"Investigation of the Effect of Radial Nerve Mobilization on Pain, Function and Grip Strength in Patients With Hand Thumb Osteoarthritis"
Phase: NA
Conditions: Osteoarthritis Thumb, Joint Diseases, Radial Neuropathy
Sponsor: Gazi University

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Document Date: 05/12/2023  
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Investigation of the Effect of Radial Nerve Mobilization on Pain, Function, and Grip 
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Strength in Patients with Thumb Osteoarthritis: A Randomized Controlled Trial 
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Ethics Approval: The study was conducted with the approval of the Ethics Review Board of 
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Gazi University, Ankara, Turkey. (approval number 2022 - 1117). 
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Clinical trials ID: NCT05650970 
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MATERIALS AND METHODS 
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The design of this prospective, randomized controlled, single-blinded parallel study was 
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approved by the Gazi University Ethics Committee (Date: 04.10.2022, Research Code No: 
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2022 - 1117). 
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This study was conducted with patients who applied to the Hand Surgery Outpatient Clinic of 
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X hospital between November 2022 and February 2023 and were referred to hand therapy 
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with the diagnosis of TMC OA in Ankara. The patients included in the study were divided 
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into two groups: mobilization and control groups according to the order in which they applied 
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to the clinic. 
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The treatment and evaluation of all patients were carried out by two different hand therapists 
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at X University Hand Rehabilitation Unit. The evaluations were made twice, before treatment 
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and after four weeks of the treatment. The patients in both groups received treatment 2 
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sessions per week for 4 weeks. All patients were called for a second evaluation on a separate 
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day after the completion of their treatment to avoid an acute effect of the treatment session on 
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the results.  
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Participants 
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The inclusion criteria of the participants were the diagnosis of OA in the TMC joint and the 
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presence of pain. It was planned to exclude patients who had a history of surgery (trigger 
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finger, carpal tunnel, Dupuytren’s contracture, tenosynovitis, etc.) in the last 6 months, using 
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a splint for thumb during the previous 3 months, and who had lack of cooperation, which 
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could be an obstacle to completing the questionnaires. In addition, patients who were found to 
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have any extra pathologies of the upper extremity (epicondylitis, neck hernia, nerve 
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compression, bone cyst, etc.) that could cause pain during the study period and who started to 
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use splinting, pain relieving treatments such as medications or injection were excluded from 
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the study. Evaluation and treatment of patients with bilateral involvement were done for both 
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hands and each hand’s results were recorded separately. Among the data of these patients, 
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clinical status (symptomatic hand, stage, and symptom duration), pain (at rest, activity, and 
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night), strength (gross grip, lateral, and double pinch), and performance in the Nine-Hole Peg 
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Test (9HPT) were included in the analysis for both hands separately; demographic 
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information (age, height, weight, gender) and scores of Michigan Hand Outcomes 
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Questionnaires (MHOQ) and Functional Index of Hand Osteoarthritis (FIHOA) were included 
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as single data for each patient.  
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The entire flow data of the patient enrollment is given in Figure 3 as a flowchart according to 
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the CONSORT guide. 
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The patients were informed about the study on the first day they came to the hand 
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rehabilitation unit for treatment, and their written consent was obtained. The patient's age, 
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gender, height, body weight, dominant and affected hand, surgical history, previous 
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treatments, disease stage, and duration of symptoms were recorded. Afterward, physical 
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assessments were performed.  
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Outcome measures 
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In this study, our primary outcome measure was the improvement in pain level; secondary 
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outcome measures were the improvement in thumb function and grip strength. 
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The pain level of the participants was evaluated with the Visual Analog Scale (VAS) in 3 
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different conditions including rest, activity, and night. The assessment was made with a 10-cm 
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straight line with endpoints describing the intensity of the pain. All patients were asked to mark 
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the pain level corresponding to the intensity of the pain on the line between “0” representing 
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“no pain” and “10” representing “the most/extremely unbearable pain”. The distance between 
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“0” and the mark made by the patients was measured and recorded in cm. 
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A hydraulic hand dynamometer (Jamar ®) was used for grip strength assessment, and a pinch 
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meter was used for bipod and lateral pinch strength. These measurements were made in the 
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standard sitting position as determined by the American Association of Hand Therapists. The 
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participant holds the elbow at 90 degrees flexion and the wrist in a neutral position at the side 
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of the trunk. During the assessment, the patient sits in a chair with a backrest. During the grip 
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strength measurements, the patient was asked to squeeze as hard as possible, and the 
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measurements were repeated three times consecutively for both hands. The mean value of the 
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measurement results was taken and recorded in kilograms (kg). 
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 9HPT was used in the evaluation of the functionality and fine dexterity level of each hand. 
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During this evaluation, the patient sits in a comfortable position. The patient was taught the 
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test to be performed and allowed to make a trial. Starting from the position where the pegs 
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were inserted into the holes, the patient was asked to remove all the pegs as fast as he/she 
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could with the evaluated hand, remove the last one, and then quickly insert the pegs into the 
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holes. The total removal and insertion times were recorded in seconds for both hands 
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separately. 
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 The FIHOA questionnaire developed specifically for hand osteoarthritis was used to assess 
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the level of disability. The questionnaire consists of 10 items containing statements about the 
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use of hands in daily life, and each item is scored from 0 to 3 points according to the difficulty 
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level: "0: possible without difficulty", "1: possible with slight difficulty", "2: possible with 
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importance difficulty", “3: impossible’’. The total score varies from 0 to 30 points. As a result 
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of this questionnaire, a low score represents a better function, while a high score represents a 
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worse function. The adapted version of the Turkish language was used. 
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The Michigan Hand Outcomes Questionnaires (MHOQ) were used in the functionality and 
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general evaluation of hand use bilaterally and right-left separately in daily life. The MHOQ is 
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reliable, valid, and responsive in patients with TMC joint osteoarthritis. The questionnaire 
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evaluates pain, function, aesthetic appearance, and satisfaction as sub-parameters. Since the 
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MHOQ measures function/satisfaction, the higher the score on the questionnaire, the higher 
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the reported functionality/satisfaction. The adapted version to the Turkish language was used. 
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Interventions 
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The study consisted of two groups: mobilization and control group. The only difference 
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between the mobilization group from the control group was the addition of radial nerve 
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mobilization exercises to the treatment program in this group. The remaining treatment 
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program was the same in both groups. Both groups in the study were included in the treatment 
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program twice per week for 4 weeks in the clinic. Patients were also instructed to repeat the 
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exercises and interventions at home 3 times per day. The treatment program for the patients 
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consists of the interventions below: 
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• Patient education: During the treatment period, patients were told not to use their hands for 
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heavy work and not to perform any application other than the treatment. Patients were 
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assessed about how much they use the hand during the day in daily life, during the recreation 
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and hobby times and they were educated about the correct grip positions as explained below. 
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• Teaching correct grip techniques: Patients were taught correct gripping techniques with 
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objects of different sizes and shapes and were informed about maintaining this position during 
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their daily activities (Figures 1 and 2). 
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• Massage: Massage was applied on the superficial branch of the radial nerve trace and the 
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thumb. Relaxation in the tissue, pain relief with mechanical stimulation, and edema reduction 
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were aimed. 
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• Nerve mobilization exercise: Radial nerve mobilization exercises were performed in two 
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consecutive ways: isolated wrist (ulnar-radial deviation with the thumb grasped in the palm in 
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a fist) and combined wrist-elbow (wrist in ulnar deviation with the elbow in extension and 
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wrist in radial deviation with the elbow in flexion, starting in anatomical posture). These 
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exercises were only given to the mobilization group. 
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• Ice therapy: It was applied on the dermatome of the superficial branch of the radial nerve for 
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10-12 minutes at the end of the treatment. 
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Data analysis 
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SPSS 26.0 program was used for statistical analysis of the data. The measured data were 
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expressed as percentages (%) and numbers (n) for qualitative variables and mean ± standard 
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deviations for quantitative variables. The Pearson Chi-Square test was used for the 
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comparison of the categorical variables (gender, dominant hand, affected hand, bilateral 
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involvement, and history of surgery for the disease). All participants with available baseline 
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data were included in the analyses. Missing outcomes were imputed based on baseline values. 
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No participant was excluded from the final analysis because of missing data.  The Mann-
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Whitney U test was used to compare the differences (delta) before and after the treatment. 
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The magnitude of effect sizes of differences between groups was calculated using Monte 
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Carlo defining clinically meaningful effect sizes with 95% Confidence level. P value <0.05 
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was accepted for statistical significance.  
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RESULTS 
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Sixty-four patients were invited to the study. A total of 6 patients were excluded because 2 of 
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these patients did not meet the inclusion criteria (concomitant bone cyst in one patient and 
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diagnosis of entrapment neuropathy in one patient) and 4 patients refused to participate in the 
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study. After exclusion, 58 patients were included in the study. At the end of the 4-week 
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treatment program, the data of 51 patients who completed the treatment program. Missing 
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data of the 7 patients who discontinued were also included in the analysis after multiply 
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imputation by maximum-likelihood-based regression methods. As a result, data from a total 
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of 58 patients were analyzed. The remaining 58 patients were included in the mobilization 
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(n=28) or control group (n=30). The patients did not know which group they belonged to. One 
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patient in the mobilization group was excluded after the start of the study as she received an 
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additional treatment. One another patient in this group discontinued the treatment program. 
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Five patients in the control group discontinued the treatment. All participants with available 
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baseline data were included in the analyses. Missing outcomes were imputed based on 
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baseline values. No participant was excluded from the final analysis because of missing data. 
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Finally, the data of 58 patients in total, 28 in the mobilization group and 30 in the control 
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group were compared. Since 3 patients in the mobilization group and 1 patient in the control 
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group had bilateral involvement, the evaluation and treatment of these patients were 
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performed separately for both hands. Therefore, the data from 58 patients (mobilization: 28, 
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control: 30) and 62 hands (mobilization: 31, control: 31 hands) were analyzed. (Figure 3). 
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Both groups were similar regarding their demographic and clinical characteristics (p>0.05). 
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The two groups differed only in the number of participants with a history of surgery for TMC 
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OA. The number of patients who had surgery in the control group was 6 (20%) and 1 (3.57%) 
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in the mobilization group (p=0.045) (Table 1). Moreover, both groups were at similar clinical 
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levels in terms of the results of the pre-treatment evaluations in all parameters (p>0.05) (Table 
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2). 
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Comparison of the differences between the two groups before and after the treatment showed 
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that the improvement in pain level in rest (p=0.002), in activity (p=0.008), at night (p=0.053); 
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and gross grip (p=0.013) and lateral pinch strength (p=0.003); FIHOA score (p=0.001); and 
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MHOQ overall score (p=0.005) in the mobilization group were significantly superior to the 
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control group (Table 3).  
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Figure 1: Gripping position before patient education 
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Figure 2: Gripping position after patient education 
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166 
 
167 
 
168 
 
169 
 
170 
 
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Figure 3: CONSORT flow-diagram of participants throughout the study period  
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177 
 
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Tablo 1: Baseline characteristics of the study groups  
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Assessed for eligibility (n=64)  
Excluded (n=6) 
  did not match inclusion criteria (n=2, 
one had a bone cyst, and the other 
had nerve compression)  
  declined to participate (n=4) 
Included in the main analyses (n=28 patients 
with 31 hands 
n=26 patients (29 hands) 
-Discontinued treatment (n=1) 
-Exclusion criteria (got injection) (n=1) 
Allocated to mobilization group (n=28 patients 
with 31 hands) 
*Three patients were bilaterally symptomatic 
n=25 patients (26 hands) 
-Discontinued treatment (n=5) 
Allocated to control group (n=30 patients with 
31 hands) 
*One patient was bilaterally symptomatic 
Included in the main analyses (n=30 patients 
with 31 hands) 
Allocation 
Analyses  
Follow-Up 
Randomized (n=58) 
Enrollment 
Note: All participants with available 
baseline data were included in the 
analyses. Missing outcomes were 
imputed on the basis of baseline 
values. No participant was excluded 
because of missing outcume values. 

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Baseline characteristics 
Mobilization 
group (n=28) 
Control group 
(n=30) 
P-
value 
Z-
value 
Effect size 
[CI] 
Age (years) (Mean ± SD) 
57.50 ± 11.30  
61.67 ± 9.82 
0.249 
-1.153 
0.45 
[0.44;0.46] 
Height (cm) 
161.21 ± 9.41  
160.83 ± 8.26  
0.956 
-0.055 
1 [1] 
Body weight (kg) 
73.64 ± 12.94  
74.90 ± 8.14 
0.586 
-0.545 
0.40 
[0.39;0.41] 
Gender (n) (%) 
(female/male)  
22/6 (78.5%) 
25/5 (83%) 
0.644 
 
 
Surgical history (n) (%) 
(operated/nonoperated) 
1/27 (3.57%) 
6/24 (20%) 
0.045* 
 
 
Symptom duration 
(months) 
15.46 ± 13  
15.93 ± 13.99 
0.994 
-0.008 
0.62 
[0.61;063] 
Dominant side (n) (%)       
Right     
Left 
 
26 (92.85%) 
2 (7.15%) 
 
29 (96.66%) 
1 (3.34%) 
0.513 
 
 
Symptomatic side (n) (%) 
Right 
Left 
Bilateral 
 
14 (50%) 
11 (39.28%) 
3 (10.72%) 
 
12 (40%) 
17 (56.66%) 
1 (3.34%) 
0.305 
 
 
Dominant hand 
symptomatic (n) (%)              
Yes 
No     
Bilateral 
 
16 (57.14%) 
9 (32.14%) 
3 (10.72%) 
 
13 (43.33%) 
16 (53.33%) 
1 (3.34%) 
0.201 
 
 

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Grade (Eaton-Littler 
classification) (n) (%)             
Grade 1 
Grade 2    
Grade 3 
Grade 4 
 
1 (3.57%) 
8 (28.57%) 
17 (60.72%) 
2 (7.14%) 
 
3 (10%) 
14 (46.66%) 
12 (40%) 
1 (3.34%) 
0.288 
 
 
 
192 
n: Number of participants, SD: Standart Deviation, *p<0.05: statistically significant, CI: 
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Confidence Interval 
194 
 
195 
 
196 
 
197 
 
198 
 
199 
 
200 
 
201 
 
202 
 
203 
 
204 
 
205 
 
206 
 
207 
 
208 
 
209 
 
210 
 
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Table 2: Baseline values and between-group comparison results 
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Baseline Values 
Mobilization 
group (n=31) 
(Mean ± SD) 
Control group 
(n=31) 
(Mean ± SD) 
P value 
Z value 
 
Effect size 
[CI] 
Pain in Resting (cm)  
3.34 ± 2.33  
2.93 ± 2.61  
0.373 
-0.891 
0.37 
[0.36;0.38] 

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SD: Standart Deviation, MHOQ: Michigan Hand Outcomes Questionnaires, FIHOA: 
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Functional Index of Hand Osteoarthritis, 9HPT: 9 Holes Peg Test, *p<0.05: statistically 
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significant, CI: Confidence Interval 
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221 
 
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Tablo 3: Result of comparing the differences between the pre- and post-treatment outcome 
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measures between the groups 
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Pain in Activity (cm) 
7.07 ± 2.14  
6.70 ± 1.85 
0.597 
-0.529 
0.59 
[0.58;0.60] 
Pain in Night (cm) 
2.88 ± 2.83  
2.74 ± 3.23  
0.405 
-0.833 
0.41 
[0.40;0.41] 
Grip Strength (kg) 
18.90 ± 9.05  
19.85 ± 7.52  
0.517 
-0.648 
0.51 
[0.51;0.53] 
Bipod Pinch Strength 
(kg) 
3.16 ± 1.29  
3.02 ± 1.35  
0.582 
-0.550 
0.58 
[0.57;059] 
Lateral Pinch Strength 
(kg) 
5.29 ± 2.04  
5.40 ± 1.86  
0.622 
-0.493 
0.62 
[0.61;0.63] 
9HPT Time (second) 
23.62 ± 4.15  
24.33 ± 5.29 
0.598 
-0.528 
0.61 
[0.60;0.62] 
FIHOA Score  
13.39 ± 6.06  
10.61 ± 6.45   
0.057 
-1.906 
0.055 
[0.050;0.059] 
MHOQ Overall Score 
49.37 ± 13.20  
53.04 ± 10.40  
0.145 
-1.457 
0.14 
[0.14;015] 

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Outcome measures 
Differences 
between 
Pre 
and 
post-
treatment 
in 
mobilization 
group 
(Mean ± SD) 
Differences 
between 
Pre 
and 
post-
treatment 
in 
control group 
(Mean ± SD) 
P value 
Z 
value 
Effect 
size 
[CI] 
Pain (cm)                          
Resting 
Activity 
Night 
 
1.89 ± 2.10 
3.26 ± 2.34  
2.19 ± 2.43 
 
-0.02 ± 2.43 
1.64 ± 1.87 
0.90 ± 1.44 
 
0.002* 
0.008* 
0.053* 
 
 
-3.055 
 
-2.657 
-1.935 
0.002 
[0.001;0.002] 
 
0.009 
[0.007;0.011] 
 
0.055 
[0.051;0.059] 
Gross Grip Strength 
(kg) 
4.31 ± 3.01 
1.86 ± 4.68 
0.013* 
-2.487 
0.009 
[0.007;0.01] 
Bipod Pinch Strength 
(kg) 
0.68 ± 0.92 
0.22 ± 1.33 
0.074 
-1.786 
0.073 
[0.068;0.078] 
Lateral Pinch Strength 
(kg) 
1.29 ± 1.65 
0.05 ± 1.16 
0.003* 
-2.954 
0.002 
[0.001;0.002] 
9HPT Time (second) 
2.52 ± 3.35  
1.48 ± 3.02 
0.192 
-1.303 
0.198 
[0.19;0.020] 
FIHOA Score  
5.54 ± 4.03 
2.06 ± 4.20 
0.001* 
-3.237 
0.001 
[0.001;0.002] 
MHOQ Overall Score 
13.62 ± 9.49 
5.91 ± 11.05 
0.005* 
-2.811 
0.005 
[0.003;0.006] 
 
225 
n: Number of participants, SD: Standart Deviation, MHOQ: Michigan Hand Outcomes 
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Questionnaires, FIHOA: Functional Index of Hand Osteoarthritis, 9HPT: 9 Holes Peg Test, 
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*p<0.05 statistically significant, CI: Confidence Interval 
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