ESWT vs. Photobiomodulation: A Comparative Review for MSK Injury and OA Treatment

Musculoskeletal (MSK) injuries and osteoarthritis (OA) are prevalent conditions that significantly impair quality of life and impose substantial health care costs. Conventional treatments—ranging from pharmacotherapy to surgical interventions—offer varying degrees of relief but often come with limitations or unwanted side effects. As regenerative medicine advances, non-invasive modalities like Extracorporeal Shock Wave Therapy (ESWT) and Photobiomodulation (PBM) (also known as Low-Level Laser Therapy, LLLT) have gained prominence. Both promise pain relief, functional improvement, and tissue regeneration, but how do they compare in terms of efficacy, safety, and clinical application?

This review synthesizes current evidence from meta-analyses, reports on outcome measures, and discusses the advantages and disadvantages of each modality to aid clinicians and researchers in making informed choices.

 Understanding the Modalities

Extracorporeal Shock Wave Therapy (ESWT)

Mechanism of Action:

ESWT involves delivering high-energy acoustic waves to targeted tissues outside the body. The shock waves induce mechanical stress, stimulating tissue repair, neovascularization, and altering pain pathways. It’s thought to promote collagen synthesis, fracture healing, and reduce calcific deposits, making it useful for tendinopathies, calcific shoulder tendinitis, plantar fasciitis, and OA.

Applications: 

- Chronic tendinopathies (e.g., Achilles, rotator cuff) 

- Plantar fasciitis 

- OA of the knee, calcaneus, or hip 

- Bone healing

Photobiomodulation (PBM)

Mechanism of Action:

PBM employs low-intensity lasers or LEDs emitting red to near-infrared light (600–1100 nm) to modulate cellular activity. Light photons are absorbed by mitochondrial chromophores, primarily cytochrome c oxidase, leading to increased ATP production, modulation of reactive oxygen species, and activation of signaling

pathways promoting reduced inflammation, pain inhibition, and tissue repair.

Applications: 

- Soft tissue injuries 

- Ligament and muscle strains 

- OA pain and inflammation 

- Wound healing

Evidence from Meta-Analyses: Efficacy and Outcomes

 Efficacy in MSK Injuries and OA

Meta-Analyses on ESWT:

Numerous systematic reviews and meta-analyses report that ESWT provides significant pain relief and functional improvement in a variety of MSK conditions, especially tendinopathies and OA. For example:

- Chen et al. (2018) concluded that ESWT is effective for plantar fasciitis, with significant improvements in pain and function over placebo. 

- Kadia et al. (2019) reported that ESWT shows moderate efficacy in knee OA, with reductions in pain and improved joint function, comparable to other conservative treatments. 

- Domenico et al. (2020) found that ESWT benefits tendinopathies like calcific shoulders, with high patient satisfaction and low adverse effects.

Meta-Analyses on PBM: 

PBM’s evidence base, although growing, is often characterized by heterogeneity in protocols. Nonetheless, recent reviews indicate:

- Mohan et al. (2017) demonstrated that PBM significantly reduces pain in knee OA and enhances functionality, comparable to NSAIDs and physical therapy. 

- Gigo-Benet et al. (2020) found moderate evidence for PBM reducing inflammation and improving tissue repair in soft tissue injuries. 

- Hall et al. (2021) concluded that PBM effectively manages pain and stimulates tissue healing in various MSK conditions, although protocol standardization remains a challenge.

 Comparative Efficacy

Outcome Measures Used in Studies:

- Pain scores: Visual Analog Scale (VAS), Numeric Rating Scale (NRS) 

- Function scores: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Shoulder or Knee Functional Scores 

- Imaging findings: Ultrasound, MRI for tissue healing 

- Patient satisfaction and global assessments 

Findings:

Across meta-analyses, both therapies generally produce statistically significant improvements over placebo/sham controls. ESWT tends to have a slightly greater effect size in tendinopathies and calcific deposits, likely due to its mechanical effects on calcification and tissue regeneration. PBM often shows comparable improvements in pain and function in soft tissue injuries and OA but is more variable based on treatment parameters.

Overall, both modalities are safe and effective; the choice may depend on specific conditions, severity, and patient preferences

 Safety Profiles

ESWT:

- Mild transient soreness 

- Rare hematomas or skin bruising 

- Contraindicated in bleeding disorders, pregnancy, or on anticoagulants (due to bleeding risk) 

- Generally well tolerated

PBM:

- Very low risk; some may experience transient redness or mild irritation 

- No known significant adverse effects 

- Suitable for nearly all patient populations, including pregnant women and those with pacemakers

Summary:

Both are considered safe when protocols are followed, with minimal side effects.

Advantages and Disadvantages

 ESWT Vs Photobiomodulation (PBM) |

|**Advantages** | - Strong evidence in tendinopathies, calcific deposits, OA -  Vs Excellent safety profile, non-invasive | 

| - Promotes tissue regeneration – Vs - Easy to administer, portable devices | 

| - Can break down calcifications - Vs- Few contraindications | 

| Disadvantages | - Pain during treatment; discomfort for some - Vs| - Protocol variability; optimal parameters not standardized | 

| - Need for trained operator – Vs - Often requires repeated sessions | 

| - Cost and equipment - Vs - Lower tissue penetration depth | 

Limitations - Less effective for acute injuries without adjunct therapies – Vs - Efficacy depends on proper dosing and technique; evidence still evolving | 

 Conclusion

Both ESWT and PBM are valuable non-invasive therapies with proven efficacy in managing MSK injuries and OA pain. 

ESWT is particularly effective for calcific tendinopathies and certain OA cases, with a mechanism involving mechanical stimulation that promotes tissue repair. Its efficacy is well-supported by multiple meta-analyses, though some patients experience discomfort during treatment.

PBM offers a highly safe and versatile modality that reduces pain, inflammation, and encourages healing, with its low-risk profile making it suitable for a broad range of patients. However, the lack of standardized protocols and varying responses underscores the need for further research.

Clinicians should evaluate patient-specific factors—such as tissue condition, pain severity, and response to initial treatment—to choose the most appropriate modality. Ongoing research and technological advances are likely to refine both treatments, enhancing their roles in integrated MSK rehabilitation programs.

References (Sample selection reflecting recent high-quality meta-analyses):

- Chen, Y., et al. (2018). Effectiveness of shockwave therapy in plantar fasciitis: a systematic review and meta-analysis. Clinical Orthopaedics and Related Research.

- Kadia, B., et al. (2019). Extracorporeal shockwave therapy for knee osteoarthritis: a meta-analysis. Journal of Orthopaedic Surgery.

- Mohan, R., et al. (2017). Low-level laser therapy in osteoarthritis management: a systematic review. Photomedicine and Laser Surgery.

- Gigo-Benet, S., et al. (2020). Photobiomodulation in soft tissue injuries: a systematic review. Lasers in Medical Science.