Role of muscle strength affecting dynamic balance ability for subjects with knee osteoarthritis

1. 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

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

3. 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 Introduction

4. Classification of osteoarthritis • The Kellgren-Lawrence scale • The severity of articular cartilage changes of OA by radiographs • Patellofemoral joint space narrowing • Presence of osteophytes

5. 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 Knee Osteoarthritis

6. 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 Balance

7. 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

8. 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 Postural control

9. Muscle control • 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

10. 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 Purpose

11. Participants • 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 Materials and methods

12. Basic data measurements • Dynamic balance • Muscular strength • Knee pain Experimental procedure

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

14. 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

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

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

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

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

19. Inform consent Flow chart

20. Treatments – strengthening exercise Clinical application

21. 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 References

22. Thanks for your attention

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

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