Reporter: Chao-jung Hsieh Supervisor: Sai-wei Yang Date: 2007/10/29 Role of muscle strength affecting dynamic balance ability for subjects with knee osteoarthritis Reporter: Chao-jung Hsieh Supervisor: Sai-wei Yang Date: 2007/10/29

Outline Introduction Materials and methods Knee osteoarthritis Literature review Materials and methods Participants Experimental procedure

Introduction Knee osteoarthritis (OA) is one of major problems in the elderly Knee OA, rather than any other joint, is more likely to cause disability Davis 1998 In Taiwan, the prevalence of OA ranges from 5.1% to 6.3% Chou et al 1994 It is defined as a degenerative condition that lead to joint symptoms and signs which is associated with defective integrity of articular cartilage, in addition to related changes in the underlying bone and at the joint margins

Classification of osteoarthritis The Kellgren-Lawrence scale The severity of articular cartilage changes of OA by radiographs Patellofemoral joint space narrowing Presence of osteophytes Kellgren-Lawrence Scale No osteophytes 1 Doubtful osteophytes 2 Minimal osteophytes, possible narrowing, cysts, and sclerosis 3 Moderate or definite osteophytes with moderate joint space narrowing 4 Severe with large osteophytes and definite joint space narrowing

Knee Osteoarthritis 71% ~ 91% of total joint load is transmitted through the medial compartment of knee joint Maly 2002 The symptoms include: Joint stiffness Pain Deterioration of coordination

Balance Static balance Dynamic balance DeOreo 1980 Evaluation / Training of dynamic balance is effective for improving the postural control ability Shumway-Cook 2000 Steadiness- trajectory of center of pressure Symmetry- ratio of weight-bearing Dynamic stability- functional tests Niam 1999

Postural control Difficulty in squatting, kneeling, and rising from a chair Avoidance of pain associated with limb loading and decline in postural control ability Bennell 2003; Na 2003

Postural control Individuals with knee OA demonstrate Significantly more postural sway than the age-matched group Wegener 1997; Kul-Panza 2006 Balance deficits in clinical tests Hinman 2002

Muscle control Robbins 1989 Effective control of balance rely not only accurate sensory input but also a timely response of strong muscles Subjects with knee OA revealed Quadriceps are weak with delayed activation when walking Birmingham 2001 The lower extremity muscular strength is reduced Kaufman 2001 Increased hamstring muscle activation while executing activities of daily life Hortobagyi 2005 Knee and hip weakness are related to poor balance and a greater risk of falling Robbins 1989

Purpose and dynamic balance among subjects with knee OA To investigate the relationship between muscle strength and dynamic balance among subjects with knee OA To determine the role that severity of knee pain play in the ability to maintain balance

Materials and methods Participants Eligibility criteria Thirty subjects with bilateral knee osteoarthritis, as well as a group of thirty controls Eligibility criteria Age over 40 years old No other disease of lower extremity Exclusion criteria Receiving any surgeries of lower extremity Having severe medical illnesses that affected the subject’s ability to perform sustained activities

Experimental procedure Basic data measurements Dynamic balance Muscular strength Knee pain

Basic data measurements Descriptive data Age Gender Height Weight Physical activity level Health condition Berg Balance Score (BBS)

Dynamic balance Dynamic perturbation system (Stewart platform) Sinusoidal angular rotation with 10°at 0.3Hz/0.6Hz Antonio 2000; Yang 2001 The footscan system (Rsscan International Co., Belgium)

Dynamic balance Pitch Row Total travelled way Ellipse area Center of pressure (CoP) Total travelled way Ellipse area Maximal AP/ML distance Ratio of weight bearing Pitch Row

Muscular strength Isokinetic dynamometer Frontal plane Sagittal plane Hip abduction/adduction Ankle eversion/inversion Sagittal plane Knee flexion/extension Ankle plantar-flexion/ dorsi-flexion Electromyography

Muscular strength Peak torque Power Latency of muscle firing N-M Time Whipple 1987; Toole 2000; Carmeli 2002 Hocherman 1984

Knee pain Visual analogue scale (VAS) Lequesne index Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)

Flow chart Statistical analysis Experimental procedure Participants Normal group OA group Data measurements Descriptive data Questionnaires Experimental procedure Dynamic balance Muscle strength Statistical analysis Inform consent

Clinical application Treatments – strengthening exercise

References Whipple RH, Wolfson LI, Amerman PM(1987)The relationship of knee and ankle weakness to falls in nursing home residents: An isokinetic study. JAGS. 35:13-20 Wegener L, Carolyn K, Nichols D(1997)Static and dynamic balance responses in persons with bilateral knee osteoarthritis. JOSPT. 25:13-18 Jadelis K, Miller ME, Ettinger WH and Messier SP(2001)Strength, balance, and the modifying of obesity and knee pain. J Am Geriatr Soc. 49:884-891 Yelin EH, Felts WR. (1990) A summary of the impact of musculoskeletal conditions in the United States. Arthritis Rheum, 33:750-5 Birmingham TB, Kramer JF, Kirkley A, et al.(2001)Knee brace for medial compartment osteoarthritis: effect on proprioception and postural control. Rheumatology, 40:285-289 Kul-Panza E, Berker N(2006) Pedobarographic findings in patients with knee osteoarthritis . Am J Phys Med Rehab,85:228-233 Jadelis K, Miller ME, Ettinger WH, et al.(2001) Strength, balance and the modifying effects of obesity and knee pain: results from the Observational Arthritis Study in Seniors (OASIS). J Am Geriatr Soc,49:884-891

Thanks for your attention

Center of pressure Center of pressure (CoP) Trajectory of body center of mass over the support Movements of CoP are indicators of stability Alexander 1994

Displacements of CoP Anterior/posterior direction Ankle plantar/dorsi flexors Medial/lateral direction Hip abductors Ankle evertors/invertors Winter 1987