Research Review By Dr. Kent Stuber©

Date Posted:

June 2009

Study Title:

Long-term effects of kinesthesia/balance and strengthening exercises on patients with knee osteoarthritis: A one-year follow-up study.


Diracoglu, D, Baskent A, Celik A, Issever H, Aydin R.

Author's Affiliations:

Departments of Physical Medicine and Rehabilitation and Public Health, Istanbul Medical Faculty, Istanbul University.

Publication Information:

Journal of Back and Musculoskeletal Rehabilitation 2008; 21: 253-262.

Background Information:

Osteoarthritis (OA) is cited as the most common joint disease world-wide, with the knee being the most frequently involved joint. Fitness professionals commonly encounter clients with knee OA and they can be difficult to manage. Some possible risk factors for knee OA include increasing age, being female, previous trauma or work-related injury, heredity, and obesity. Knee OA has been shown to alter proprioceptive sense tremendously. Among the numerous possible therapies for knee OA, strengthening exercises are one of the most commonly recommended, and there is support for this intervention in the literature.

To date there is little information as to whether balance/kinesthetic exercises aid standard strength exercise regimens or are more beneficial than such programs, and whether benefits from these exercises are lasting. This study compared strength training with or without balance/kinesthesia exercise in the management of knee OA.

Pertinent Results:

  • there were no statistically significant differences between groups at baseline in either outcome measures or demographic factors
  • both the strength only (SO) group and the group performing kinesthesia and strengthening exercises (KS) saw significant improvements in all outcome measures after completing their exercise regimens
  • several outcome measures (SF-36 vitality, WOMAC-total, Lequesne index, Beck Depression Inventory) were significantly better in the KS group after 8 weeks, and there were several other outcome measures (WOMAC-pain, WOMAC-stiffness, WOMAC-physical function, WOMAC-total) where the KS group was significantly better after 1 year
  • there were 5 drop outs from the SO group and 1 from the KS group
  • overall 60 patients completed the 8 week exercise program (28 in SO and 32 in KS)
  • 45 patients completed the 1 year follow-up (17 in SO and 28 in KS)
  • 78% of the KS group and 88% of the SO group indicated that they completed their exercises regularly after one year

Clinical Application & Conclusions:

The authors concluded in their abstract that over the course of one year, kinesthesia and balance exercises appear to be superior to strengthening exercises only on WOMAC parameters in women with mild-to-moderate knee OA. In the body of the paper they more correctly conclude that a combination of strengthening exercises with kinesthesia/balance exercises provided significantly better WOMAC scores than strengthening exercise alone (underscoring the importance of always trying to read the entire paper!).

It would behoove fitness professionals to strongly consider adding kinesthesia/balance exercises to the exercise recommendations that they make to their clients with mild-to-moderate knee OA. Many of the exercises in the kinesthesia/balance exercise program in this study would not require any special equipment, making them readily applicable in a training environment and appropriate for a dynamic warm-up. A brief description of some of the initial strength and kinesthesia/balance exercises used in this study appear below. These low-tech exercises can easily be performed in clinical, gym, or home settings.

5 minute stationary bike without resistance
Active ROM exercises
Stretching of hamstrings and quadriceps
Isometric quadriceps exercises (all strength exercises were initiated as 40% of 1 rep maximum; 3 sets of 8 reps; progressed to70% of 1 rep max ; 2-3 minutes of rest between sets)
Isometric hamstring exercises
Isometric hip abductor and adductor exercises
Knee terminal extension

Rhomberg exercise (standing with eyes closed) – on hard ground and on a mat
25 m backwards walk
25 m heel walk
25 m toe walk
25 m eyes closed walk
30 second 1-legged stand
1 legged leaning forward, backward, and to sides – eyes open and closed
Sitting down and standing up from a high chair slowly.

Study Methods:

This study was performed under controlled conditions. There was assessor blinding and informed consent was obtained from patients before entering the study. Ethical approval for the study was obtained. 66 women with mild-to-moderate knee OA were assigned to 1 of 2 groups (they were placed into the groups according to order of admission). Clinical and radiological factors were used in the diagnosis of the OA, with a six-point criteria list being set for admission into the study.

The Kinesthesia-Strengthening group (KS) performed kinesthesia/balance exercises along with strengthening exercises. The Strengthening only group (SO) only performed strengthening exercises. Patients performed the exercises in a clinical setting 3 times a week for 8 weeks in groups under physiotherapist supervision. After the 8 weeks they were encouraged to continue the exercises at home.

Outcome measures included the WOMAC (for OA health status: assesses pain, stiffness, and physical functional status), SF-36 (to assess overall health status), Lequesne algofunctional index (for knee OA), and the Beck Depression Inventory (assesses depression level). Patients were assessed at baseline, after the 8 week supervised exercise program, and 1 year after completion of the exercise program. Descriptive statistics, paired t-tests and two-way ANOVA were used in the analysis.

Study Strengths / Weaknesses:

This article has several strengths including the use of numerous valid and reliable outcome measures. The 1-year follow-up is also an important strength, as is the blinding of assessors and the fact that the 2 exercise groups were largely equal at baseline. By using the strengthening exercise program in both groups, it could be seen how much of an additional effect the kinesthesia/balance exercises had.

In terms of drawbacks or weaknesses in this study, the first and most glaring is that this was not a true RCT – subjects were allocated to group according to order of enrollment, this is a suboptimal means of group assignment, but as mentioned above the groups were very similar at baseline so this was not a fatal flaw to this study. In addition, the study was only single blinded (the assessors were blinded) while the subjects were not, so there could have been interaction from them knowing which group they were in as well as potential for the Hawthorne effect to take place (a definition of the Hawthorne Effect is where subjects in a study may improve their performance or behavior, not because of any specific condition being tested, but because of all the attention they receive or simply being involved in the study).

The measurements only took place at baseline, the end of the 8 week exercise programs, and at one year follow-up. There was no measurement period between the 8 week and one year later measurements – adding a three and/or six month measurement may have yielded additional useful data. A one year follow-up, while an achievable and common length of time (and a very nice number), is not truly long-term when one considers the chronic nature of OA – having a three or five year follow-up would be even more useful.

The study did not have any assessment of subject strength or proprioception. It would have been beneficial to have a physical measure of subject progress as the outcome measures employed were all paper-based. From a compliance standpoint, the study required all of the subjects to complete 24 exercise visits in the 8 week period and this could be very difficult to achieve in clinical practice. Finally it might have been useful for the study to have a kinesthesia/balance exercise only group for true comparisons to the strength group.

Additional References:

OA of the knee is one of the most studied of all musculoskeletal disorders. There are some very strong systematic reviews on exercise for knee OA, but they all highlight the need for additional research given the prevalence of this condition and the advancing age of the population in the Western world.
  1. Fransen M, McConnell S. Exercise for osteoarthritis of the knee. Cochrane Database Syst Rev 2008; (4): CD004376.
  2. Lange AK, Vanwanseele B, Fiatarone Singh MA. Strength training for treatment of osteoarthritis of the knee: a systematic review. Arthritis Rheum 2008. 59(10): 1488-94.