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What is Osteoarthritis?

Osteoarthritis (OA) is a progressive disease in the joints affecting nearly one third of the older population, with future estimates indicating a significant rise in occurrences for the ageing population. Frequently reported symptoms of osteoarthritis include joint pain, stiffness, loss of physical function, and muscle weakness, among others. Conventional management for OA includes physiotherapy (Day, Heywood, & Hinman,2007).

The practical use of hydrotherapy has been prevalent for approximately 16 centuries. Over the last hundred years, significant advances have been made in treatments using hydrotherapy. Musculoskeletal therapy applications of hydrotherapy include therapeutic and exercise activities in a heated pool. The buoyancy in water reduces weight placed on pain-affected joints, and water turbulence can be used as resistance as an alternative to weights. The hydrotherapist can adjust the pressure and temperature of the water to further assist with pain and swelling (Day et al., 2007).

water therapy exercise for osteoarthritis


This study was designed to address the limitations of previous studies, where little consideration was given to hydrostatic or hydrodynamic principles, thus reducing the potential benefits for the participants. Moreover, previous studies typically did not evaluate a sample based specifically on knee or hip osteoarthritis alone. The study aimed to use a functional progressive intervention on their groups in a controlled trial with intention-to-treat analysis, using the properties of water to optimise outcomes.

Through this 6-week programme, the objective was to measure improvements in pain and physical function of participants with OA in their hip, knee, or both. The study would compare these results against a control group with no aquatic physiotherapy. Furthermore, the study would determine if participants continued a therapy regimen independently after the initial 6-week programme, and a follow up to see which benefits were maintained during another 6 weeks later (Day et al., 2007).

The study searched for participants that were over 50 years old, with hip or knee osteoarthritis. Advertisements were placed in several venues to recruit participants, including libraries, doctors’ offices, orthopaedic clinics, and within both print and radio media. The study excluded potential participants that showed specific contraindications, such as significant back pain, recent joint injections, recent surgery, lower-limb joint replacement, and those that were unable to safely enter and exit a pool.

312 volunteers registered and were screened, of which 71 were selected as fitting the criteria and were subsequently enrolled in the study. An intervention group of 36 was established, with a control group of 35 also created with a plan that they would receive the aquatic treatment after the study in exchange for simply continuing their normal routine for the 6-week process. A sample size of 71 participants was selected to achieve a statistical significance level of 5% to detect a difference in pain of 2 cm (discussed later in the outcomes), allowing for participants who may drop from the programme (Day et al., 2007).

Immediately before the treatment, participants were assessed based on the study's standards. They were assessed again immediately after the 6 weeks, and again at 12 weeks. This protocol would allow assessment of which benefits were maintained in the long term, as well as the likelihood of continued independent aquatic therapy by the participants (Day et al., 2007).

The intervention group underwent 6 weeks of exercises in a hydrotherapy setting, provided twice weekly in sessions that were approximately one hour each. With a maximum of six participants per session, the therapist emphasised quality of movement while working on balance and strength. The participants were tracked and individual progression was determined by the therapist. During this six-week programme, the participants were asked to keep a log of their sessions. Following the study, they were encouraged to continue independent aquatic therapy twice weekly. In addition, the participants were instructed to continue their usual medication for the entirety of the 12-week period (Day et al., 2007).

hydrotherapy for man with arthritis


The outcomes that were measured from this study include participant-perceived changes in pain and physical function, muscle strength, balance, and gait. Using a visual analogue scale measured in 1 cm increments, these metrics were rated by the participants and interpreted by the team conducting the study. While rating pain, a scale of 1-5 was used to show improvement, 5 indicating the greatest improvement. To test for physical function, the participants were asked to stand up from a sitting position, walk 3 metres, and return to the chair while walking at their own pace (Day et al., 2007).

Muscle strength was measured as peak strength, assessed three times and the highest score recorded. Balance was tested by having the participant stand barefoot on the affected limb, and move their other foot up to a 7.5 cm step and back as many times as possible for 15 seconds. For the balance test, the individuals were not required to shift body weight, and those completing a higher number of steps were scored as having better balance. To test gait, participants were evaluated on how far they could walk within a 6-minute time-frame. They walked back and forth over a 50-metre stretch, and their total distance was measured and recorded (Day et al., 2007).


The primary results of this study indicated that pain from movement was reduced by 33% from the baseline assessment, demonstrating significantly less pain at 6 weeks for the intervention group than the control group. Seventy-two percent of the intervention participants reported a global improvement in pain, compared to only seventeen percent in the control group. For global improvements in physical function, seventy-five percent of the intervention group responded positively, while seventeen percent of the control group participants responded the same (Day et al., 2007).

At the 6-week mark, intervention participants reported significantly less pain. Hip muscle strength and quality of life were rated as significantly greater as well. During the follow-up six weeks later, 84% of participants reported that they had continued to seek independent aquatic physical therapy. 45% of the group attended one or two times per week, and another 15% attended 2 or 3 times per week. The rated scores at the 12-week mark showed that the overall ratings were generally unchanged from scores obtained at 6 weeks, indicating that benefits of the programme were maintained in the short term, but with continued therapy, decreased pain and better physical function would persist (Day et al., 2007).


With a relatively small sample size, it’s difficult to specifically say that aquatic therapy is superior to similar therapy based on land. The study identified limitations, including the lack of placebo, which yielded a single-blind design and therefore may have skewed the results. The chronic nature of osteoarthritis also warrants longer evaluation periods for further examination and statistical testing. In this study, participants were only using their own body weight and the resistance of the water. It was noted that additional items such as swim fins and floatation devices may have been used to increase resistance and improve strength and muscle functions (Day et al., 2007)

In a clinical setting, the results from this study can be applied by making reference to the time-line for decrease of pain in a patient. In practice, standard physical therapy may prove to be too physically straining, in which case, a physical therapist assistant could discuss the option of aquatic therapy to the physical therapist, specifically noting the decreased stress on osteoarthritic joints, and the combination of turbulence and water temperature in their beneficial manner in regards to weight bearing. Once on a plan for aquatic therapy, the physical therapist assistant could have a better understanding of expectations for results in the pain management sector of the treatment plan as designed by the physical therapist.


Day, A. R., Heywood, S. F., & Hinman, R. S. (2007). Aquatic physical therapy for hip and knee osteoarthritis: Results of a single-blind randomized controlled trial. Physical Therapy, 87(1), 32+. Retrieved from|A157267508&v=2.1&u=lirn09099&it=r&p=PPNU&sw=w&asid=47d97cd364b4dbe1fe318cd8dee9b374

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