Effects of Aerobic and Combined Exercise on Pain and Fatigue in Workers With Chronic Neck Pain

This randomized controlled trial investigated the acute effects of aerobic exercise and combined aerobic and cervical-upper extremity resistance exercise on pain sensitivity, pain perception, and fatigue in workers with chronic non-specific neck pain exposed to high ergonomic risk.

Participants were recruited from occupational groups with high ergonomic risk and were assessed in two sessions. The first session was conducted in the workplace and included eligibility screening, demographic data collection, and ergonomic risk assessment. Participants were then randomly assigned to aerobic exercise, combined exercise, or control groups.

The second session was conducted in a university laboratory setting. Baseline assessments were performed, followed by the intervention. Outcome measures were collected before the intervention (T0), immediately after (T1), and 20 minutes after the intervention (T2).

The aerobic exercise group performed moderate-intensity cycling using a recumbent ergometer (64-76% of maximum heart rate), consisting of a 5-minute warm-up, 30 minutes of exercise, and a 5-minute cool-down. The combined exercise group performed aerobic exercise at the same intensity, followed by cervical and upper-extremity resistance exercises focusing on motor control and scapular stabilization. This protocol included a 5-minute warm-up, 15 minutes of aerobic exercise, 15 minutes of resistance exercise, and a 5-minute cool-down. The control group received a 30-minute educational session on exercise and workplace ergonomics.

Pain sensitivity was assessed using pressure pain threshold measurements obtained with a digital algometer at the C2, C5, and upper trapezius regions. Neck pain, overall body pain perception, and fatigue were evaluated using numerical rating scales (0-10).

Sample size was calculated using G*Power (v3.1.9.6) based on a previous study (effect size = 0.165 for a three-group design), with an alpha level of 0.05 and power of 0.80, resulting in a required sample of 78 participants. Considering a 20% drop-out rate, 95 participants were targeted.

Statistical analyses were performed using SPSS. Data normality was assessed using the Shapiro-Wilk test. Baseline differences between groups were analyzed using ANOVA and chi-squared tests. The primary analysis evaluated group × time interactions using repeated-measures ANOVA (T0, T1, T2), with Bonferroni post-hoc tests applied when appropriate. Statistical significance was set at p < 0.05.

The study focused on exercise-induced hypoalgesia (EIH) and aimed to compare the immediate and short-term responses to different exercise modalities in a working population with chronic neck pain.

Inclusion criteria

• Aged 20-65 years
• Diagnosed with chronic non-specific neck pain within the past year
• Neck pain intensity ≥4 on a numerical rating scale for at least 3 months
• Actively employed for at least 1 year in similar occupational conditions
• High ergonomic risk (Rapid Upper Limb Assessment - RULA score ≥3)

Exclusion criteria

• Neurological, cardiopulmonary, or rheumatological disorders
• History of cervical surgery or traumatic injury
• Specific cervical or lumbar pathology
• Whiplash injury, or any traumatic musculoskeletal injury
• Recent physical therapy or regular exercise in the past six months
• Neck pain unresponsive to conservative treatment
• Diagnosed thoracic outlet syndrome, rotator cuff pathology, vertebrobasilar insufficiency, or frozen shoulder
• Pregnancy
• Use of antidepressant medication
• Positive clinical tests (Spurling, cervical distraction, Valsalva, radial, ulnar, and median nerve tension tests)