Predictive Measurement for Windlass Change in Length and Selected Treatment Outcomes in Chronic Plantar Fasciitis

Plantar fasciitis is characterized as an overuse syndrome involving localized inflammation of the plantar aponeurosis at its anatomical origin on the medial tubercle of the calcaneus¹. Although the exact cause is unknown, the prevailing opinion suggests that it arises from repeated partial tears and persistent inflammation within the plantar aponeurosis at its attachment point on the medial tubercle of the calcaneus². Plantar fasciitis has been theorized to result from weak plantar intrinsic or extrinsic muscles, which fail to provide adequate dynamic truss support for the longitudinal arch, thereby transferring additional tensile stress to the plantar aponeurosis. This excess tensile stress may lead to fatigue failure, triggering an inflammatory response and the formation of scar tissue, further shortening the tissue³.

While there is no gold standard diagnostic criterion for plantar fasciitis, the clinical presentation is widely recognized. Symptoms include pain and palpable soreness around the medial tubercle of the calcaneus, increased pain during the first few steps in the morning, and exacerbated pain with sustained weight-bearing. Despite extensive research efforts, foot surgeons continue to debate the cause, etiology, and optimal treatment strategy for plantar fasciitis⁴.

According to the windlass model, increased stresses on the first metatarsal head and hallux result in heightened tension in the medial slip of the plantar aponeurosis, offering a plausible explanation for the pain associated with plantar fasciitis. Pain may manifest in the aponeurosis or at its attachment to the bone when the aponeurosis is strained⁵. The windlass test stands out as the sole specialized diagnostic tool for detecting inflammation of the plantar fascia⁶. Using lateral radiography images of the foot in the loading position, the length of the plantar aponeurosis has been calculated as the distance between two bony markers: the calcaneal medial tuberosity and the base of the first metatarsal head⁷. The force generated by the contraction of the Achilles tendon serves as a reliable predictor of plantar aponeurosis tension^8,9.

Various conservative treatments, such as physical therapies, manual therapy, stretching exercises, and orthotic equipment, have been recommended for plantar fasciitis. Options also include taping, shoe adjustments, nonsteroidal anti-inflammatory drugs, cortisone injections, or combinations of these treatments¹⁰.

While there is no singular definitive treatment for plantar fasciitis, the condition can be managed in three stages: addressing the inflammatory lesion at the enthesis, correcting precipitating factors, and implementing a progressive rehabilitation program leading to a return to activity¹¹.

The objective of this study was to employ an objective, simple, and economical approach to measure the change in length of the windlass and assess the efficiency of a specified therapy protocol over a one-month period. The study investigated the response of patients with chronic plantar fasciitis to a treatment protocol involving structure-specific plantar aponeurosis stretching, Achilles tendon stretching, extrinsic and intrinsic foot muscle strengthening, a night splint, and the use of pulsed ultrasonic waves and an electrical heating pad. This regimen was selected based on clinical experience, with a significant percentage of patients reporting symptom relief. The hypothesis was that there is a correlation between clinical outcome measurements (tape and goniometer) and foot plantar pressure values, and that patients with chronic plantar fasciitis managed with this specific treatment protocol show improved outcomes after four weeks compared to measurements taken prior to treatment and those of normal subjects.

Participants
The study comprised two groups: one group included fifty patients diagnosed with unilateral plantar fasciitis, and another group consisted of fifty normal subjects. All patients were referred to the outpatient physical therapy clinic at Kasr Al-Aini Hospital by orthopaedic surgeons. Every patient experienced pain in the region where the plantar aponeurosis attaches to the medial tubercle of the calcaneus. In every instance, pain manifested when patients took their initial steps in the morning and intensified with weight-bearing activities throughout the day. Exclusion criteria encompassed patients diagnosed with spinal disorders, tarsal tunnel syndrome, cortisone injections in the heel area, or any pathology like hammer toe or hallux valgus, as well as anatomical abnormalities like pes cavus or pes planus that may predispose to the development of this condition, and the presence of a calcaneal spur. Patients with bilateral plantar fasciitis were also excluded. The mean age of the patients was 39.18 ± 5.43 years, with a gender distribution of 35 women and 15 men. The mean weight was 88.3 ± 11.46 kg, and the mean body mass index was 24.64 ± 32.76 kg/m². The mean duration between the onset of pain and admission to the study was 9 months.

This study was designed with a 1:1 matching, assigning one control for each patient, as 40% of individuals with unilateral plantar fasciitis develop symptoms in the contralateral limb¹². The control group was selected to compare the patients' measurements after treatment with those of normal subjects. Matching criteria included age, gender, weight, and body mass index. The control group comprised 50 subjects who reported never being diagnosed with plantar fasciitis and had no lower extremity injuries in the previous year or any abnormalities like pes cavus or pes planus. The control group was recruited from Kasr Al-Aini Hospital employment, with a mean age of 37.38 ± 38.6 years, a gender distribution of 36 women and 14 men, a mean weight of 88.94 ± 8.1 kg, and a mean body mass index of 24.5 ± 31.82 kg/m².

All procedures conducted in this study adhered to the pertinent guidelines and regulations of Helsinki 2013. Ethical approval was obtained from Kasr Al-Aini Hospital's ethical committee. The informed consent form was prepared in accordance with the standards set by the Ethics Committee of the hospital and obtained from the patients by the hospital's secretary, who played no role in this trial. Eligible patients were thoroughly informed about the interventions before signing the consent form. All subjects provided written informed consent prior to participating in the study, in accordance with Cairo University's ethics policy.

1. Patient preparation

1. Gather data variables for each subject, identified most frequently in the literature as potential risk factors for plantar fasciitis according to Riddle et al.¹³.
2. Calculate body mass index (BMI) using the formula BMI = weight (kg) / (height (m))².
3. Ask the patients to complete the foot function index pain subscale (FFI) questionnaire¹⁴.
   NOTE: The FFI pain subscale consists of 9 questions designed to assess the impact of foot pathology on function, specifically focusing on pain, for all patients.
4. Utilize a visual analog scale (VAS) for pain measurement¹⁵.

2. Measurement of windlass change in length

1. Visually assess patients and normal subjects (control group) for neutral foot type according to Dahle et al.¹⁶ classification.
2. Measure the windlass test range of motion for both patients and the control group from weight-bearing positions⁶.
   1. Measure the windlass change in length from the weight-bearing position for both groups using tape measurement, as suggested in this design. The reference points used for this length were the medial tubercle of the calcaneus (at the origin of the plantar aponeurosis) and the plantar plates of the 1^st metatarsophalangeal joint.
   2. Mark both sites with a skin marker and affix the tape to the medial tubercle of the calcaneus while the participant is in a sitting position.
   3. Instruct the patient to stand and extend the tape to the second point to minimize skin motion. The distance between the two points represents the windlass change in length, measured in centimeters.
   4. Conduct three consecutive measurements for tape measurement for each participant (patient and control), then calculate the mean value of the three measurements (Figure 1).
3. Measure the range of motion of the windlass mechanism, ankle dorsiflexion, and plantar flexion for both groups using a goniometer (see Table of Materials).
4. Evaluate foot plantar pressure recorded for patients and the control group under both static and dynamic conditions. Record subject details such as name, age, weight, and height. Record peak pressure values (kg/cm²) at eight regions: medial calcaneus, lateral calcaneus, first metatarsal, second metatarsal, third metatarsal, fourth metatarsal, fifth metatarsal, and big toe.
   NOTE: Calibration involves converting the raw digital output of the sensor to actual pressure (kg/cm²). Calibration was performed by having the subjects stand on the sensor with both feet briefly. Calibration was conducted before each new patient session, after the treatment protocol session, and for the control group as well.
   1. Perform static measurement^17,18.
      1. During static measurement, instruct the subjects to stand on the affected foot and focus on a fixed point on the wall, positioned 2 m away.
         NOTE: This assessment was conducted for both patients and normal subjects (control group). Three trials were recorded to ensure reliable pressure data.
   2. Conduct dynamic measurement.
      1. Instruct patients to walk barefoot at their natural speed and stop on the active surface of the platform with the affected foot only, without looking down at the platform across the plantar pressure platform embedded in a 100 cm walkway.
         NOTE: Highlight the importance of executing a regular step within the complete gait cycle, ensuring the maintenance of a normal walking speed and step length, and ensuring that the entire foot contacts the platform. After conducting several trials, designate a starting point that accommodates a three-step approach. Specifically, position the foot opposite to the one under examination to initiate the first step, with the test foot making contact with the platform on the second step from the established starting position.Use a two-step gait initiation protocol to collect foot pressure data^19,20.
      2. Record three trials for each subject, a number determined to ensure reliable pressure data.

3. Analysis of plantar pressure data

1. After data collection, determine peak pressure (kg/cm²) under eight regions of the foot^19,20: medial calcaneus, lateral calcaneus, 1^st metatarsal, 2^nd metatarsal, 3^rd metatarsal, 4th metatarsal, 5^th metatarsal, and big toe (Figure 2) using commercially available software (see Table of Materials).
   NOTE: Use the sum of the three trials under each point to calculate the mean peak pressure for each of the eight points.
2. Conduct post-treatment measurements at the same points and in the same manner for measurement and analysis of pressure distribution.
3. Treat patients with a clinical protocol of foot strengthening exercises.
   NOTE: Administer the Patient group a modified treatment protocol three times per week for four weeks, including the following:
   1. Apply pulsed ultrasound along the length of the plantar aponeurosis from the origin to the insertion on the medial compartment for 3 min at an intensity of 0.5 W/cm²/MHz.
   2. Apply a low-level electrical heating pad for 20 min under the entire foot.
   3. Instruct patients to perform manual stretching exercises for the Achilles tendon muscles from a non-weight-bearing position, weight-bearing self-stretching of the Achilles tendon muscles from a standing position using a slant board, and stretching exercises for the plantar aponeurosis.
   4. Instruct patients to perform manual strengthening exercises for the dorsiflexor and plantar flexor muscles, as well as strengthening exercises for intrinsic foot muscles using a rolled towel placed under the plantar aspect of the toes while seated, progressing to picking up the towel with the toes.
   5. Advise each patient to wear a night splint while sleeping and to remove the splint immediately upon waking in the morning, providing instructions on how to wear it.
4. Analyze the outcome measures, including pain, range of motion of dorsiflexion and plantar flexion, range of motion of the windlass mechanism, windlass change in length, and static and dynamic plantar pressure^19,20.

The Statistical Package for the Social Sciences (SPSS, see Table of Materials) was employed for all statistical procedures, as all outcome variables exhibited a normal distribution. Means, standard deviations, and standard errors were used as summary statistics. Analyses were conducted to examine differences in the general characteristics of participants (patients and control groups), including age, gender, weight, and body mass index. Differences in each dependent variable of interest (pain, windlass change in length, range of motion of dorsiflexion and plantar flexion, windlass mechanism, and static and dynamic pressure at the eight points beneath the foot) were compared pre-treatment and post-treatment using paired t-tests. Additionally, the control group and treatment group were compared for each variable using unpaired t-tests. Correlations among the windlass range of motion, windlass change in length, static and dynamic foot plantar pressure were explored using the Pearson product-moment correlation coefficient. A significance level of 0.05 and 0.01 was employed for all tests. Statistical power analysis was conducted prior to the study, determining that a sample size of fifty subjects per group would yield a test power of approximately 80% at significance levels of 0.05 and 0.01.

Participant characteristics
One hundred subjects who met the inclusion criteria were allocated to either the treatment group (fifty patients) or the control group (fifty normal subjects). To account for potential variations between the groups due to other factors, key variables crucial to the study's outcome (age, gender, weight, and body mass index) were assessed using an unpaired t-test, considering P values of ≤0.05 and ≤0.01 as statistically significant. Table 1 provides an overview of the baseline characteristics of the subjects who completed the study. The analysis of baseline measures for the two groups indicated a high degree of similarity in terms of age (P = 0.655), gender (P = 0.828), weight (P = 0.915), and body mass index (P = 0.287). An independent t-test for the general characteristics of participants revealed no significant differences between the two groups at significance levels of P ≤ 0.05 and P ≤ 0.01.

Comparison between patient group before and after the treatment
The patient group exhibited a statistically significant difference between pre- and post-treatment, as determined by a paired t-test. The changes in the outcome measures are detailed as follows: pain assessed using the visual analog scale (P = 0.000, T value 66.65); foot function index (FFI) (P = 0.000, T value 88.97); tape measurement of windlass change in length (P = 0.000, T value 13.56); windlass range of motion (P = 0.000, T value 20.82); dorsiflexion range of motion (P = 0.000, T value 13.81); and plantar flexion range of motion (P = 0.000, T value 16.49). A summary of the responses to the patients' relevant outcome measures, including pain, tape measurement, windlass range of motion, and dorsiflexion and plantar flexion range of motion, is presented in Table 2, and Figure 3 and Figure 4.

Foot plantar pressure during static and dynamic conditions
Plantar pressure was assessed before and after the treatment protocol for patients at the 1^st metatarsal, 2^nd metatarsal, 3^rd metatarsal, 4^th metatarsal, 5^th metatarsal, big toe, medial calcaneus, and lateral calcaneus points under both static and dynamic conditions. Statistically and clinically significant differences in plantar pressure were recorded, as summarized in Table 3, using a paired t-test (Figure 5 and Figure 6).

Comparison between the patient group after the treatment protocol and the control group
The results of the significance test for tape measurement of the windlass change in length, windlass range of motion, dorsiflexion, and plantar flexion range of motion were analyzed between both groups using an unpaired t-test. A P value of ≤0.05 and a P value of ≤0.01 demonstrated significant differences in windlass range of motion (P = 0.000) and T value (2.77), dorsiflexion range of motion (P = 0.000) and T value = 8.004, and plantar flexion range of motion (P = 0.000) and T value 4.66. However, no significant difference was found between the two groups with tape measurement of the length of the plantar aponeurosis (P value = 0.651 and T value = 0.454, Table 4).

Comparison between the patient group after the treatment and the control group at static and dynamic foot plantar pressure
Foot plantar pressure during static and dynamic conditions was compared using an unpaired t-test. The pressure data did not exhibit any statistical or clinical differences between both groups, as presented in Table 5.

Test of significance between the windlass and tape measurement
Statistical analyses were conducted using an unpaired t-test between windlass range of motion and tape measurement. The results showed no significant differences between windlass range of motion and tape measurement of windlass change in length before treatment in the patient group (T value = 0.683, P = 0.497), after the treatment (T value = -1.119, P = 0.266), and in the normal control group (T value = 0.612, P = 0.990).

Correlation between tape measurement and windlass at pre-treatment, post-treatment, and normal group values
The Pearson product-moment correlation coefficient between tape measurement and windlass at pre-treatment, post-treatment, and normal values was analyzed. The results showed a significant correlation between pre-windlass range of motion and pre-tape measurement (R = 0.293), a negative correlation between normal windlass range of motion and pre-tape (R = -0.361), a significant correlation between post-tape and pre-windlass (R = 0.404), and a negative correlation between normal windlass and post-tape measurement (R = -0.295), as presented in Table 6.

Correlation between static and dynamic foot plantar pressure with tape measurement and windlass range of motion
The Pearson product-moment correlation coefficient was employed to demonstrate the statistical relationship between foot plantar pressure (static and dynamic), tape measurement, and windlass range of motion. Pre-treatment tape correlated negatively with pre-1^st static metatarsal plantar pressure (R = -0.401 at P≤ 0.01), dynamic normal medial calcaneus pressure (R = 0.331 at P≤ 0.05), and dynamic normal lateral calcaneus pressure (R = 0.306 at P≤ 0.05). Normal tape measurement correlated with pre-static 4^th metatarsal pressure (R = 0.288 at P≤ 0.05), post-static 2^nd metatarsal (R = 0.331 at P≤ 0.05), post-static 4^th metatarsal (R = 0.337 at P≤ 0.05), and post-static big toe (R = 0.337 at P≤ 0.05). Post-tape measurement correlated with dynamic normal medial calcaneus pressure (R = 0.279 at P≤ 0.05). Windlass range of motion for the normal group correlated negatively with dynamic normal medial calcaneus pressure (R = -0.289 at P≤ 0.05), and pre-windlass range of motion correlated positively with post-3^rd static plantar pressure (R = 0.319 at P≤ 0.05, refer to Table 7).

Figure 1: Assessment of windlass change in length. The Windlass test range of motion was measured for patients and control groups in weight-bearing positions. Please click here to view a larger version of this figure.

Figure 2: Analysis of plantar pressure results. Foot plantar pressure was recorded for patients under static and dynamic conditions. Data regarding subjects, including name, age, weight, and height, were recorded. Calibration, converting the raw digital output of the sensor to actual pressure (e.g., Kg/cm²), was performed by having subjects stand on the sensor with both feet for a moment. Calibration occurred before each new patient session and after the treatment protocol session. Please click here to view a larger version of this figure.

Figure 3: VAS mean value before and after treatment. VAS mean value was determined utilizing a Visual Analog Scale (VAS) for pain measurement. Please click here to view a larger version of this figure.

Figure 4: FFI mean value before and after treatment. This was evaluated after the completion of a Foot Function Index pain subscale (FFI) questionnaire. The FFI pain subscale consists of 9 questions measuring the impact of foot pathology on function in terms of pain for all patients. Please click here to view a larger version of this figure.

Figure 5: Mean static pressure under the Medial Calcaneus (MC) for pre- and post-treatment and control group. During static measurement, subjects were instructed to stand on the affected foot and look at a constant point on the wall, 2 m away. Evaluation was performed for patients and normal subjects, with three recorded trials ensuring adequate reliability of pressure data. Please click here to view a larger version of this figure.

Figure 6: Mean dynamic pressure under the Medial Calcaneus (MC) for pre- and post-treatment and control group. Patients underwent training to walk barefoot at their natural pace and halt on the active surface of the platform, using only the affected foot and refraining from looking down. This occurred over the plantar pressure platform embedded in a 100 cm walkway. It was ensured that a standard step in the full gait was maintained, incorporating normal walking speed, step length, and complete foot contact with the platform. Following multiple trials, a starting point was selected to facilitate a three-step approach. The starting position was established so that the first step involved the foot opposite to the one being assessed, and the test foot connected with the platform on the second step from the starting position. Utilizing a two-step gait initiation protocol, foot pressure data were collected. Each subject underwent three recorded trials to ensure sufficient reliability of pressure data. Please click here to view a larger version of this figure.

Table 1: General characteristics of participants. Please click here to download this Table.

Table 2: Results for the test of significance for VAS, FFI, tape measurement, and range of motion of windlass, dorsiflexion, and plantar flexion for patients before and after the treatment program. Please click here to download this Table.

Table 3: Results for the test of significance for static and dynamic foot plantar pressure for patients before and after the treatment. Please click here to download this Table.

Table 4: Comparison between the patient's group after treatment and the control group. Please click here to download this Table.

Table 5: Comparison between the patient's group after the treatment program and the control group at static and dynamic foot plantar pressure. Please click here to download this Table.

Table 6: Pearson product-moment correlation coefficient between measures of windlass. Please click here to download this Table.

Table 7: Pearson product-moment correlation coefficient between measures of windlass range of motion, tape measurement, and foot plantar pressure. Please click here to download this Table.

The outcomes for individuals with persistent plantar fasciitis are generally positive, with conservative therapy showing success rates ranging from 46% to 100%¹. Prolonged issues may lead to additional treatments, including surgery, but the recovery time is often lengthy and may not allow for full function²¹. Therefore, optimizing nonoperative therapy is crucial before considering surgical options. Despite its chronic nature, most nonoperative therapies for plantar fasciitis have demonstrated positive or encouraging findings. Treatment options include rest²², appropriate footwear²³, therapeutic ultrasound²⁴, low-intensity laser²⁵, iontophoresis with corticosteroid²⁶, night splints^27,28, foot orthosis^29,23, low dye taping³⁰, non-steroidal anti-inflammatory medications²², and extracorporeal shock wave therapy (ESWT)³¹.

Stretching exercises² and exercises for strengthening²⁸, or a combination of these modalities^2,32, are recommended. Night splints, in particular, have shown favorable effects in many studies⁴. These splints are designed to maintain the ankle in a neutral position overnight, facilitating passive calf and plantar stretching while sleeping. This approach allows for healing while the plantar aponeurosis is in an extended position, reducing strain with the first step in the morning. However, it is worth noting that night splints may cause slight discomfort, impacting sleep for the patient or their bed partner, as reported by patients in this study. Given that heat tends to elevate the pain threshold, lowering discomfort³³, it was employed as a therapeutic technique in this study. Therapeutic ultrasound was also used to treat plantar fasciitis, although the literature on its efficacy has yielded contradictory results regarding the clinical benefits of ultrasound waves for plantar heel pain²⁴. The primary goals of the protocol were to restore the windlass mechanism and reduce recurrent microtrauma and related chronic inflammatory processes. A program of plantar aponeurosis-specific stretching exercises was found to outperform a typical program of weight-bearing Achilles tendon-stretching activities for treating plantar fasciitis symptoms^2,34.

This study associates the clinical manifestations observed in plantar fasciitis, such as morning pain or discomfort after periods of rest, with fascial damage and subsequent contracture of the Achilles tendon and intrinsic muscles. The pain is attributed to the combination of muscular contraction and gravitational forces, causing the aponeurosis to be held in a shortened position. The healing process is interrupted when the patient stands, and the fascia is stretched back to its original length, perpetuating a repetitive cycle. This cycle is responsible for the pain and swelling evident during examinations.Therefore, the primary goal of treatment should be directed at placing the aponeurosis at the proper length to facilitate healing in both weight-bearing and non-weight-bearing activities³⁵. There exists a biomechanical relationship between the force in the Achilles tendon and the strain generated in the plantar aponeurosis, influenced by the metatarsophalangeal joint dorsiflexion angle³⁶. This relationship is evident in the increasing measurements of the length of the plantar aponeurosis, weight-bearing range of motion of the windlass, and range of motion of dorsiflexion and plantar flexion of the ankle joint.

Achilles tendon contractures shift plantar weight-bearing pressure from the hindfoot to the forefoot. Consequently, forefoot pressure significantly decreases after Achilles tendon lengthening³⁷. This evidence supports the study's results, indicating a decrease in forefoot pressure (1^st ,2^nd, 3^rd, 4^th, 5^th metatarsal) and an increase in hindfoot pressure (lateral and medial calcaneus) after the treatment program, which included stretching of the Achilles tendon. Additionally, there was an increase in the dorsiflexion range of motion of the ankle joint. This indicates that normal plantar soft tissue can deflect a load away from the most exposed parts of the metatarsal heads more efficiently with increasing dorsiflexion of the toes, aligning with previous findings³⁸.

The strengthening exercise protocol employed in this study offers two key advantages. Firstly, it reduces the additional tensile stress on the plantar aponeurosis, and secondly, it enhances the effectiveness of the windlass mechanism. While the study was not designed to measure the muscular power of foot muscles, the results indicate a notable association between the strengthening exercise program and muscular power. The mean range of motion for the windlass, dorsiflexion, and plantar flexion significantly increased after the treatment protocol. Furthermore, significant differences were observed in the range of motion after treatment when compared with the control group (P = 0.000, where P ≤ 0.01) for patients with chronic plantar fasciitis. These findings underscore the efficacy of the foot strengthening exercise protocol.

To the best of our knowledge, this treatment protocol represents the first prospective matched clinical trial assessing the response to a different modality protocol in subjects with chronic plantar fasciitis and comparing the results with normal subjects. The hypothesis, based on clinical measurements, suggested that a substantial proportion of 96% of patients experienced complete resolution of symptoms in response to the treatment protocol used in this study.

The criteria for evaluation were meticulously chosen to precisely gauge the impact of the protocol on various aspects, including pain levels, range of motion in weight-bearing windlass, dorsiflexion and plantar flexion in the ankle joint, tape measurement of windlass change in length, and measurements of foot plantar pressure. The study aimed to investigate the relationship between clinical measurements (tape measurement and goniometric measurement) and foot plantar pressure analysis. Additionally, it explored whether clinical measurements (tape measurement and goniometric measurement of the windlass mechanism) could serve as an objective method to evaluate plantar fasciitis and document a patient's response to the suggested treatment program. At the time of the study, there was no published description of whether the tape measure length of the plantar aponeurosis is used in vitro, making it challenging to compare this type of measurement with others. However, numerous in vivo studies have documented the elongation of the plantar aponeurosis. The plantar aponeurosis is known to elongate from toe dorsiflexion 0 degrees to 45 degrees in a weight-bearing condition to reach a normal strain of almost 8.26%³⁸.

Significant differences were observed between patient groups before and after treatment at P≤ 0.01 and P ≤ 0.05 in the length of the plantar aponeurosis, correlating with the signs and symptoms of plantar fasciitis. However, no significant differences were found between the patient group after treatment and the control group (P = 0.651). The weight-bearing goniometric measurement of the windlass mechanism was considered the only specific objective test to diagnose plantar fasciitis by De Garceau et al.⁶.

The tape measurement method employed in this study aimed to measure the windlass change in length. The study made efforts to minimize skin motion during tape treatment by utilizing weight-bearing positions during measurements to reduce the potential for error. Pain assessment was conducted using the Visual Analog Scale (VAS) due to its recognized validity and reliability in measuring plantar fasciitis pain, as indicated by Hyland et al.³⁹. The Foot Function Index's pain subscale was chosen for its validation as an instrument, as per Ibrahim et al.⁴⁰.

The decrease in the range of motion of the windlass mechanism observed in the study may be attributed to abnormalities in the connective tissues of the joint and increased tension of the plantar aponeurosis⁴¹. The mean range of motion of the windlass mechanism in the patients was recorded as 19.8°. Plantar pressure measurement was employed as an objective tool to aid in the diagnosis and treatment of foot pathology⁴².

The study measured plantar pressure distribution under eight regions of the foot (1^st metatarsal, 2^nd metatarsal, 3^rd metatarsal, 4^th metatarsal, 5^th metatarsal heads, big toe, medial calcaneus, and lateral calcaneus) during both standing and walking. The findings indicated increased peak pressure in the forefoot regions during static and dynamic measurements in the patient group. A higher proportionate load was observed in the forefoot. These results were highly significant for all eight regions after the treatment program during static and dynamic measurements (P = 0.0000). When comparing the control group with the patient group after the treatment protocol, no significant differences were observed at any of the measured points during static or dynamic measurements. The highest mean values of peak pressure distribution were found under the heel, the second and third metatarsal heads, and the hallux. These results align with previous studies by Cavanagh et al.⁴³, Oats⁴⁴, Rodgers⁴⁵, and Bryant et al.¹⁹.

The study's findings provide valuable insights into the typical presentation of plantar fasciitis, often characterized by increased plantar pressure under the forefoot. Additionally, individuals with plantar fasciitis exhibited lower plantar pressure under the calcaneus in both static and dynamic situations, likely attributed to discomfort and tendon shortening. Maintaining consistency in measuring techniques is crucial, given that various factors such as equipment used, cadence, step length, and walking pace can impact plantar pressure measurements. Moreover, the reliability and reproducibility of measurements obtained using testing equipment must be satisfactory. In this study, a single recording achieved a good level of reliability for most pressure variables, and when the mean result of three or more trials was considered, the reliability was found to be excellent¹⁹. The study adhered to these conditions, ensuring robust and reliable measurements.

The study effectively utilized objective measures by establishing correlations between foot plantar pressure assessments (static and dynamic), weight-bearing range of motion measurements, and tape measurements using the Pearson product-moment correlation coefficient (Table 7). Several noteworthy correlations were identified: (1) A strong negative correlation was found between pre-tape measurement and pre-static measurement of the 1st metatarsal, R = -0.401 at P≤ 0.01; (2) Positive correlations were observed between pre-tape measurement and normal dynamic measurements of both medial calcaneus (R = 0.311 at P≤ 0.05) and lateral calcaneus (R = 0.306 at P≤ 0.05); (3) Post-tape measurement demonstrated a positive correlation with dynamic pressure measurement of normal medial calcaneus, R = 0.279 at P≤ 0.05. (4) Normal tape measurement exhibited positive correlations with various static measurements, including the 4^th metatarsal (R = 0.288 at P≤ 0.05), 2^nd metatarsal (R = 0.331 at P≤ 0.05), big toe (R = 0.337 at P ≤ 0.05), and 4^th metatarsal again (R = 0.337 at P≤ 0.05); (5) Pre-windlass measurement was positively correlated with post-static 3rd metatarsal, R = 0.319 at P ≤ 0.05; (6) Normal windlass measurement passively correlated with normal dynamic medial calcaneus measurement, R = 0.289 at P≤ 0.05. These findings suggest that measurements related to the windlass mechanism, such as its range of motion and tape measurement of windlass change in length, offer valuable insights into plantar pressure magnitude. These measures may prove to be more informative in identifying individuals at a higher risk of developing plantar fasciitis.

This study provides valuable insights into the measurement of range of motion in plantar fasciitis, emphasizing the significance of weight-bearing measurements and tape measurements as important indicators. The use of goniometric measurement, a validated instrument, adds credibility to the evaluation of range of motion⁴⁶. Quantitative plantar pressure assessment is highlighted as a crucial aspect in understanding foot issues, particularly in the context of plantar fasciitis. While not yet a standard feature in treatment, the study suggests that the financial commitment to acquiring and using such equipment could be minor compared to the potential health benefits. The goal of the study is to contribute to the development of a simple instrument that can complement routine plantar fasciitis care practices.

The study also addresses a common concern among individuals seeking treatment for plantar fasciitis - the pace of improvement. The results indicate that using a combination of therapeutic modalities, including pulsed ultrasound, electrical heating pad, stretching exercises for the plantar aponeurosis and Achilles tendon, as well as strengthening exercises for foot muscles, along with the use of a night splint, led to a remarkable 96% of patients experiencing complete resolution of symptoms associated with plantar fasciitis.

It is noteworthy to highlight a significant clinical impact on plantar fasciitis, a structure akin to a tendon. Currently, there is a dearth of biological studies on the plantar fascia. Notably, the analgesic effect of Extracorporeal Shock Wave Therapy (ESWT) is comparable to that of autologous blood-derived products in the medium term (6 months). Moreover, within the spectrum of ESWT, the success rate is notably higher with medium- and high-intensity ESWT⁴⁷.Studies on chronic and recurrent pain using different mechanisms offer heterogeneous results that must be validated and standardized⁴⁸.

Despite current advances in diagnostic technologies, the diagnosis of plantar fasciitis primarily relies on medical history and clinical presentation. Clinicians should periodically assess windlass length changes to ensure mechanical control of the foot. The current study's findings indicate a substantial relationship between tape measurement windlass change in length, weight-bearing windlass range of motion, and foot plantar pressure measurement. The comparison of participants validated the efficiency of tape measuring and goniometric windlass mechanism measurement as economical and simple techniques of evaluation in clinical settings. The study design shifts focus towards the nonoperative treatment alternative, yielding a remarkable 96% rate of improvement and complete resolution of symptoms within the patient group. This surpasses the response observed with more conventional treatment approaches for individuals dealing with chronic plantar fasciitis. However, it is essential to acknowledge the limitations of this study, including its small sample size and the relatively brief follow-up period. Future investigations would benefit from larger sample sizes and the exploration of diverse treatment methodologies.