Introduction

Although the effectiveness of resistance training for osteoarthritis is recognized in joints such as the knee and hip, much less attention is paid to smaller joints, such as the hand. Hand osteoarthritis is common in older individuals and may cause symptoms of pain, stiffness, and strength deficits, which may complicate daily activities. Trials examining osteoarthritis of larger joints such as the knee specifically point to resistance training for the first-line treatment. A recent meta-analysis by Goh et al. (2019) showed that high-intensity resistance training had large effect sizes for reducing pain when compared with low-intensity exercises. Unfortunately, the fear of flare-ups may prevent high-intensity resistance training from being used as a first-line treatment. Blood flow restriction training may serve as an alternative for high-intensity resistance training, as exercises are low load, but able to produce significant increases in strength and may provoke less pain during training. The evidence for resistance training for osteoarthritis of the hand is scarce and to fill this gap, this feasibility trial was conducted to open the path for further research.

Methods

A single-blind 3-arm randomized controlled feasibility trial was set up comparing advice plus 6 weeks of high-intensity resistance training, to advice plus 6 weeks of blood flow restriction training to a control group receiving advice only in people with hand osteoarthritis.

Exercises that were performed in both training groups were isometric grip and pinch exercises and isotonic thumb extension and abduction movements. The high-intensity resistance training group trained at 60% of maximum voluntary contraction during the first 2 weeks and at 70% during weeks three to six.

In the blood flow restriction training group the same exercises were done but at a lower intensity of 30% of maximum voluntary contraction in the first two weeks and at 40% from weeks 3-6. While training, participants wore a blood pressure cuff (width: 13.5 cm, length 53 cm) on their exercising arm. The pressure delivered to the arm was individualized at each session and was set to 50% of participants’ arterial occlusion.

Regarding exercise progression, both the blood flow restriction and high-intensity resistance training groups performed two sets of each exercise during the first week, three sets during weeks two to four, and four sets during weeks five and six. Participants in the blood flow restriction group performed 30 repetitions during the first set and 15 repetitions in the following sets. The high-intensity group performed 10 repetitions in each set.

Advice was given to the participants in each group and in the control group through a brochure discussing the definition and cause of osteoarthritis, warning signs, diagnosis, and management options.

Results

Fifty-nine participants were included and randomized over the 3 groups. The results indicate that, although preliminary, adherence to the treatment sessions was good, with 78% in the high-intensity group and 89% in the blood flow restriction group. There was no difference in exercise-induced pain and pain levels were low (median NRS 0/10 in both groups). Flare-ups after treatment were low and occurred in 1.6% and 4% of the training sessions in the blood flow restriction group and high-intensity group respectively. There was only one adverse event in the high-intensity resistance training group, where one participant withdrew from the study after the first training session due to excessive pain. In the blood flow restriction group, no single adverse event was noted.

In the exercising groups, more participants were found to be responding to treatment compared to the control group receiving advice only, although for the high-intensity group, this was not statistically significant. A responder was defined as:

“a patient reporting improvement from baseline in pain or function ≥ 50% and an absolute change of ≥ 2 of 10 points (≥20 of 100 points for FIHOA), or improvement in at least two of the following criteria: reduction in pain ≥ 20% and absolute change ≥ 1 of 10 points, functional improvement ≥ 20% and absolute change ≥ 10 of 100 points, improvement in patient’s global assessment ≥ 20% and absolute change ≥ 1 of 10 points.”

The FIHOA was chosen to calculate the number of responders because it was specifically created for hand OA.

The number needed to respond to treatment was low; 2 in the blood flow restriction group and 4 in the high-intensity group. The odds ratios in the table hereunder reveal that compared to the control group, people were more likely to benefit from the blood flow resistance exercises than people who benefit from receiving advice only. The same is true for high-intensity resistance training, although here the 95% confidence interval reveals that this odds ratio is not significant.

Pain also improved with a clinically meaningful difference in both training groups, but not in the advice-only group. In the blood flow restriction group, pain improved to a greater extent (-2.3 vs -1.8). No clinically meaningful improvements were found with regard to grip strength. Both training groups improved by approximately 10%. An improvement of 20% has been suggested to be clinically relevant by previous studies.

Considering the questionnaires, only in the high-intensity resistance training group, a clinically relevant change in the Patient Specific Functional Scale (PSFS) was observed, with an average change of 2.8 points. No important differences were noted in the DASH and FIHOA questionnaires.

Questions and thoughts

“The FIHOA was chosen to calculate the number of responders because it was specifically created for hand OA.” However, findings indicate that there were no statistically significant findings and thus no clinically important changes in the FIHOA. Therefore, it remains unclear how the number of responders was calculated though.

This feasibility study showed improvements in grip strength that were significant but did not attain the threshold of 20% as suggested by earlier studies, to be seen as clinically relevant. However, this increase in grip strength of 10% may be promising, knowing that it was achieved in only 6 weeks in people around the age of 70 years. The demographics revealed that they have had pain for on average 5-10 years. Sure, this trial doesn’t give hard answers as it is only a feasibility study. However, it gives an important direction for future research and some of the principles may be useful for clinical practice. For example, you can motivate your patient with the information that even in this small trial and elderly population, after 6 weeks of resistance training for hand osteoarthritis, already a 10% increase in grip strength – which is important for many elderly in their daily life – can be expected. Along with this, you can indicate that even when pain exists for longer periods of time, this trial suggested that this does not influence the outcomes. Spreading these positive messages may help motivate your patient to engage in resistance training for hand osteoarthritis.

Talk nerdy to me

This feasibility study was reported according to the CONSORT guidelines and was pre-registered, as it should be. An intention-to-treat approach was used to analyze the results. Assessors were blinded to group allocation. Participants were stratified according to their baseline grip strength and this led to an equal average grip strength at baseline across groups.

Regarding resistance training, exercise prescriptions followed the recommendations from the American College of Sports Medicine. This study was the first to implement blood flow restriction training into the resistance training for osteoarthritis of the hand in symptomatic people, and it showed promising results which should be explored further.

A very promising aspect is that only 2 participants withdrew from the study, one for personal reasons and the other due to excessive pain. However, the results indicated that exercise-induced pain was almost non-existent and did not lead to pain flare-ups. So it appears that resistance training for osteoarthritis of the hand is feasible and does not necessarily lead to increases in pain.

Take home messages

What can we learn from these preliminary results? Awaiting the findings from the robust randomized controlled trial, this study teaches us that we do not need to fear resistance training for osteoarthritis of the hands as it does not lead to pain flare-ups and may help to reduce pain in elderly individuals. Grip strength did not improve to a clinically meaningful level, but resistance training for longer periods than 6 weeks may potentially be necessary and promising as this 6-week trial found improvements of 10% already. Blood flow restriction, and resistance training for osteoarthritis of the hand, which was studied for the first time in this population, seems promising and feasible.

Reference

Magni, N., McNair, P., & Rice, D. (2022). Six weeks of resistance training (plus advice) vs advice only in hand osteoarthritis: A single-blind, randomised, controlled feasibility trial. Musculoskeletal Science and Practice, 57, 102491.