©Journal of Sports Science and Medicine (2005) 4, 590-603 http://www.jssm.org Research article A MULTI-STATION PROPRIOCEPTIVE EXERCISE PROGRAM IN PATIENTS WITH BILATERAL KNEE OSTEOARTHROSIS: FUNCTIONAL CAPACITY, PAIN AND SENSORIOMOTOR FUNCTION. A RANDOMIZED CONTROLLED TRIAL Ufuk Sekir and Hakan Gür Sports Medicine Department, Faculty of Medicine, Uludag University, Bursa, Turkey Received: 5 August 2005 / Accepted: 19 November 2005 / Published (online): 01 December 2005 ABSTRACT We investigated the effects of a multi-station proprioceptive exercise program on functional capacity, perceived knee pain, and sensoriomotor function. Twenty-two patients (aged 41-75 years) with grade 2-3 bilateral knee osteoarthrosis were randomly assigned to two groups: treatment (TR; n = 12) and non- treatment (NONTR; n = 10). TR performed 11 different balance/coordination and proprioception exercises, twice a week for 6 weeks. Functional capacity and perceived knee pain during rest and physical activity was measured. Also knee position sense, kinaesthesia, postural control, isometric and isokinetic knee strength (at 60, 120 and 180°·s-1) measures were taken at baseline and after 6 weeks of training. There was no significant difference in any of the tested variables between TR and NONTR before the intervention period. In TR perceived knee pain during daily activities and functional tests was lessened following the exercise program (p < 0.05). Perceived knee pain was also lower in TR vs. NONTR after training (p < 0.05). The time for rising from a chair, stair climbing and descending improved in TR (p < 0.05) and these values were faster compared with NONTR after training (p < 0.05). Joint position sense (degrees) for active and passive tests and for weight bearing tests improved in TR (p < 0.05) and the values were lower compared with NONTR after training (p < 0.05). Postural control (‘eyes closed’) also improved for single leg and tandem tests in TR (p<0.01) and these values were higher compared with NONTR after training. The isometric quadriceps strength of TR improved (p < 0.05) but the values were not significantly different compared with NONTR after training. There was no change in isokinetic strength for TR and NONTR after the training period. The results suggest that using a multi-station proprioceptive exercise program it is possible to improve postural control, functional capacity and decrease perceived knee pain in patients with bilateral knee osteoarthrosis. KEY WORDS: Osteoarthrosis, proprioception, balance, perceived knee pain, function. INTRODUCTION and Silman, 1987). This condition usually occurs late in life, principally affecting the hand, and large Osteoartrhosis (OA) is a slowly evolving articular weight bearing joints such as the knee (Mankin, disease, which appears to originate in the cartilage 1989). It is particularly disabling when the knees are and affects the underlying bone, soft tissues and affected since the ability to walk, to rise from a chair synovial fluid (Badley and Tennant, 1992; Kirwan and to use stairs is limited. Since, 30-40% of the Proprioceptive exercises in knee osteoarthrosis 591 elderly population over the age of 60 years suffers criteria of the American College Rheumatology from knee OA (Felson, 1990) the condition is likely (Altman et al., 1986), based on weight-bearing to contribute to disability in this population. radiographs were admitted to the study. None of the Impaired proprioception has been reported for patients had any neurological disorder (e.g. the patients suffering from knee osteoarthrosis Parkinson’s, Alzheimer’s) and/or a vestibular (Barret et al., 1991; Hassan et al., 2001; Hurley et disorder, previous surgery on either knee, or al., 1997). However, few investigations (Hurley et symptomatic disease of the hip, ankle, or foot. In al., 1997; Marks, 1994a; Swanik et al., 2000) have addition, none of the volunteers had received intra- investigated the relationship between impaired articular steroid or hyaluronic acid injections in the proprioception and performance or other measures preceding 6 months, neither had they received of functional status in OA. The integrity and control physiotherapy treatment, nor had they any knee of sensorimotor systems that is, proprioceptive cruciate ligament injury. The patients were informed acuity and muscle contraction are essential for the about testing procedures, possible risks and maintenance of balance and production of a smooth, discomfort that might ensue and gave their written stable gait (Fitzpatrick and McCloskey, 1994; Lord informed consent to participate in accordance with et al., 1996). If knee OA impairs quadriceps function the Helsinki Declaration (WMAD, 2000). this may also impair the patient’s balance and gait, All subjects were employed in an office or reducing their mobility and function. In addition, were retired, spending most of the day sitting. The quadriceps sensory dysfunction, i.e. decreased activity level for all subjects remained relatively proprioceptive acuity, has recently been constant during the experimental period. The demonstrated in patients with knee OA and proposed patients were randomly assigned to two groups: as a factor in the pathogenesis or progression of the treatment (TR; n = 12, [9 women and 3 men], age condition (Birmingham et al., 2001; Hurley et al., 59 ± 8.9 years; height 1.58 ± 0.09 m and body mass 1997; Koralewicz and Engh, 2000). If correct, 81.6 ± 13.8 kg) and non-treatment (NONTR; n = 10, restoration of these sensorimotor deficits with [7 women and 3 men], age 62 ± 8.1 years; height rehabilitation may retard progression of knee OA 1.58 ± 0.09 m and body mass 74.6 ± 8.8 kg). and reduce disability. Gait training, biofeedback, electric stimulation, and facilitation techniques Perceived knee pain primarily used in the rehabilitation of patients with Pain was subjectively evaluated using a 0 –100 mm neurologic impairments have been proposed as visual analog scale (VAS, 0 = no pain; 100 = alterative approaches to enhance proprioception unbearable pain), which assesses the severity of pain (Marks, 1994b). Although it is generally accepted in general, at night, after inactivity, sitting, rising that a rehabilitation program improves the functional from a chair, standing, walking and stair climbing. capacity, pain and sensoriomotor function of patients They were also asked to rate the pain perceived in (Rogind et al., 1998; Hurley, 2003; Hurley and their knee immediately after the functional capacity Scott, 1998; Hurley et al., 1997, Kettunen and tests. Kujala, 2004; Roddy et al., 2005), there is lack of agreement about what such a rehabilitation program Functional capacity measurements should include (Bijlsma and Dekker, 2005; Hurley, Patients indicated a subjective scoring of an 2003; Kettunen and Kujala, 2004; Roddy et al., appropriate number on a 0 to 10 point Numerical 2005). In addition, many previous studies have Rating Scale (0 = minimal functional capacity; 10 = generally used sophisticated and expensive maximal functional capacity) for chair rise, standing, apparatus, which limits their application to a walking, stair climbing and descending. In addition, community setting. functional capacity was also measured by a chair rise The purpose of the present study was to and15-m walk and stair climbing and descending investigate the effects of a 6 week multi-station tests (Gür et al., 2002). proprioceptive exercise program on functional Standing-up From a Chair and 15-m Walking capacity, perceived knee pain, and sensoriomotor Test: Patients were seated on a chair before a start function in patients with bilateral knee line. A hand-held stopwatch was started on the osteoartrhosis. command “Go!”, and the patients rose from the chair, without arm support, and walked as fast as METHODS possible along a level, unobstructed corridor. The stopwatch was stopped immediately they passed a second mark 15-m from the start. Patients Two trials, interspersed with a 5 min rest Twenty-two patients with bilateral complaints of interval, were performed for all functional tests - and knee OA, who had grade 2 or 3 OA, as judged by the better test result recorded. The reliability 592 Sekir and Gür coefficients (r) for repeated measures of the difference between the target and replicated angle functional tests for OA patients varied from 0.97 to (in degrees), averaged over the 2 target angle 0.99 (Gür et al., 2002). replication attempts. Kinaesthesia: With the subject’s knee at a Sensoriomotor tests 45° angle of flexion, the researcher attached the During sensoriomoter tests, subjects were lever arm of the Cybex. The Cybex dynamometer blindfolded and they wore shorts to negate any extended or flexed the knee at 1° s -1 until the subject extraneous skin sensation from clothing touching the detected passive motion or a change in joint knee area. position. The subject was then asked to identify the Joint Position Sense Tests (active and direction (flexion or extension) of the knee passive): The perceived sense of knee joint position movement. The direction of the trial was was quantified as the ability to replicate target joint randomized, and the researcher recorded both the angles using a computerized dynamometer (Cybex stop position (threshold to detection of passive 6000, USA). Subjects were blindfolded and seated motion) and the direction (measured in degrees of on the dynamometer at a 105° trunk angle - with the angular displacement for each trial). Six randomized back supported and the knee hanging over the edge tests (three for flexion and three for extension) were of the chair. The lever arm was of the dynamometer conducted on the dominant leg. The outcome passively moved from 90° (0° = knee fully measure used for the threshold to detection was extended) to 1 of 3 randomly allocated target angles averaged over the 3 trials, for each direction, in of 20, 45 and 70° of knee flexion by the degrees. experimenter using a speed of 1°·s-1 - which was Balance Tests: After one practice trial, maintained for 10 seconds. Subjects then returned subjects completed 3 consecutive test trials for both the knee to the start position (90° of flexion) and, ‘eyes open’ and ‘eyes closed’ in the following order: after a 5-second rest, attempted to reproduce the 1) Romberg bilateral, 2) unilateral (single leg previously attained target angle passively and standing) stance test on both extremities and 3) actively (speed of 1°·s-1) stopping when they Tandem stance. All static balance tests were perceived that the angle had been replicated. All performed on a medium-density polyfoam mat. subjects completed 3 different target angle During ‘eyes open’ balance tests, subjects looked replication attempts, with a 30-second rest between straight ahead at a cross marked at approximately each trial. Angular position was continuously eye level on the wall 2-m away. For bilateral recorded by the dynamometer throughout each trial Romberg test, subjects stood on both feet, without to permit subsequent calculation of the difference arm support. For unilateral Romberg test, subjects between target and replicated angle. No feedback stood on the test side limb with their stance foot regarding performance was provided. After one centred on the mat and with their knee in slight practice trial, subjects completed 3 consecutive test flexion. They were instructed to lift the limb that trials. The outcome measure used for the was not being tested by bending the knee, and proprioception test was an error score calculated as holding it at approximately 90° of knee flexion. the average absolute difference between the target Once the subjects were in this position, and stated and replicated angle (in degrees), averaged over the that they were ready, data collection was initiated. 3 target angle replication attempts. For each test balance measurements were performed Weight Bearing Joint Position Test: The for a maximum 30 seconds (provided subjects did protocol for testing knee joint position sense in the not move their body or make contact with the full weight bearing position was a modification of ground). Subjects were asked to stand unsupported that reported by Bullock–Saxton et al. (2001) The with their arms at their side. The subjects performed test was performed at 15 and 30° of knee flexion. these tests without shoes and socks to negate any Rotation axis of a standard goniometer was placed extraneous skin sensation from clothing touching the on the lateral side of the dominant knee joint when foot area. The outcome measure (time in seconds) subjects remained standing. The dominant knee was used for the balance assessment was averaged over fully extended (0°) at the starting position and the 2 trials, for each test situation. moved randomly to the allocated target angles of 15 or 30° of knee flexion - which was maintained for 5 Strength tests seconds. Subjects then returned the knee to the start The tests were completed on a Cybex 6000 position and, after a 5-second rest, attempted to computer-controlled isokinetic dynamometer, as reproduce the previously attained target angles. The previously described (Gür et al., 2002). Subjects outcome measure used for the reposition tests was performed a 5 second isometric contraction for each an error score calculated as the average absolute Proprioceptive exercises in knee osteoarthrosis 593 Table 1. Perceived knee pain (VAS score) of patients during daily activities. Data are means (interquartile range). Baseline After 6 weeks At night Training 4.4 (2.4, 6.7) 1.9 (.2, 2.6) **†† Non-training 4.8 (2.8, 6.7) 4.1 (1.7, 6.4) After Training 5.0 (3.6, 7.0) 1.9 (.4, 2.4) **† inactivity Non-training 5.3 (3.5, 7.6) 4.0 (1.5, 7.0) Sitting Training 4.7 (2.6, 7.4) 1.8 (.0, 3.1) **† Non-training 5.0 (2.5, 6.9) 4.0 (2.8, 5.1) Chair Rise Training 6.0 (3.8, 8.9) 2.4 (.3, 4.2) **† Non-training 5.5 (3.6, 7.8) 4.9 (2.9, 6.6) Standing Training 5.1 (1.3, 8.8) 2.7 (.4, 4.5) ** Non-training 6.6 (4.6, 8.5) 4.6 (1.8, 7.5) ** Descending Training 6.4 (4.0, 8.9) 2.9 (.6, 4.6) **†† stairs Non-training 7.5 (6.3, 8.5) 6.9 (6.2, 8.6) Stair Training 6.1 (5.0, 7.4) 2.9 (.7, 5.5) **†† climbing Non-training 6.2 (3.1, 8.7) 5.6 (4.0, 7.7) Total Training 37.6 (27.1, 51.2) 16.6 (6.0, 25.0) **†† Non-training 40.8 (36.1, 47.0) 34.2 (28.4, 42.9) ** p < 0.01 compared with baseline value. † p < 0.05 and †† p < 0.01 compared with NONTR. of 4 maximal repetitions at the angular velocity of Data was analyzed using non-parametric tests. 0°·s-1 in both legs following three consecutive Probability values of less than or equal to 0.05 were submaximal warm-up trials for each muscle group. considered to be significant, and all tests were two- A 3 min rest was allowed between each leg. For the tailed. To compare groups a Mann-Whitney U-test isometric test, 60 and 30° of knee angle were used was used. A Wilcoxon signed rank test was for quadriceps and hamstring muscles, respectively. performed to compare changes from baseline to six Conventional concentric continuous weeks. Statistical analyses were performed using (reciprocal) isokinetic tests were used (Gür et al., SPSS 10.0.1 for Windows. Data in the Tables are 2002). During the tests, the subjects performed 4 presented means (interquartile ranges). maximal reciprocal flexion-extension repetitions for each angular velocity of 60, 120 and 180°·s-1 for RESULTS both legs. The concentric tests were performed after the isometric tests. A 20 min rest was allowed between the concentric and isometric tests, and Patients between measures on each leg. There were no significant differences in the tested variables between TR vs. NONTR before training Multi-station exercise program (Tables 1-6). No one (TR) wished to withdraw from TR performed a multi-station exercise program (for training – and all subjects completed the whole detail see Appendix). Prior to the multi-station training schedule. During the functional exercises exercise program, in order to warm-up, subjects mean (±SD) heart rates of subjects for weeks 1, 3, walked on a treadmill (Woodway, USA) at a speed and 5 were 100 (±10), 97 (±8) and 96 (±14) b·min -1, of 4 km·h-1 for 10 min. respectively. All tests were performed before and after 6 weeks training by the same assessors for both TR Knee pain and NONTR. Heart rate was recorded during the Following the exercise program, in TR, perceived whole body exercises to determine exercise intensity knee pain for daily activities decreased significantly (Polar Vantage NV telemeters; Polar Electro Oy, (p < 0.01 to p < 0.05; Table 1). The perceived knee Finland) during weeks 1, 3 and 5. An average heart pain for daily activities (except for standing) was rate was calculated for each individual. significantly (p < 0.01 to p < 0.05) lower in TR compared with NONTR following training (Table Statistics 1). 594 Sekir and Gür Table 2. Perceived knee pain (VAS score) of patients during functional tests. Data are means (interquartile range). Baseline After 6 weeks 15-m walk Training 3.5 (1.0, 6,9) 1.6 (.0, 2.7) **†† Non-training 3.4 (1.7, 5.6) 3.9 (1.3, 6.3) Stand-up and Training 3.6 (.9, 6.7) 2.0 (.1, 4.1) *†† 15-m walk Non-training 3.3 (1.5, 5.4) 4.7 (2.2, 6.8) * Chair Rise Training 4.1 (.8, 8.1) 2.1 (.1, 4.7) **† Non-training 5.9 (3.6, 8.6) 5.6 (3.4, 8.8) Descending Training 4.5 (1.5, 7.1) 2.0 (.2, 3.6) **†† stairs Non-training 5.3 (3.0, 6.6) 5.0 (2.0, 7.3) Stair Training 3.5 (1.1, 5.8) 1.8 (.1, 2.9) **†† climbing Non-training 4.7 (2.9, 7.0) 4.0 (2.5, 5.1) Total Training 19.3 (7.2, 33.8) 9.5 (.8, 19.8) **†† Non-training 22.6 (18.4, 32.3) 23.2 (13.0, 34.0) * p < 0.05 and ** p < 0.01 compared with baseline value. † p < 0.05 and †† p < 0.01 compared with NONTR. The perceived knee pain during functional The subjective ratings for daily activities were tests was also significantly (p < 0.01 to p < 0.05) significantly improved following the exercise improved in TR compared with baseline (Table 2). program in TR (Table 3). TR had significantly better In NONTR the perceived knee pain during chair rise activity level compared with NONTR after training and 15-m walk was significantly worse compared (Table 3). The time in seconds for functional tests with baseline values. The perceived knee pain were also significantly improved in TR compared during all functional tests was significantly lower in with baseline (Table 4). The most marked changes TR compared with NONTR following training were observed in descending and ascending stairs. (Table 2). TR had significantly faster performance times for chair rise, descending and ascending stairs compared Functional performance with NONTR following the 6 week training period (Table 4). Table 3. Subjective rating of daily activities. Data are means (interquartile range). Baseline Post-exercise 15-m walk Training 3.0 (2.0, 5.8) 8.3 (7.1, 9.5)**† Non-training 2.8 (1.9, 5.1) 4.8 (3.2, 7.6)* Chair Rise Training 3.3 (1.2, 6.7) 8.4 (7.3, 9.9)**† Non-training 2.9 (2.0, 8.6) 3.9 (3.0, 7.3) Standing Training 5.8 (2.8, 8.3) 8.1 (7.4, 9.6)**†† Non-training 4.1 (2.0, 6.1) 4.8 (2.6, 7.1) Descending Training 3.5 (2.0, 6.2) 7.3 (5.6, 9.2)**†† stairs Non-training 1.9 (1.5, 3.9) 2.6(1.5, 4.4) Stair Training 4.2 (2.8, 6.2) 7.3 (5.4, 9.1)**† climbing Non-training 2.9 (1.1, 4.2) 4.3 (2.7, 6.0) Total Training 22.4 (15.0, 30.1) 40.0 (34.2, 44.5)**†† Non-training 17.6 (10.8, 23.0) 21.1 (15.7, 28.2) * p < 0.05 and ** p < 0.01 compared with baseline value. † p < 0.05 and †† p < 0.01 compared with NONTR. Proprioceptive exercises in knee osteoarthrosis 595 Table 4. Time (s) during the functional tests. Data are means (interquartile range). Baseline After 6 weeks 15-m walk Training 10.3 (9.1, 11.8) 9.4 (8.3, 10.8) ** Non-training 12.1 (10.6, 13.3) 11.9 (10.5, 13.1) Stand-up and Training 11.3 (10.7, 12.9) 10.0 (8.6, 11.5) ** 15-m walk Non-training 13.3 (11.7, 15.5) 12.6 (10.8, 14.6) * Chair Rise Training 30.2 (26.8, 34.8) 26.5 (23.2, 31.9) **† Non-training 32.8 (28.8, 35.4) 31.8 (28.9, 33.1) Descending Training 8.1 (6.6, 9.9) 6.2 (5.2, 6.9) **†† stairs Non-training 10.9 (6.6, 13.3) 10.3 (6.6, 10.2) Stair Training 8.2 (7.0, 9.7) 7.0 (6.0, 8.3) **† climbing Non-training 9.2 (7.2, 9.5) 8.9 (7.0, 9.2) Total Training 68.2 (58.6, 74.1) 59.1 (51.9, 63.6) **†† Non-training 78.3 (67.5, 93.8) 75.5 (63.9, 85.3) * p < 0.05 and ** p < 0.01 compared with baseline value. † p < 0.05 and †† p < 0.01 compared with NONTR. Joint position sense significantly lowered kinaesthesia (degrees) Active and passive knee joint position senses’ error compared with NONTR after 6 weeks (Table 6). scores (JPS) at 20, 45 and 70º were similar in TR and NONTR before the intervention. After 6 weeks, Weight bearing joint position sense JPS at all tested angles showed significant Position error at 15 and 30° of knee flexion improvement for active and passive tests in TR improved significantly compared with baseline compared with baseline. After 6 weeks, except for values in TR. In NONTR there was a no significant the active test at 45° and the passive test at 70°, TR change at 15° whereas JPS worsened at 30° of knee had significantly lower values compared with flexion compared with baseline values (Table 7). NONTR (Table 5). Overall there were no significant differences between TR and NONTR at the end of training. Kinaesthesia The threshold to detection in degrees was Balance tests significantly improved in TR and NONTR for The time for Romberg bilateral test performed ‘eyes flexion and extension after 6 weeks. TR had a open’ and ‘eyes closed’ were not significantly Table 5. Position sense error scores (degrees) of the patients at 20°, 45° and 70°of knee angles. Data are means (interquartile range). Baseline After 6 weeks Active 20° Training 8.8 (5.8, 12.8) 5.5 (3.9, 6.2) **†† Non-training 5.8 (2.8, 8.3) 10.4 (4.5, 15.0) Active 45° Training 7.4 (4.0, 11.3) 3.0 (2.0, 3.7) ** Non-training 6.9 (3.3, 9.5) 5.6 (3.9, 7.1) Active 70° Training 6.7 (3.9, 10.3) 3.7 (2.8, 4.5) **† Non-training 7.2 (2.6, 11.3) 8.0 (4.0, 10.6) Passive 20° Training 10.1 (3.1, 16.4) 4.4 (2.1, 6.7) **†† Non-training 7.0 (2.9, 13.0) 8.6 (4.6, 13.6) Passive 45° Training 6.8 (4.3, 9.4) 3.7 (2.3, 5.9) **† Non-training 6.6 (5.0, 7.4) 6.3 (3.9, 7.7) Passive 70° Training 6.8 (4.8, 9.7) 4.5 (3.3, 6.5) * Non-training 7.7 (3.8, 9.5) 6.1 (3.2, 7.9) * p < 0.05 and ** p < 0.01 compared with baseline value. † p < 0.05 and †† p < 0.01 compared with NONTR. 596 Sekir and Gür Table 6. Kinesthesia (the threshold to detection in degrees) test results of subjects. Data are means (interquartile range). Baseline After 6 weeks Flexion Training 2.3 (1.4, 3.0) 1.3 (1.0, 1.4) *† Non-training 2.9 (1.6, 4.2) 2.5 (1.3, 3.5) Extension Training 2.4 (1.7, 3.6) 1.5 (1.3, 1.7) *† Non-training 2.8 (2.3, 3.5) 2.5 (1.7, 2.9) * p < 0.05 and ** p < 0.01 compared with baseline value. † p < 0.05 and †† p < 0.01 compared with NONTR. changed in either group compared with baseline perceived pain scores, and increases in functional values (Table 8). However, the times for Romberg capacity together with a significant increase in unilateral tests performed ‘eyes open’ and ‘eyes postural control. In addition, despite their severe closed’ improved in TR compared with baseline disability the patients showed a remarkable values (p < 0.01). These values were significantly compliance both with the training program and with higher compared with NONTR after training (Table the evaluation protocol, participating in all of the 8). The time for the Tandem test performed ‘eyes training and assessment sessions. closed’ was significantly improved for TR compared O’Reilly and co-workers (1999) used with baseline values. These values were significantly isometric quadriceps, isotonic quadriceps and greater compared with NONTR after training (Table hamstring exercises, and dynamic stepping exercise 8). However, the Tandem test, performed ‘eyes daily for 6 months in OA patients. They evaluated open’ showed no change compared with baseline pain perceived during walking, ascending- values for TR and NONTR after training.. descending stairs (using the visual analogue scale) and physical function score and found that they were Muscle strength improved by 20.9, 18.6, and 17.4 %, respectively, in After 6 weeks, isometric strength of the quadriceps an exercise group (O’Reilly et al., 1999). In the in TR and hamstring strength in NONTR were present study, the perceived pain score during significantly (p < 0.05) improved compared with walking and stair climbing, and the mean physical baseline values. There were no significant function score improved 61.5, 62.1, and 62.5% differences between the groups for isometric respectively following training. Although quadriceps and hamstring strengths after differences in methods limit the comparison between intervention period. In addition, concentric two studies, there was a greater magnitude of change quadriceps and hamstring strengths of patients in in the present study. both groups showed no significant change following Fisher and colleagues (1991) used isometric, the training period (Table 9). in addition to isotonic, training in a program lasting 16 weeks in a similar group of patients (knee OA). DISCUSSION They reported that improvements in 15-m walk time and functional performance were approximately 9% Reviewing the literature, a pure proprioceptive for both groups after an 8 week intervention. After program including several balance exercises, has not 16 weeks improvements were approximately 12 and been used in patients with severe knee OA. We 25%, respectively (Fisher et al., 1991). In the present expected that the program would lead to an study the improvement in 15-m walk time was improvement in proprioceptive/balance capabilities similar to that reported by Fisher et al. (1991) with a in TR and therefore to improvements in functional value of 8.7±1.0% - but the subjective rating in daily capacity and a decrease in perceived knee pain. In activities was double (61.4±17.6%) compared with summary, TR showed a marked decrease in values reported by Fisher and colleagues (1991). Table 7. Weight bearing Joint Position Sense (position error, degrees) test results of subjects. Data are means (interquartile range). Baseline After 6 weeks 15° Training 3.0 (1.8, 3.8) 1.3 (.8, 1.9) ** Non-training 4.0 (1.6, 5.4) 2.9 (1.3, 4.2) 30° Training 3.4 (2.2, 4.0) 1.5 (1.3, 2.0) ** Non-training 3.7 (1.6, 5.1) 3.1 (1.9, 4.4) ** p < 0.01 compared with baseline value. Proprioceptive exercises in knee osteoarthrosis 597 Table 8. Postural control - time (s) during the balance tests of the patients. Data are means (interquartile range). Baseline After 6 weeks Romberg bil Training 30.0 (30.0, 30.0) 30.0 (30.0, 30.0) eyes open Non-training 30.0 (30.0, 30.0) 30.0 (30.0, 30.0) Romberg uni Training 22.7 (15.3, 29.9) 27.6 (25.3, 30.0) **† eyes open Non-training 16.3 (6.7, 30.0) 15.3 (5.6, 30.0) Tandem Training 28.8 (30.0, 30.0) 29.3 (30.0, 30.0) eyes open Non-training 25.5 (22.1, 30.0) 24.4 (16.5, 30.0) Romberg bil Training 29.5 (30.0, 30.0) 30.0 (30.0, 30.0) eyes closed Non-training 30.0 (30.0, 30.0) 30.0 (30.0, 30.0) Romberg uni Training 4.3 (2.6, 6.0) 13.3 (6.0, 23.0) **†† eyes closed Non-training 4.0 (2.3, 4.2) 4.5 (2.1, 5.8) Tandem Training 12.4 (5.0, 21.4) 24.4 (17.8, 30.0) **††† eyes closed Non-training 10.0 (6.1, 13.7) 7.8 (3.2, 11.4) ** p < 0.01 compared with baseline value. † p < 0.05, †† p < 0.01 and ††† p < 0.001 compared with NONTR. bil = bilateral, uni = unilateral. In the study reported by Fisher and colleagues extremity muscle strength, agility, balance and (1991), the most important improvements were coordination of bilateral knee OA patients. The observed in perceived pain during walking, standing, program comprised lower leg progressive repetitive rising from a chair and climbing stairs with values of exercises, flexibility exercises of the lower 30 and 10% for 16 and 8 weeks training extremities, coordination and balance exercises. respectively. In contrast these parameters improved From baseline to 3 months, only perceived pain at 62.5 ± 14.3%, as a total score, after training in the night and muscle strength showed significant present study. In a further study Fisher and improvements. Time to walk 20-m, stair climbing, colleagues (1993) investigated the effects of a postural stability and balance were unchanged by 3 rehabilitation program, which included stretching months of training. In addition, they observed an and resistance exercise 3 days a week for 3 months, increased number of knees with effusions after on functional performance and perceived pain in intervention and they reported that the intervention subjects with knee OA. Improvements in function led to an increase in the disease. Lack of and perceived pain were greater in the present study proprioceptive sensation probably causes altered gait compared with a 3 month program (Fisher et al., and non-physiological joint loading - which results 1993). in disability and further symptoms in OA patients Rogind et al. (1998) have investigated the (Barret et al., 1991; Stauffer et al., 1977). Stauffer et effects of a physical training program, employed al. (1977) suggested that deterioration in twice a week for 3 months, on general fitness, lower proprioception might be a major factor, and that the Table 9. Isometric peak torque (Nm) of patients at knee angels of 30° and 60°. Data are means (interquartile range). Baseline After 6 weeks Training 59 (42, 71) 71 (50, 90) ** 30° Non-training 60 (49, 69) 61 (52, 75) Training 76 (51, 100) 103 (66, 125) ** 60° Non-training 90 (73, 111) 90 (71, 112) Training 53 (40, 61) 59 (37, 81) 30° Non-training 44 (30, 64) 50 (39, 65) * 60° Training 41 (29, 49) 49 (32, 66) * Non-training 41 (25, 69) 41 (35, 53) * p < 0.05 and ** p < 0.01 compared with baseline value. QUA = quadriceps, HAM = hamstring. HAM QUA 598 Sekir and Gür abnormal gait is an effort to maximize significantly different compared with our control proprioceptive input. Hu and Woollacott (1994) group. When compared with Hurley’s results, our suggested that general exercise programs are less patients had a similar improvement in functional effective than programs that target a specific system performance time and more than double the (e.g. visual, vestibular, somatosensory) that improvement in joint position sense and pain score functions to maintain balance. The present study after training. The patients in the present study provides evidence that short-term proprioceptive/ performed only proprioceptive and balance exercises balance training improves balance and and recorded large improvements. Thus compared proprioception in older OA patients, as emphasized with more sophisticated programs (Hurley and Scott, by Hu and Woollacott (1994). Therefore, the reason 1998) for improving function in OA – it may be for the failure of many exercise studies including beneficial to target improved balance and Rogind and co-workers (1998) to elicit significant coordination (present study). changes may be the lack of specificity in the training Barrett et al. (1991) compared knee joint program. position sense among 81 normal, 45 OA patients and When we compared the results of the present 21 patients who had replacement surgery. In this study with previous studies, which used traditional/ earlier study the volunteers’ legs were moved aerobic and strength exercises for OA (Beals et al., passively in the range 0 to 30º in 10 different 1985; Chamberline et al., 1982; Fisher et al., 1991; predetermined positions of flexion - and the 1993; Minor et al., 1989), the functions and individual was subsequently asked to represent the symptoms of the patients in these earlier studies did perceived angle of flexion on a visual analogue not improve as markedly as similar measures found model. Average JPS error score was 5º in the healthy in the present study. In the present study, the most and 7º in OA patients. In the present study the active marked change was observed in descending and error score for 20º knee flexion angle was 8.8±4.4º climbing stairs times with values of 21 and 15% for patients with a mean age of 60 years and respectively. These results are particularly important improved to 5.5±2.3º with training. Therefore, it considering that the ability to descend and ascend may be speculated that knee position sense can be stairs is impaired in OA compared with healthy improved in OA after training to a level attained by subjects (Hurley et al., 1997). In addition, it should age-matched healthy subjects. be noted that the patients in TR suffered less Daily activities like walking, ascending or perceived pain in their knee even though they moved descending stairs are weight bearing; knee faster during the tests after training. Our results also proprioception was generally tested under a non- show that improvements in functional capacity and weight bearing condition in these previous perceived knee pain are not necessarily associated investigations. In the present study, knee joint with improved knee strength. proprioception was investigated under a weight Hurley and Scott (1998) investigated the bearing condition. Petrella et al. (1997) investigated effects of an exercise regime on quadriceps strength knee joint proprioception under weight bearing and proprioceptive acuity and disability in patients condition in young volunteers and in physically with knee OA. The exercises included isometric active and sedentary older volunteers. They reported quadriceps contractions, a static exercise cycle, that the mean active angle reproduction errors at the isotonic knee exercise using therapeutic resistance test angles that ranged 10 to 60° of knee flexion bands, functional (sit-stand, steps, step-down) and were 2.0 ± 0.5º, 3.1 ± 1.1º and 4.6 ± 1.9º for young, balance/co-ordination exercises (unilateral stance physically active and sedentary older people and balance boards). Following 5 weeks of training, respectively. Bullock-Saxton et al. (2001) also they found that quadriceps strength, joint position measured the joint position reproduction error under sense, aggregate functional performance time and full weight bearing condition in healthy young (20- Lequesne Index (as a subjective assessment of 35 years old), middle-aged (40-45 years old) and perceived knee pain) improved significantly in the older (60-75 years old) subjects. They reported exercise group by 36.3, 12.9, 13.7 and 31.8% values of 1.9 ± 0.8º, 2.0 ± 0.7º and 2.2 ± 0.9º, for the respectively. These values were significantly three groups respectively, for a test angle between different compared with a control group - except 20 and 35º of knee flexion. In our subjects it was 3.0 joint position sense. In the present study, average ± 1.5º and 3.4 ± 1.5º at the angles of 15° and 30° of joint position sense for active and passive tests, total knee flexion, respectively, before training and time for functional tests and total visual analog score improved to 1.3 ± 0.6º and 1.5 ± 0.6º, respectively, (VAS) for perceived knee pain during daily after training. Therefore knee position sense under activities improved 32.8, 38.2, 12.9 and 62.5% weight bearing condition can be improved in OA to following training. Again these changes were Proprioceptive exercises in knee osteoarthrosis 599 the level of young healthy subjects using the training disability in our patients may, at least in part, relate program described herein. to factors other than muscle strength. The balance test performed ‘eyes open’ and ‘eyes closed’ reflects the reorganization of the CONCLUSIONS different components of postural control. In the elderly, visual sensors are of major importance in The findings of the present study suggest that using a postural control, while vestibular and proprioceptive pure proprioceptive/balance exercise program it is afferents are less used (Gauchard et al., 1999; Perrin possible to improve functional capacity, postural et al., 1999). Hence the ‘eyes open’ and ‘eyes control and decrease perceived knee pain in patients closed’ data obtained in the present study allow an with bilateral knee osteoarthrosis. The exercise regime appreciation of the respective “weight” of the used in the present study was as effective as previous various balance sensors and their interactions in studies (O’Reilly et al., 1999; Fisher et al., 1991; postural and motor control. In the present study, we Fisher et al., 1993; Beals et al., 1985; Chamberline et observed that ‘eyes closed’ Romberg unilateral and al., 1982; Minor et al., 1989), but of much shorter Tandem test times were improved 208 and 164% duration and utilized unsophisticated, inexpensive respectively in TR. The magnitude of these changes, equipment which is available in most physiotherapy even though the ‘eyes closed’ condition was very departments. Therefore, the incorporation of this difficult for this cohort, suggests that the training exercise program into clinical practice is readily program used in the present study is clinically feasible. important for balance. It can be also speculated that, in order to retain a proper balance with ‘eyes REFERENCES closed’, our TR might have compensated for the visual deprivation by an increased usage of other Altman, R., Asch, E. and Bloch, D. 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(1998) The KEY POINTS effects of a physical training program on patients with osteoarthritis of the knees. Archives of Physical Medicine and Rehabilitation 79, 1421- • It is possible to improve postural control, 1427. functional capacity and decrease perceived Stauffer, R.N., Chao, E.Y.S. and Gyory, A.N. (1977) knee pain in patients with bilateral knee Biomechanical gait analysis of the diseased knee osteoarthrosis with a pure proprioceptive/ joint. Clinical Orthopaedics 126, 246-255. balance exercise program used in the present Swanik, C.B., Rubash, H.E., Barrack, R.L, and Lephart, study. S.M. (2000) The role of proprioception in patients • The exercise regime used in the present study with DJD and following total knee arthroplasty. In: was as effective as previous studies, but of Proprioception and neuromuscular control in joint much shorter duration and utilized stability. Eds: Lephart, S.M. and Fu, F.H. United States: Human Kinetics. 323-339. unsophisticated, inexpensive equipment which Topp, R., Mikesky, A., Wigglesworth, J., Holt, W.Jr. and is available in most physiotherapy departments. Edwards, J.E. (1993) The effect of a 12-week • Therefore, the incorporation of this exercise dynamic resistance strength training program on program into clinical practice is readily gait velocity and balance of older adults. feasible. Gerontologist 33, 501-506. WMADH (2000) World Medical Association Declaration of Helsinki. The Journal of the American Medical Dr. Hakan Gür Association 20, 3043-3045. Sports Medicine Department, Faculty of Medicine, Uludag Univeristy, 16059 Bursa, Turkey. AUTHORS BIOGRAPHY Ufuk SEKIR Employment Ass. Prof. Sports Medicine Department, Faculty of Medicine, Uludag Univ., Bursa, Turkey. Degree MD Research interests Proprioception, ACL rehabilitation, osteoarthritis and exercise. E-mail: ufuksek@hotmail.com Hakan GÜR Employment Prof., Sports Medicine Department, Faculty of Medicine, Uludag Univ., Bursa, Turkey. Degree MD, PhD Research interests Isokinetic, menstrual cycle and exercise, circadian variations, ACL rehabilitation, osteoarthritis and exercise, smoking and exercise, ageing and exercise. E-mail:hakan@uludag.edu.tr 602 Sekir and Gür APPENDIX Figure 1. Illustration of the exercises. To improve balance and proprioception eleven exercises were performed in the following order (see Figure 1): 1) Walk forward through 6 boxes (50cm x 50cm) staircase (17 cm high and 23 cm wide), -up and - on one-foot (in-in-out to right-in-in-out to left). down. 2) Stair-up and -down a regular 3 steps staircase 6) Perform a one-legged stand with one foot (17 cm high and 23 cm wide). raised to the back (the non-weight bearing knee flexed at 90°). Try to maintain the position for a 3) Stand with feet approximately shoulder width minimum of three seconds. The long-term goal is apart and extend arms out slightly forward and to decrease the need for balance support and to lower than the shoulder. Lift both heels off the hold the position for 10 seconds. However, as floor and try to hold the position for 10 seconds. necessary, the hands are allowed to contact the Followed by climbing a regular 3 steps staircase support apparatus (a standard chair). Followed by (17 cm high and 23 cm wide), -up and -down. climbing a regular 3 steps staircase (17 cm high and 23 cm wide), -up and -down. 4) Standing with feet side by side, hold arms in the same position as described in the previous 7) Perform the same exercise as above, but raise exercise. Place one foot on the inside of the one foot to the front (the non-weight-bearing knee opposing ankle and try to hold the position for 10 flexed and lifted approximately as high as the hip). seconds. Followed by climbing a regular 3 steps Followed by climbing a regular 3 steps staircase staircase (17 cm high and 23 cm wide), -up and - (17 cm high and 23 cm wide), -up and -down. down. 8) Walk heel-to-toe along a 3m line marked on a 5) Repeat the exercise 3 with hands behind the medium-density polyfoam mat. back. Followed by climbing a regular 3 steps Proprioceptive exercises in knee osteoarthrosis 603 9) Rising from a standard chair (4 times) without 11) With the knee straight but not hyperextended, arm support. execute single (relatively small) leg raises to the front, then back. Continued alternating front to 10) Walk heel-to-toe along a 3-m line marked on a back. medium-density polyfoam mat. Patients performed 11 different exercises (above) once during weeks 1 and 2, twice during weeks 3 and 4 and three times during weeks 5 and 6. In addition, subjects were instructed to stand in 6 different conditions for static exercises (exercise 2, 3, 4, 5, 6 and 11) as follows: 1. Week 1: on a firm surface, eyes open, head 4. Week 4: on a firm surface, eyes closed, head neutral. tilted back. 2. Week 2: on a firm surface, eyes closed, head 5. Week 5: on a foam surface, eyes open, head neutral. neutral. 3. Week 3: on a firm surface, eyes open, head 6. Week 6: on a foam surface, eyes closed, head tilted back. neutral.