Comparisonofextracorporealshockwavetherapyandmanualtherapyonactivetriggerpointsofthesternocleidomastoidmuscleincervicogenicheadache:Arandomizedcontrolledtrial

Cervicogenic headache (CEH) is a debilitating condition characterized by unilateral head pain triggered by neck movement and sustained awkward postures, affecting about 4.1% of the general population and accounting for 15 to 20% of all headache patients. Myofascial trigger points (MTPs) in the sternocleidomastoid muscle (SCM) are increasingly recognized as a key contributor to this condition, potentially explaining about half of chronic pain in the head and neck region. While manual therapy (MT) has moderate evidence supporting its use for immediate pain relief in myofascial pain syndrome, it carries risks of adverse events and its efficacy depends heavily on therapist skill. Extracorporeal shock wave therapy (ESWT) has emerged as a noninvasive alternative for treating MTP-related pain, with demonstrated effectiveness in trapezius muscle myofascial pain syndrome.

However, no prior study had evaluated ESWT specifically for active trigger points in the SCM among CEH patients, leaving clinicians uncertain whether this approach could serve as a viable alternative to hands-on manual techniques.

Researchers at Weifang People's Hospital in China conducted a randomized controlled trial comparing ESWT versus MT for CEH patients with active trigger points in the SCM. Between March and December 2022, they recruited 42 patients (27 females, 15 males; mean age 33.2 years, range 18 to 45) who had experienced unilateral headache for at least three months and had not received any treatment during the prior three months. Patients were randomly allocated using sealed envelopes to either the ESWT group (n=21) or the MT group (n=21). The ESWT group received 1,000 shock waves with an energy flux density of 0.18 mJ/mm2 and frequency of 3.5 Hz using an American DJO 2074 device, applied once weekly for four weeks.

The MT group received manual trigger point compression and passive stretching, also once weekly for four weeks. All treatments were performed by designated physiotherapists with eight years of experience, while outcome assessors and the statistician remained blinded to group allocation. Measurements were taken at baseline, immediately postintervention (one day after the final treatment), and at four-week follow-up.

One patient in the ESWT group was lost to follow-up due to moving; missing data were imputed for intention-to-treat analysis. Both groups showed significant improvements across all outcome measures. Visual Analog Scale (VAS) scores decreased from 6.90±1.04 to 3.29±1.15 postintervention in the MT group and from 6.81±1.44 to 2.95±1.02 in the ESWT group, with effects maintained at four-week follow-up (p<0.01 for both groups). Pressure pain threshold increased significantly in both groups (MT: 18.03±3.29 to 25.28±3.06 N; ESWT: 17.83±3.76 to 26.48±3.58 N; p<0.01).

Neck Disability Index scores dropped from 28.52±5.11 to 16.24±3.05 in the MT group and from 26.76±4.17 to 15.48±3.80 in the ESWT group (p<0.01). Shear elastic modulus of the SCM decreased from 52.95±9.43 to 31.84±6.31 kPa in the MT group and from 54.37±8.58 to 29.87±6.82 kPa in the ESWT group (p<0.01). Repeated measures ANOVA revealed significant time effects for all outcomes (p<0.001), with large effect sizes for time (η²p=0.837 for VAS, 0.652 for PPT, 0.779 for NDI, 0.876 for stiffness). Crucially, there were no significant differences between groups at any time point for any outcome measure, and no significant time-by-group interactions.

This study provides important evidence that ESWT and MT are equally effective for treating active trigger points in the SCM among CEH patients, with both producing substantial and sustained improvements in pain, function, pressure pain threshold, and muscle stiffness. For clinicians, this means ESWT can serve as a legitimate alternative when manual therapy is contraindicated, unavailable, or when treating deeper muscles where manual techniques are difficult to apply. The noninvasive nature of ESWT, combined with its independence from therapist skill variability, makes it particularly attractive for standardizing care. For patients, both treatment options offer meaningful relief that persists for at least four weeks after treatment completion.

The study also validates shear wave elastography as a useful tool for objectively measuring muscle stiffness changes in response to treatment. However, the small sample size, lack of long-term follow-up beyond four weeks, and absence of a placebo or no-treatment control group mean that larger, longer studies are needed to confirm these findings and establish optimal ESWT parameters for this specific application.