positions (sitting and pronelying) on proprioceptive acuity scores (17) in theassessment of early knee osteoarthritis.

Subjects and Methods

The study involved 70 subjects (22 males

and 48 females) with history of knee pain andclinical diagnosis of early knee osteoarthritis,with radiological ndings of grade I (33 subjects)and grade II (37 subjects) according to theKellgren and Lawrence Classication System(18). All patients were between 40 and 60 yearsof age. Subjects with traumatic knee injury,inammatory arthritis, metabolic disorder, aswell as cardiovascular and psychiatric illnesseswere excluded from the study.

The ethical approval was obtained from TheHuman Ethical Committee of Chhatrapati ShahujiMaharaj Medical University (formerly KingGeorge Medical College), Lucknow. Informedconsent was obtained from the patient or theaccompanying family member.

The baseline evaluation of all the subjectswas done in 2 testing positions (sitting and pronelying) for proprioceptive acuity score (17) usingproprioceptive knee assessment device. Thedevice comprises a goniometer attached witha static bar and a movable set of 5 bars that arexed, with respect to each other, at 10 interval.The central bar of the movable set of 5 bars islonger than the other 4 bars (2 on each side).

The central mechanical axis of the goniometercoincides with the anatomical axis of knee joint.

The static bar corresponds to the 90 of kneeexion, perpendicular to the ground. The centralbar was positioned at the desired angles, i.e., 30and 60 of knee exion (Figure 1). Any deviationfrom the central bar was treated as an error.

With vision occluded, each subject was asked

to perform 30 and 60 exion of each knee for 5times, with intermittent rest intervals of at least1015 seconds. Proprioceptive impairment wascalculated by adding the proprioceptive acuityscores of all the 5 attempts for each knee (Table 1).

Our main objective is to compare the2 test positions; thus, to rule out the possibilityof results being inuenced by certain treatments,the subjects were randomly allocated among 2intervention groups (group 1 and group 2) with35 subjects in each arm. The mean age was notsignicantly different between the 2 groups; themean age for group 1 was 50.14 years (SD 5.49),

while for group 2, it was 51.15 years (SD 5.9). Ingroup 1, context-specic proprioceptive retrainingalong with multijoint coupling strategies (17) wasused, while for group 2, conventional treatmentwas used. Test position 1 (sitting) was consideredas control while test position 2 (prone lying) wasconsidered as experimental.

The context-specic proprioceptive retrainingtechnique incorporated both neurophysiologicaland biomechanical procedures and techniques toinuence neuromusculoskeletal integrity (12,1821) within functional context using facilitatory and

inhibitory procedures, sensorimotor experiences,procedures to enhance dynamic adjustment

Figure 1: Proprioceptive assessment device.

7/31/2019 mjms-18-2-040

3/7

42 www.mjms.usm.my

Malaysian J Med Sci. Apr-Jun 2011; 18(2): 40-46

range, coupled motions of knee, hip, and anklejoints, and multijoint coupling strategies (17).The conventional treatment incorporated jointreproducibility with and without vision occluded,quadriceps strengthening using isometric andisotonic exercises, physical agent modalities,manual therapy, mobilization, and manipulation.

The subjects in each group receivedintervention 3 times per week for 30 minutes persession. At the end of 8 weeks of intervention, eachsubjects proprioceptive acuity was reassessed

in both knees at each angle in both testingpositions (17).

Test position 1 (sitting)Each subject was asked to sit over the plinth

with hip at 90 of exion and knee relaxed andsuspended off the plinth in gravity-dependentposition. Both knees were assessed separately.Initially, the subject was asked to relax for 5minutes. Then, the knee was passively positionedby a therapist using proprioceptive assessmentdevice in 30 of exion, and the subject wasinstructed to replicate the same knee position.The subject was asked to perform 5 trials withintermittent rest intervals of 10 to 15 secondseach. The other knee was also assessed by usingthe same procedure. The similar sequence wasfollowed, for each knee separately, at 60 ofexion.

Test position 2 (prone lying)The subject was asked to lie in prone position

while keeping both the hip and knees neutral (i.e.,hip in 0 of exion or extension, 0 of abduction oradduction, and 0 of internal or external rotation;

knee in full extension). The testing procedure wassame as the procedure for position 1 (sitting).

Statistical analysisIn order to adjust for the discrepancies in

baseline characteristics, the differences of pre-and post-proprioceptive acuity scores were usedfor analysis. Some of these differences werenegative and skewed. Therefore, a logarithmictransformation of the form ln (x + c) was used,where c is a suitably chosen positive constant.Students ttest was performed on the transformeddata. For asymmetrically distributed variables,non-parametric MannWhitney U test was

used.Pvalue of less than 0.05 was considered asstatistically signicant.

Results

All 70 subjects, irrespective of the treatment,were analyzed for their various acuity scores inthe 2 testing positions.

Between-group analysisStudents t test was used for the analysis

of proprioceptive acuity scores of the left kneeat 30 and 60, and the right knee at 60;MannWhitney U test was used for the right kneeat 30. The mean for sitting position for the left kneeat 30 and 60, and the right knee at 60 were 1.498(SD 0.062), 1.515 (SD 0.075), and 1.509 (SD0.072), respectively. The mean for prone lyingposition for the left knee at 30 and 60, and theright knee at 60 were 1.534 (SD 0.059), 1.549 (SD0.069), and 1.55 (SD 0.066), respectively. Themedian and interquartile range in sitting positionfor the right knee at 30 was 1.491 and 0.063,and for prone lying position, 1.505 and 0.071,respectively. The P values at 95 % condence

interval for the change in proprioceptive acuityscores of the left knee at 30 (P < 0.001), the

Table 1: Proprioceptive knee assessment scoring system

Score Description

1 Normal

2 Patient overshoots or undershoots the target by more than 10 but canacquire the target position

3 Patient overshoots or undershoots the target by more than 30 but can

acquire the target position

4 Patient overshoots or undershoots the target by more than 10 and

cannot acquire the target position

5 Patient overshoots or undershoots the target by more than 30 and

cannot acquire the target position

6 Impaired

7/31/2019 mjms-18-2-040

4/7

Original Article | Proprioceptive assessment in Knee Osteoarthritis

www.mjms.usm.my 43

left knee at 60 (P = 0.007), and the right kneeat 60 (P< 0.001) were found to be statisticallysignicant (Table 2).

Between-group analysisThe subgroup analyses were also done to ruleout the treatment effect. Students ttest was usedfor the analysis of proprioceptive acuity scores ofthe left knee at 30 and 60, and the right knee at60; MannWhitney U test was used for the rightknee at 30.

The mean proprioceptive acuity score forsitting position (group 1) for the left knee at 30and 60, and the right knee at 60 were 1.532 (SD0.049), 1.564 (SD 0.043), and 1.554 (SD 0.041),respectively. In prone lying position, the valueswere 1.568 (SD 0.051), 1.598 (SD 0.043), and

1.598 (SD 0.040), respectively. The median andinterquartile range in sitting position for the rightknee at 30 was 1.519 and 0.039; for prone lyingposition, they were 1.531 and 0.051, respectively(Table 3). The changes in proprioceptive acuityscores of the left knee at 30 (P= 0.004), the leftknee at 60 (P= 0.002), and the right knee at 60(P< 0.001) were statistically signicant, whereasno signicant difference was observed for theright knee at 30 (P= 0.068) (Table 3).

The mean proprioceptive acuity score forsitting position (group 2) for the left knee at 30

and 60, and right knee at 60 were 1.464 (SD0.055), 1.467 (SD 0.069), and 1.464 (SD 0.068);for prone lying position, the mean values were1.501 (SD 0.047), 1.500 (SD 0.052), and 1.502 (SD0.051), respectively. The median and interquartilerange in sitting position for the right knee at 30was 1.462 and 0.076; for prone lying position, theywere 1.477 and 0.044, respectively.The changes inproprioceptive acuity scores of the left knee at 30(P= 0.004), the left knee at 60 (P= 0.028), andthe right knee at 60 (P= 0.009) were statisticallysignicant, whereas no signicant difference wasobserved for the right knee at 30 (P = 0.162)(Table 4).

Discussion

Based on the analyses, null hypothesisstating that both sitting and prone lying positionsare equally effective for assessing proprioceptiveacuity impairment in knee osteoarthritis can berejected; the prone lying test position was found tobe more sensitive than the sitting position in mostof the components. The results can be explainedbased on the neurophysiological mechanism of

neuromuscular control system.

In early knee osteoarthritis, the kneejoint complex is richly innervated withmechanoreceptors, such as receptors in the joint,skin, and muscle (22,23). The combination of

both muscle and joint receptors forms an integralcomponent of a complex sensorimotor system thatplays a major role in the proprioceptive mechanism(24,25). Mechanoreceptors can be quick-adaptingand slow-adapting, and they have differentshapes, threshold levels, locations, and adaptiveproperties based on their response to stimuli(23,2527). Quick-adapting mechanoreceptorsmediate the sensation of joint motion, whereasthe slow-adapting mechanoreceptors mediate thesensation and change in joint position (22,23). Theproprioceptive mechanism, which is initiated byactivation of these mechanoreceptors, has direct

implication over proprioceptive acuity score ofthe knee. Since proprioceptive acuity score of eachknee has a combined effect over the functionalstatus, in the present study, proprioceptiveimpairment of each knee was assessed separatelyto identify the ideal test position.

Statistical analysis showed mixed results,but the prone lying position was found to be moresensitive for assessing proprioceptive acuity statusthan the sitting position. In prone lying, the kneearc of motion starts from extension to exion, withboth knees and hip in neutral; the direct inuence

of gravity and the effect of diarthodial muscles arenullied, and the length feedback is controlled ina better manner. As a result, mechanoreceptors(especially slow-adapting) do not get stimulated,and the knees can be fully relaxed. On the otherhand, in sitting position, the hip and the knees arein 90 of exion, and the knee arc of motion startsfrom 90 knee exion to extension. In addition,the muscles around knee, being diarthodial, areunder the direct inuence of gravity, and themuscle stretch reex activity may get stimulated.The proprioceptive acuity scores obtained insitting position may not represent the actualproprioceptive acuity status of each knee.

Motor control relies on inputs fromproprioceptors, visual receptors (telereceptors),and vestibular receptors. When kneeproprioceptive acuity gets impaired, the subjectmay exhibit adaptive behaviours (23,25,26) toaccommodate proprioceptive decit by relying onvision or not allowing the muscles to get relaxedbefore attempting to replicate limb position. Inthe present, study this adaptive behaviour wasdrastically minimized by occluding the visionand incorporating intermittent rest intervals.

However, in prone lying position, the reliance

7/31/2019 mjms-18-2-040

5/7

44 www.mjms.usm.my

Malaysian J Med Sci. Apr-Jun 2011; 18(2): 40-46

on vision and muscle tension as well as the effectof diarthodial muscles on the proprioceptiveacuity could be ruled out. Both test positionswere equally sensitive in the assessment ofproprioceptive acuity for the right knee at 30.Therefore, each test position is useful in differentmethods of assessment. Since onset of kneeosteoarthritis is usually unilateral and may laterprogress bilaterally, the proprioceptive acuityscores of each knee can guide the treatment

process. Hence, the null hypothesis was rejected.

Conclusion

The prone lying position is more sensitive thanthe sitting position in assessing proprioceptiveacuity of each knee and identifying the actualproprioceptive impairment status. Prone lyingposition could serve as an effective evaluation toolto guide the treatment process in patients withearly knee osteoarthritis.

Table 2: Comparison of the changes in proprioceptive acuity scores (pre- and post-interventionbetween sitting and prone lying positions

ProprioceptiveAcuity

Left Knee Right Knee

30a

60a

30b

60a

Sitting position 1.498 (0.062) 1.515 (0.043) 1.491 (0.063) 1.509 (0.072)

Prone lying position 1.534 (0.059) 1.549 (0.685) 1.505 (0.071) 1.550 (0.066)

Test statistics (df) -3.525 (138) -2.741 (138) -1.576 -3.532 (138)

Pvalue

7/31/2019 mjms-18-2-040

6/7

Original Article | Proprioceptive assessment in Knee Osteoarthritis

www.mjms.usm.my 45

Acknowledgements

We are thankful to the Indian Council forMedical Research for their nancial support.

Authors Contributions

Conception and design, collection and assemblyof the data: VB, MBDrafting and nal approval of the article: VB,VPS, MB, VSStatistical expertise: GGA

Correspondence

Dr Vijay Batra

PhD Occupational Therapy (Chhatrapati Shahuji

Maharaj Medical University)Department of Physical Medicine & Rehabilitation

Rehabilitation and Articial Limb CentreChhatrapati Shahuji Maharaj Medical University(Formerly King George Medical University)

Dali Ganj Bridge, Nabiullah RoadLucknow: 226018Uttar Pradesh, India

Tel: +91-9868019077, +91-9044467434Email: vijaybatra@yahoo.com,

vijaybatras@gmail.com

References

1. Gandevia SC. Kinesthesia: Roles for afferent signalsand motor commands. In: Rowell LB, ShepardJT, editors. Handbook on integration of motor,circulatory, respiratory and metabolic control duringexercise. Bethesda, MD: American PhysiologicalSociety; 1996. p. 128172.

2. Riemann BL, Lephart SM. The sensorimotor system,part I: The physiologic basis of functional jointstability.J Athl Train. 2002;37(1):7179.

3. Felson DT, Gross KD, Nevitt MC, Yang M, Lane NE,Torner JC, et al. The effects of impaired joint positionsense on the development and progression of pain andstructural damage in knee osteoarthritis. Arthritis

Rheum. 2009;61(8):10701076.

4. Bennell KL, Hinman RS, Metcalf BR, CrossleyKM, Buchbinder R, Smith M, et al. Relationship ofknee joint proprioception to pain and disability inindividuals with knee osteoarthritis. J Orthop Res.2003:21(5):792797.

5. Barrett DS, Cobb AG, Bently G. Joint proprioceptionin normal, osteoarthritic and replaced knees. J Bone

Joint Surg. 1991;73(1):5356.

6. Garsden LR, Bullock-Saxton JE. Joint repositionsense in subjects with unilateral osteoarthritis of theknee. Clin Rehabil. 1999;13(2):148155.

7. Hurley MV, Scott DL, Rees J, Newham DJ.Sensorimotor changes and functional performancein patients with knee osteoarthritis.Ann Rheum Dis.1997:56(11):641648.

8. Marks R. Further evidence of impaired position

sense in knee osteoarthritis. Physiother Res Int.1996;1(2):127136.

9. Pai YC, Rymer WZ, Chang RW, Sharma L. Effectof age and osteoarthritis on knee proprioception.

Arthritis Rheum. 1997;40(12):22602265.

10. Sharma L, Pai YC. Impaired proprioception andosteoarthritis. Curr Opin Rheumatol. 1997;9(3):253258.

11. Sharma L, Pai YC, Holtkamp K, Rymer WZ. Is kneejoint proprioception worse in the arthritic knee versusthe unaffected knee in unilateral knee osteoarthritis?

Arthritis Rheum. 1997;40(8):15181525.

12. Hurley MV, Scott DL. Improvement in quadricepssensorimotor function and disability of patients withknee osteoarthritis following a clinically practicableexercise regime. Br J Rheumatol. 1998:37(11):11811187.

13. Salo P. The role of joint innervation in the pathogenesisof arthritis. Can J Surg. 1999;42(2):91100.

14. Grob KR, Kuster MS, Higgins SA, Lloyed DG, Yata H.Lack of correlation between different measurementsof proprioception in the knee. J Bone Joint Surg Br.2002:84(4):614618.

15. Murtaugh K, Costigan PA, Evaluating theproprioception of lower extremity loads. Winter.

2003:6(2):1519.

16. Olson L, Lund H, Henriksen M, Rogind H, BliddalH, Danneskiold-Samsoe B. Testretest reliabilityof a knee joint position sense measurement methodin sitting and prone position. Adv Physiother.2004;6(1):3747.

17. Batra V, Sharma VP, Batra M, Agarwal GG, Sharma V.Multi-joint coupling strategies to enhance functionalrecovery in knee osteoarthritis.Ind J Phys Occ Ther.Forthcoming.

18. Hochberg MC, Altman RD, Brandt KD, Clark BM,Dieppe PA, Grifn MR, et al. Guidelines for the medicalmanagement of osteoarthritis. Part I. Osteoarthritis of

the hip. American College of Rheumatology.ArthritisRheum. 1995;38(11):15351540.

19. Hurley MV. Muscle dysfunction and effectiverehabilitation of knee osteoarthritis: What we knowand what we need to nd out. Arthritis Rheum.2003;49(3):444452.

20. Farina D, Arendt-Nielsen L, Graven-Nielsen T.Experimental muscle pain reduces initial motorunit discharge rates during sustained sub maximalcontractions.J Appl Physiol. 2005;98(3):9991005.

21. Smania N, Picelli A, Romano M, Negrini S.Neurophysiological basis of rehabilitation ofadolescent idiopathic scoliosis. Disabil Rehabil.

2008;30(10):763771.

7/31/2019 mjms-18-2-040

7/7

46 www.mjms.usm.my

Malaysian J Med Sci. Apr-Jun 2011; 18(2): 40-46

22. Sekir U, Gur H. A multi-station proprioceptiveexercise program in patients with bilateral kneeosteoarthrosis: Functional capacity, pain andsensorimotor function. A randomized controlled trial.

J Sports Sci Med. 2005:4:590603.

23. Williams GN, Chmielewski T, Rudolph K, BuchananTS, Snyder-Mackler L. Dynamic knee stability: Currenttheory and implications for clinicians and scientists.JOrthop Sports Phys Ther. 2001;31(10):546566.

24. Dixon J, Howe TE. Quadriceps force generationin patients with osteoarthritis of the knee andasymptomatic participants during patellar tendonreex reactions: An exploratory cross-sectional study.

BMC Musculoskelet Disord. 2005:6:46.

25. Houk JC. Regulation of stiffness by skeletomotorreexes.Annu Rev Physiol. 1979:41:99114.

26. Houk JC, Rymer WZ. Neural control of muscle lengthand tension. In: Brooks VB, editor. Handbook of

physiology: Section I. The nervous system. Volume 2:

Motor control. Bethesda, MD: American PhysiologicalSociety; 1981. p. 257323.

27. Nichols TR, Cope TC, Abelew TA. Rapid spinalmechanisms of motor coordination. Exerc Sport Sci

Rev. 1999:27:255284.