Plantar Fasciitis, Chronic
Conditions
Keywords
plantar fasciitis, strengthening, stretching, proprioception, chronic plantar fasciitis
Brief summary
Plantar fasciitis is a common cause of heel pain, and although stretching exercises are a standard first-line treatment, current evidence on adding proprioception or knee-strengthening exercises remains limited. This study investigates whether adding knee strengthening or proprioception exercises to a standard stretching program improves pain, function, and disability in patients with chronic plantar fasciitis, and whether these interventions produce measurable changes in the biomechanical and kinesiological properties of the foot, ankle, and knee.
Detailed description
Plantar fasciitis is a degenerative condition of the plantar fascia and one of the most common musculoskeletal disorders affecting the foot, with an estimated prevalence of approximately 10% in the general population. It is diagnosed clinically based on history and physical examination, typically presenting as sharp heel pain during the first steps in the morning or after rest, tenderness on palpation of the medial calcaneal tuberosity, and a positive Windlass test. Risk factors include reduced ankle and first metatarsophalangeal joint range of motion, obesity, prolonged weight-bearing, and inappropriate footwear. Stretching of the plantar fascia and gastrocnemius-soleus complex is a well-established, evidence-based treatment for plantar fasciitis. However, the underlying mechanism of the condition cannot be fully explained by tissue shortening and mechanical loading alone; impaired neuromuscular control and balance also appear to play a contributory role. Prior research has found that adding hip- and ankle-directed strengthening exercises to a stretching program provides no additional benefit over stretching alone in patients with plantar fasciitis, while other studies have reported reduced hamstring and quadriceps muscle strength in this population. Individuals with plantar fasciitis have also been shown to exhibit impaired postural balance and an increased risk of falls. While proprioception exercises have demonstrated benefit in the rehabilitation of ankle injuries, their effectiveness has not yet been established in plantar fasciitis. Given these gaps, this study aims to evaluate whether knee-strengthening and proprioception exercises, when added to a standard stretching program, provide additional benefit in reducing pain and disability and improving the biomechanical and kinesiological properties of the foot, ankle, and knee in patients with plantar fasciitis.
Interventions
OTHERStretching
Participants will perform standardized plantar fascia and gastrocnemius-soleus stretching exercises. The protocol consists of stretching twice daily, 7 days per week, for 6 weeks.
OTHERProprioception and Stretching Exercises
In addition to the standard stretching protocol, participants in this group will perform a supervised, 6-week progressive proprioception exercise program administered by a physiotherapist three times per week. Exercises will be performed under both eyes-open and eyes-closed conditions on progressively less stable surfaces with task difficulty advanced on a weekly basis.
OTHERKnee Strengthening and Stretching Exercises
In addition to the standard stretching protocol, participants in this group will perform a supervised, 6-week progressive knee-strengthening program administered by a physiotherapist three times per week.
Sponsors
Karamanoğlu Mehmetbey University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Age between 18 and 65 years. * Formal diagnosis of plantar fasciitis, characterized by sharp pain during the first steps in the morning, pain that increases with prolonged activity, localized tenderness on palpation of the medial calcaneal tubercle or proximal fascia, and a positive Windlass test. * Symptom duration of at least 3 months. * Heel pain intensity score of Visual Analog Scale (VAS) \> 3. * Voluntary agreement to participate, evidenced by signing the written informed consent form.
Exclusion criteria
* History of acute lower-extremity trauma. * History of prior foot or ankle surgery. * Corticosteroid injection to the affected heel within the preceding 6 months. * Presence of systemic inflammatory or rheumatologic disease. * Uncontrolled systemic disease (e.g., uncontrolled hypertension, uncontrolled diabetes mellitus). * Current or past history of malignancy. * Current pregnancy. * Body mass index (BMI) ≥ 30 kg/m². * Any musculoskeletal, neuromuscular, ocular, or vestibular disorder that could impair balance or limit the ability to stand unsupported. * Neurocognitive or psychiatric conditions precluding adherence to the exercise protocols or outcome assessments.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pain Intensity (First-Step Morning, Evening, and Overall Daily Pain) | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | Pain intensity during the first steps in the morning, before going to bed, and overall daily pain will be assessed using the Visual Analog Scale (VAS). The scale consists of a 10-cm horizontal line ranging from 0 (no pain) to 10 (worst imaginable pain), on which participants mark the point corresponding to their perceived pain level. |
| Pressure Pain Threshold (PPT) | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | PPT will be assessed using a Baseline® 12-1442 dolorimeter (22-lb sensitivity range; Fabrication Enterprises Inc., USA) to evaluate deep-tissue mechanical sensitivity. With the participant positioned prone and the feet hanging off the table, gradually increasing pressure will be applied to the midpoint of the plantar fascia insertion at the calcaneus. The pressure at which the participant first perceives pain will be recorded. Three measurements will be taken at 30-second intervals, and the mean value will be used for analysis. |
| Foot Function and Health Status (Revised Foot Function Index, FFI-R) | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | The FFI-R is a self-reported, multidimensional questionnaire comprising 68 items across four subscales: pain and stiffness, social and emotional consequences, dysfunction, and activity limitation. Each item is scored from 1 to 4, with higher scores indicating poorer foot health and greater functional limitation. |
| Foot and Ankle Function (Foot and Ankle Outcome Score, FAOS) | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | The FAOS is a 42-item self-reported questionnaire assessing five subscales: pain, other symptoms, activities of daily living, sports and recreation, and foot-and-ankle-related quality of life. Each item is scored from 0 to 4. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Myofascial Tissue Biomechanical Properties | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | The biomechanical and viscoelastic properties of the plantar fascia, Achilles tendon, gastrocnemius medialis, soleus, biceps femoris, semitendinosus, tibialis anterior, vastus lateralis, vastus medialis, and rectus femoris will be assessed non-invasively using the MyotonPRO device (Myoton AS, Tallinn, Estonia). The device will be positioned perpendicular to the anatomical landmark of each muscle; upon delivery of a mechanical impulse, it automatically calculates muscle tone (Hz), stiffness (N/m), and elasticity (logarithmic decrement). The mean of three consecutive measurements will be recorded. |
| Plantar Fascia Ultrasonographic Parameters | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | Musculoskeletal ultrasonography (GE Logiq® P5 system; GE Healthcare, USA) will be used to evaluate structural changes. Plantar fascia thickness will be measured longitudinally at 0.5 cm, 1 cm, and 3 cm distal to the calcaneal insertion. Qualitative parameters, including tissue echogenicity, perifascial fluid accumulation, and calcifications, will also be recorded. |
| Ankle Dorsiflexion Range of Motion (ROM) | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | Weight-bearing ankle dorsiflexion ROM will be measured in degrees using a Baseline® 12-1057 digital inclinometer (0.1° resolution; Fabrication Enterprises Inc., USA), positioned parallel to the long axis of the tibia over the tibial tuberosity during a weight-bearing lunge test. The mean of three measurements will be recorded. |
| First Metatarsophalangeal (MTP) Joint Range of Motion | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | Maximum active dorsiflexion and flexion angles of the first MTP joint will be measured in degrees using a finger goniometer with the participant in a supine position. The mean of three measurements will be recorded. |
| Joint Position Sense (JPS) (Ankle-Knee and Hip) | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | Proprioceptive accuracy will be assessed at the ankle, knee, and hip joints via active joint position reproduction testing using a Baseline® 12-1057 digital inclinometer. For the ankle, participants will actively reproduce target dorsiflexion/plantarflexion angles. For the knee, participants will actively reproduce a target angle starting from 90° of flexion, with the inclinometer fixed to the middle third of the leg. For the hip, participants will actively reproduce target angles for flexion (assessed in supine position) and abduction (assessed in side-lying position), with the inclinometer fixed to the lateral aspect of the thigh. For each joint, the absolute error angle (the difference between the target angle and the actively reproduced angle) will be recorded across three trials, and the mean absolute error angle will be calculated as the outcome value. Lower values indicate better proprioceptive accuracy. |
| Isometric Muscle Strength of the Lower Extremity | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | Isometric muscle strength for ankle (dorsiflexion, plantarflexion) and knee (extension, flexion) movements will be measured using a Lafayette® Hand-Held Dynamometer (Model 01165; Lafayette Instrument Company, USA), with standardized testing positions and stabilization protocols. Peak force will be recorded in Newtons (N) as the mean of three maximal isometric contractions. |
| Static Balance | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | Static postural control will be assessed using the Single-Leg Stance Test (SLST) under eyes-open and eyes-closed conditions. The duration (in seconds) for which the participant maintains single-leg balance without touching the ground or the supporting leg will be recorded. Mean durations of three trials will be analyzed. |
| Dynamic Balance | Baseline (Week 0), post-intervention (Week 6), and follow-up (Week 12). | Dynamic balance and lower-extremity postural control will be evaluated using the Y-Balance Test (YBT). Maximum reach distances in the anterior, posteromedial, and posterolateral directions will be measured in centimeters and normalized to lower-limb length (LL). The composite score (%) will be calculated as: \[(Anterior + Posteromedial + Posterolateral) / (3 × LL)\] × 100. |
Countries
Turkey (Türkiye)
Contacts
CONTACTSule Kosar, MD
CONTACTAynur Basaran, Prof. MD
PRINCIPAL_INVESTIGATORAynur Basaran, MD, Prof.
Karamanoğlu Mehmetbey University
Outcome results
None listed