Muscle activation features of the osteoarthritic knee with patellar lateral subluxation

OBJECTIVE The aim of the study was to compare the muscle activation feature of vastus medialis obliquus (VMO) and vastus lateralis (VL) between the osteoarthritic knee patients with patellar lateral subluxation (Group 1B) and without patellar lateral subluxation (Group 1A). METHODS Isokinetic muscle strength of the knee extensor was evaluated using a CYBEX NORM dynamometer with angular velocities of 80, 120 and 240 degrees/second (°/sec) respectively, contraction activities of VMO and VL muscle were recorded with synchronized surface electromyography (sEMG). Age-matched healthy subjects were recruited and served as control group (Group 2). The VMO/VL ratio of EMG between Group 1A, Group 1B and Group 2 were compared. RESULTS The peak torque in Group A was 40.7 ± 12.9, in Group B was 39.6 ± 12.9 and in Group C was 60.2 ± 9.5 respectively at 80°/sec angular velocity (p < 0.01). There were no significant difference between Group 1A and Group 1B in the three trial of tested velocities (p > 0.01). The sEMG ratios of VMO/VL of Group 1B calculated at angular velocities of 80/sec was 0.769 ± 0.15, 120°/sec was 0.818 ± 0.22 and 240°/ sec was 0.850 ± 0.22, all those were lower than Group 1A and Group 2 (p<0.01). CONCLUSION Musculature imbalance of VMO and VL may explain the different muscle activation pattern in osteoarthritic knee patients with and without patellar lateral subluxation.

[1]  T. M. Owings,et al.  Motor Control of the Vastus Medialis Oblique and Vastus Lateralis Muscles is Disrupted during Eccentric Contractions in Subjects with Patellofemoral Pain , 2002, The American journal of sports medicine.

[2]  L. White,et al.  Imaging of patellofemoral disorders. , 2004, Clinical radiology.

[3]  John V. Basmajian,et al.  Electrode placement in EMG biofeedback , 1980 .

[4]  C. Powers,et al.  Rehabilitation of patellofemoral joint disorders: a critical review. , 1998, The Journal of orthopaedic and sports physical therapy.

[5]  R. Dussault,et al.  IMAGING OF THE KNEE: Current Status , 1997 .

[6]  M. Griffin,et al.  Patterns of knee arthrosis and patellar subluxation. , 1994, Clinical orthopaedics and related research.

[7]  P. Keblish,et al.  Patellar resurfacing or retention in total knee arthroplasty. A prospective study of patients with bilateral replacements. , 1994, The Journal of bone and joint surgery. British volume.

[8]  K. An,et al.  The influence of weakness in the vastus medialis oblique muscle on the patellofemoral joint: an in vitro biomechanical study. , 2000, Clinical biomechanics.

[9]  M. Lequesne.  The algofunctional indices for hip and knee osteoarthritis. , 1997, The Journal of rheumatology.

[10]  Michael T. Gross,et al.  Comparison of Vastus Medialis Obliquus:Vastus Lateralis Muscle Integrated Electromyographic Ratios Between Healthy Subjects and Patients with Patellofemoral Pain , 1991 .

[11]  F. Awiszus,et al.  Neuromuscular quadriceps dysfunction prior to osteoarthritis of the knee , 2004, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[12]  L. Sharma,et al.  Epidemiology of osteoarthritis: an update , 2006, Current opinion in rheumatology.

[13]  Margareta Nordin,et al.  Basic Biomechanics of the Musculoskeletal Systm , 1989 .

[14]  Tomoyuki Saito,et al.  Provoked anterior knee pain in medial osteoarthritis of the knee. , 2003, The Knee.

[15]  C. Cooper,et al.  Radiographic patterns of osteoarthritis of the knee joint in the community: the importance of the patellofemoral joint. , 1992, Annals of the rheumatic diseases.

[16]  R. Burdett,et al.  An electromyographic study of vastus medialis oblique and vastus lateralis activity while ascending and descending steps. , 1998, The Journal of orthopaedic and sports physical therapy.

[17]  Ling Xu,et al.  Quadriceps weakness and its relationship to tibiofemoral and patellofemoral knee osteoarthritis in Chinese: the Beijing osteoarthritis study. , 2004, Arthritis and rheumatism.

[18]  D. Felson,et al.  Are risk factors for patellofemoral and tibiofemoral knee osteoarthritis different? , 1996, The Journal of rheumatology.

[19]  H. Schumacher,et al.  Osteoarthritis of the knee: isokinetic quadriceps exercise versus an educational intervention. , 1999, Archives of physical medicine and rehabilitation.

[20]  A. C. Merchant,et al.  Roentgenographic analysis of patellofemoral congruence. , 1974, The Journal of bone and joint surgery. American volume.

[21]  Jh. Kellgren.  Radiological assessment of osteoarthrosis , 1957 .

[22]  L. Ryd,et al.  Patellar and Quadriceps Mechanism , 2003 .

[23]  M. Callaghan,et al.  Quadriceps atrophy: to what extent does it exist in patellofemoral pain syndrome? , 2004, British Journal of Sports Medicine.

[24]  Michael Doherty,et al.  Quadriceps weakness in knee osteoarthritis: the effect on pain and disability , 1998, Annals of the rheumatic diseases.

[25]  Henry L. Lew,et al.  Vastus medialis obliquus and vastus lateralis activity in open and closed kinetic chain exercises in patients with patellofemoral pain syndrome: an electromyographic study. , 2001, Archives of physical medicine and rehabilitation.

[26]  Docteur Paul G. J. Maquet,et al.  Biomechanics of the Knee , 1984, Springer Berlin Heidelberg.

[27]  Jacquelin Perry,et al.  Electromyography of the Quadriceps in Patellofemoral Pain with Patellar Subluxation , 2003, Clinical orthopaedics and related research.

[28]  L. Sharma,et al.  Quadriceps Strength and Osteoarthritis Progression in Malaligned and Lax Knees , 2004, Annals of Internal Medicine.

[29]  J. Kellgren,et al.  Radiological Assessment of Osteo-Arthrosis , 1957, Annals of the rheumatic diseases.

[30]  C. Powers.  Patellar kinematics, part I: the influence of vastus muscle activity in subjects with and without patellofemoral pain. , 2000, Physical therapy.

[31]  E M Braunstein,et al.  Reduced quadriceps strength relative to body weight: a risk factor for knee osteoarthritis in women? , 1998, Arthritis and rheumatism.

[32]  H. Labelle,et al.  The abnormal lateral patellofemoral angle: a diagnostic roentgenographic sign of recurrent patellar subluxation. , 1978, The Journal of bone and joint surgery. American volume.