Whole-Body Vibration in Patients With Patellofemoral Pain Syndrome

Official title

Efficacy of Whole-Body Vibration in Patients With Patellofemoral Pain Syndrome: A Prospective, Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Overview

Patellofemoral Pain Syndrome (PFPS), or anterior knee pain, is one of the most common disorders affecting the lower extremities. Currently, there is no established "gold standard" treatment for PFPS. However, various interventions-including strengthening of the hip and knee muscles (e.g., hip abductors, external rotators, and knee extensors), taping, bracing, foot orthoses, manual therapy, acupuncture, blood flow restriction training, and conventional physical agents (e.g., ultrasound, cryotherapy, neuromuscular electrical stimulation, laser therapy, electromyographic biofeedback, etc.)-have been reported to provide meaningful clinical benefits. Strengthening of the hip and knee muscles alone has been shown to improve both pain and function in the short, medium, and long term. In recent high-quality studies, hip and knee muscle strengthening has been recognized as an effective "classical" treatment approach for PFPS. Regarding the mechanism of pain relief, previous research suggests that strengthening these muscles may alleviate pain by stabilizing patellar motion and/or reducing pressure on the patellofemoral joint. Similar to traditional resistance training, whole-body vibration (WBV) training is an alternative method for muscle strengthening. WBV platforms can generate vertical vibrations that stimulate tonic vibration reflexes through muscle spindles, thereby activating homonymous alpha motor neurons and inducing reflex muscle contractions. As a result, increased motor unit recruitment enhances the excitability of muscle spindles, leading to improved muscle strength. Additionally, WBV training can improve muscle balance, strength, and function. Therefore, combining WBV with hip and knee strengthening exercises may represent a more effective treatment strategy for PFPS. The aim of this study is to evaluate whether the combination of WBV and hip-knee muscle strengthening is more effective in reducing pain and improving function than hip-knee strengthening alone.

Detailed description

Patellofemoral Pain Syndrome (PFPS), or anterior knee pain, is one of the most common disorders affecting the lower extremities.

Currently, there is no established "gold standard" treatment for PFPS. However, various interventions-including strengthening of the hip and knee muscles (e.g., hip abductors, external rotators, and knee extensors), taping, bracing, foot orthoses, manual therapy, acupuncture, blood flow restriction training, and conventional physical agents (e.g., ultrasound, cryotherapy, neuromuscular electrical stimulation, laser therapy, electromyographic biofeedback, etc.)-have been reported to provide meaningful clinical benefits. Strengthening of the hip and knee muscles alone has been shown to improve both pain and function in the short, medium, and long term. In recent high-quality studies, hip and knee muscle strengthening has been recognized as an effective "classical" treatment approach for PFPS. Regarding the mechanism of pain relief, previous research suggests that strengthening these muscles may alleviate pain by stabilizing patellar motion and/or reducing pressure on the patellofemoral joint.

Similar to traditional resistance training, whole-body vibration (WBV) training is an alternative method for muscle strengthening. WBV platforms can generate vertical vibrations that stimulate tonic vibration reflexes through muscle spindles, thereby activating homonymous alpha motor neurons and inducing reflex muscle contractions. As a result, increased motor unit recruitment enhances the excitability of muscle spindles, leading to improved muscle strength. Additionally, WBV training can improve muscle balance, strength, and function. Therefore, combining WBV with hip and knee strengthening exercises may represent a more effective treatment strategy for PFPS. The aim of this study is to evaluate whether the combination of WBV and hip-knee muscle strengthening is more effective in reducing pain and improving function than hip-knee strengthening alone.

Interventions

• Device Whole body vibration
  In this group, prior to the patient stepping onto the platform, the practitioner will turn off the vibration motor of the device and activate an external motor (which is not in contact with the WBV device, has no effective vibration capability, and only produces sound), installed by our team. Since the visual display of the device remains active, patients will not be aware that the actual vibration function is disabled, thereby preventing any bias related to device inactivity.
• Device Sham Whole Body Vibration
  In this group, prior to the patient stepping onto the platform, the practitioner will turn off the vibration motor of the device and activate an external motor (which is not in contact with the WBV device, has no effective vibration capability, and only produces sound), installed by our team. Since the visual display of the device remains active, patients will not be aware that the actual vibration function is disabled, thereby preventing any bias related to device inactivity.

Primary outcome measures

• VAS [Time frame: Change from baseline VAS at the 8th week after the treatment]

Secondary outcome measures (9)

• Anterior Knee Pain Scale [Time frame: Change from baseline AKPS score at the 8th week after the treatment]
• Short Form - 36 [Time frame: Change from baseline SF-36 score at the 8th week after the treatment]
• Muscle Mass Assessment via Ultrasound [Time frame: Change from baseline muscle mass assessment at the 8th week after the treatment]
• Change in peak torque at 60°/s (Nm) of the knee muscles measured by isokinetic dynamometer [Time frame: Change from baseline to Week 8 after treatment]
• Change in peak torque at 240°/s (Nm) of the knee muscles measured by isokinetic dynamometer [Time frame: Change from baseline to Week 8 after treatment]
• Assessment of the hamstring/quadriceps ratio at 60°/s with an isokinetic dynamometer [Time frame: Change from baseline VAS at the 8th week after the treatment]
• Assessment of the hamstring/quadriceps ratio at 240°/s with an isokinetic dynamometer [Time frame: Change from baseline to week 8 after treatment]
• Change in Total Work (J) of the Knee Muscles at 60°/s With an Isokinetic Dynamometer [Time frame: Change from baseline to Week 8 after treatment]
• Change in Total Work (J) of the Knee Muscles at 240°/s With an Isokinetic Dynamometer [Time frame: Change from baseline to Week 8 after treatment]

Eligibility criteria

Inclusion criteria

• Aged between 18 and 40 years,
• Diagnosed with unilateral Patellofemoral Pain Syndrome (PFPS),
• Reporting anterior knee pain or pain behind the patella in at least two of the following activities:

ascending stairs, jumping, running, squatting, kneeling, prolonged sitting,

\- Positive results in at least two of the following clinical tests: Eccentric step-down test, Patellar border tenderness test, Patellar grind (Clarke's) or apprehension test,

• Ability to understand the procedures, potential benefits, and possible adverse effects,
• Willingness to participate in the treatment program.

Exclusion criteria

• Severe injury or pathological changes in knee structures (e.g., ligaments, menisci, patellar tendons, iliotibial bands, joint capsules, or plicae),
• History of significant trauma or surgery involving the knee or lower extremity,
• History of patellar dislocation or subluxation,
• Diagnosis of Osgood-Schlatter disease or Sinding-Larsen-Johansson syndrome,
• Joint effusion in the knee, or presence of redness, swelling, or increased warmth on physical examination,
• Serious systemic conditions, including cardiovascular diseases, tumors, gallstones or kidney stones, severe disc or spinal lesions, pacemaker implantation, epilepsy, recent fractures or surgeries, or acute arthritis,
• Pregnancy.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 1 center

• Pamukkale University — Denizli

Publications

• Dag F, Dal U, Altinkaya Z, Erdogan AT, Ozdemir E, Yildirim DD, Colak M. Alterations in energy consumption and plantar pressure distribution during walking in young adults with patellofemoral pain syndrome. Acta Orthop Traumatol Turc. 2019 Jan;53(1):50-55. doi: 10.1016/j.aott.2018.10.006. Epub 2018 Oct 25. PMID 30482589
• Corum M, Basoglu C, Yakal S, Sahinkaya T, Aksoy C. Effects of whole body vibration training on isokinetic muscular performance, pain, function, and quality of life in female patients with patellofemoral pain: a randomized controlled trial. J Musculoskelet Neuronal Interact. 2018 Dec 1;18(4):473-484. PMID 30511951
• Dieterich AV, Pickard CM, Strauss GR, Deshon LE, Gibson W, McKay J. Muscle thickness measurements to estimate gluteus medius and minimus activity levels. Man Ther. 2014 Oct;19(5):453-60. doi: 10.1016/j.math.2014.04.014. Epub 2014 May 10. PMID 24880207
• Dogan A, Sengul I, Askin A, Tosun A. Effect of static knee joint flexion on vastus medialis obliquus fiber angle in patellofemoral pain syndrome: An ultrasonographic study. PM R. 2022 Jul;14(7):802-810. doi: 10.1002/pmrj.12655. Epub 2021 Jul 23. PMID 34165244
• Kuru T, Dereli EE, Yaliman A. Validity of the Turkish version of the Kujala patellofemoral score in patellofemoral pain syndrome. Acta Orthop Traumatol Turc. 2010;44(2):152-6. doi: 10.3944/AOTT.2010.2252. PMID 20676018
• Kujala UM, Jaakkola LH, Koskinen SK, Taimela S, Hurme M, Nelimarkka O. Scoring of patellofemoral disorders. Arthroscopy. 1993;9(2):159-63. doi: 10.1016/s0749-8063(05)80366-4. PMID 8461073
• Takanashi Y, Chinen Y, Hatakeyama S. Whole-body vibration training improves the balance ability and leg strength of athletic throwers. J Sports Med Phys Fitness. 2019 Jul;59(7):1110-1118. doi: 10.23736/S0022-4707.18.09012-6. Epub 2018 Oct 10. PMID 30317837
• Alam MM, Khan AA, Farooq M. Effect of whole-body vibration on neuromuscular performance: A literature review. Work. 2018;59(4):571-583. doi: 10.3233/WOR-182699. PMID 29733043

Identifiers

NCT: NCT07382037 · PamukkaleU.ftr-HAlkan-001

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗