Evaluation of the efficacy of trigger points combined with extracorporeal shock waves in the treatment of plantar fasciitis: heel temperature and plantar pressure

doi:10.21203/rs.3.rs-3247285/v1

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Research Article

Evaluation of the efficacy of trigger points combined with extracorporeal shock waves in the treatment of plantar fasciitis: heel temperature and plantar pressure

https://doi.org/10.21203/rs.3.rs-3247285/v1

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published 02 Mar, 2024

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Background

Plantar fasciitis (PF) is the most common cause of heel pain. Among several conservative treatments, extracorporeal shock wave therapy (ESWT) is considered an effective treatment for refractory plantar fasciitis. Studies have shown that the trigger points (TrPs) in the triceps surae of ESWT may play an important role in the treatment of pain in PF patients. Therefore, the purpose of this study was to evaluate the efficacy of extracorporeal shock waves combined with TrPs in patients with PF by using heel temperature and plantar pressure based on the concept of trigger pointsand ESWT.

Methods

According to the inclusion and exclusion criteria, 86 patients with plantar fasciitis were recruited from the pain clinic of Huadong Hospital, Fudan University. They were randomly divided into an experimental group (n = 43) and a control group (n = 43). The experimental group was treated with extracorporeal shock waves to treat the medial heel pain point combined with the gastrocnemius and soleus trigger points. The control group was only treated with extracorporeal shock waves to treat the medial heel pain point. The two groups were treated twice, with an interval of 1 week. Primary measurements included anumerical rating scale (NRS) (overall, first step, heel pain during daily activities), andsecondary measurements included heel temperature, Roles and Maudsley score (RMS), and plantar pressure. All assessments were performed before treatment (i.e., baseline) and 6 and 12 weeks after treatment.

Results

During the trial, 3 patients in the experimental group withdrew from the study, 2 patients withdrew from the study due to the interruption of the course of treatment affected by the new coronavirus epidemic, and 1 patient withdrew from the study due to personal reasons. In the control group, 3 patients fell and were removed due to swelling of the heel. Therefore, only 80 patients with PF were finally included. After treatment, the two groups showed good results in NRS (overall, first step, heel pain during daily activities), Roles and Maudsley score (RMS), and plantar temperature, especially in the experimental group. The effect was significantly better than that in the control group.

Conclusion

ESWT of the heel combined with the triceps trigger point of the calf can more effectively improve the pain, function and quality of life of refractory PF than ESWT of the heel alone. In addition, the ESWT of the heel combined with the triceps trigger point of the calf can effectively reduce the skin temperature of the heel on the symptomatic side, indicating that the heel temperature measured by infrared thermal imaging may be used as an independent tool to evaluate the therapeutic effect of patients with chronic plantar fasciitis. Although extracorporeal shock waves combined with TrPs treatment can cause changes in the gait structure of patients, plantar pressure is still difficult to use as an independent tool to evaluate the therapeutic effect of plantar fasciitis.

Trial registration Registered in the Chinese Clinical Trial Registry (www.chictr.org.cn) on12/17/2021 with the following code: ChiCTR-INR-2100054439.

plantar fasciitis

infrared thermal imaging

shock wave

plantar pressure

Plantar fasciitis is a chronic musculoskeletal aseptic inflammation secondary to repeated stress on the plantar fascia at the medial calcaneal eminence at its starting point^[1]. In most cases, plantar fasciitis is a self-limiting disease, but complete remission of symptoms may take up to 1 year^[2].

Plantar fasciitis can be treated by surgery or conservative treatment^[3]. Due to the large trauma of surgical treatment and the risk of postoperative complications, conservative treatment is the first choice in clinical practice^[4]. Conservative treatment is effective for approximately 90% of patients^[5]. Conservative treatment includes nonsteroidal anti-inflammatory drugs, plantar corrective insole, physical therapy, stretching, corticosteroid injection, etc. Among them, extracorporeal shock wave therapy is considered the main means of conservative treatment of PF and provides substantial symptom relief for most patients^[6]. However, most of the ESWT schemes that are usually used to treat plantar fasciitis only focus on the plantar fascia, without considering the tension of the entire lower limb. The curative effect is often short.

At present, a relationship between trigger points and PF symptoms has been found^[7–9]. TrPs are sensitive nodules in the muscle or fascia that are painful when palpated, resulting in distal referred pain and autonomic nerve response^{[8, 10]}. TrPs are mainly formed by excessive use of skeletal muscle and are divided into two states: activated or recessive. Activated TrPs cause local area pain and referred pain, while recessive TrPs require mechanical stimulation to cause pain^{[8, 11]}. At present, there are few studies on extracorporeal shock waves combined with trigger points in the treatment of PF. Commonly used evaluation methods, such as the digital scoring method, are subjective and cannot objectively reflect the therapeutic effect^{[12, 13]}.

Some studies suggest that PF may be caused by inflammation^[14], and the presence of TrPs will induce excessive excitation of the sympathetic nerve. The main function of the sympathetic nerve is to regulate blood vessels, resulting in local skin temperature changes^[15]; The increase and decrease of temperature can be used to reflect the reduction or aggravation of inflammation. Other studies suggest that PF may be caused by high tension stimulation of the plantar fascia overload, and the presence of TrPs will cause higher tension than that in normal tissue^[12]. Therefore, the purpose of this study was to explore whether changes in inflammation and plantar pressure can be expressed by heel temperature to understand the improvement in foot tension. We hypothesized that heel temperature and plantar pressure can be used to evaluate the efficacy of extracorporeal shock waves combined with TrPs in PF patients.

Study design

A single-blind trial with 12 weeks of follow-up with parallel groups was carried out from August 2021 to August 2022. The study was conducted according to the principles of the Helsinki Declaration and approved by the Ethics Committee of Huadong Hospital Affiliated to Fudan University: No. 2021K109. This randomized controlled trial (RCT) has been registered at the Primary Registry of International Clinical Trial Registry Platform World Health Organization “Chinese Clinical Trial Registry” [ChiCTR2100054439]. Before participating in the project, the purpose of the study was explained to all patients, and written informed consent was obtained from all patients.

Sample Size

Due to the lack of previous studies, this study estimated the sample size through a preexperiment. In addition, this study is a randomized controlled trial of a parallel design, with a numerical rating scale (NRS) as the main observation index, which is a continuous variable. The sample size was calculated by PASS 15 software. The test level parameter was set to α = 0.05 (bilateral), and the test efficiency parameter was set to 1-β = 80%. The minimum sample size required for the experimental group and the control group was calculated as N1 = N2 = 23 cases. The exit rate is 20%, so at least 29 people should be included in each group.

Participants

A total of 118 participants were assessed for eligibility. Eighty-six patients with PF were recruited from the Department of Pain Management, Huadong Hospital affiliated with Fudan University. All of the patients refused to undergo any surgery and signed informed consent forms. The CONSORT flow diagram for the RCT to evaluate the efficacy of extracorporeal shock waves combined with TrPs in patients with PF is illustrated in Fig. 1.

According to the inclusion criteria and exclusion criteria, they voluntarily participated in the experiment. The inclusion criteria were as follows: 1.18 years of age or older; 2. heel pain ≥ 3 months; and 3. Clinical examination confirmed plantar fasciitis, with an NRS ≥ 5 points; 4. The preferred conservative treatment (nonsteroidal anti-inflammatory drugs and/or other analgesics, exercise programs, insoles) was ineffective; and 5. signed informed consent. The exclusion criteria were as follows: 1. Previous history of ankle and foot fracture or surgery, foot and ankle infection, or history of lower limb tumor; 2. Lower extremity neurological dysfunction; 3. Patients with rheumatic diseases and metabolic diseases; and 4. Local injection of steroids or surgical treatment within three months.

Randomization and blinding

A total of 86 patients who fulfilled the inclusion criteria were randomly assigned (1:1 ratio) to the two experimental groups, the control group or the control group by an independent researcher using Microsoft Excel 2010 via computerized random numbers^[16]. An independent researcher who was not involved in the recruitment, assessment, or intervention process conducted the randomization and was blinded to the group allocation. Participants were also instructed not to reveal their group assignment. Sequentially numbered sealed envelopes were used for allocation. The envelopes were opened only by the researcher responsible for applying the treatment programs. The patients were randomly divided into two groups: group A (experimental group), in which the treatment target was selected at ipsilateral trigger points (gastrocnemius and soleus trigger points) and heel medial area pain points, and group B (control group), in which the treatment target was selected at the pain point in the medial area of the affected heel. Both groups were treated with the Swiss storz radiation shock wave, and the energy flux density is usually considered the main variable reflecting the physical and biological effects to maintain the consistency of treatment. A total of 3,000 shocks (0.16 mJ/mm²) with a 15 mm treatment probe were selected. 8 Hz), and the treatment intensity was 1.4 bar.

Outcome measures

Patients were measured and evaluated by a single person to reduce errors. All patients were required to undergo digital scoring (NRS), Roles and Maudsley scores (RMS), infrared thermal imaging to measure heel temperature and plantar pressure assessment before treatment (i.e., baseline) and 6 weeks after treatment, and digital scoring (NRS), Roles and Maudsley scores (RMS) and infrared thermal imaging to measure heel temperature assessment at 12 weeks after treatment.

Primary outcome measures

The NRS scale was used to evaluate the overall heel pain, heel pain at the first step, and heel pain during daily activities in PF patients. A score of 0 was divided into no pain, 1–3 was divided into mild pain, 4–6 was divided into moderate pain, and 7–10 was divided into severe pain.

Secondary outcome measures

The Roles and Maudsley scores (RMS) were used to assess the patients' subjective satisfaction. An RMS score of 1 point indicates an excellent quality of life, an RMS score of 2 points indicates a good quality of life, an RMS score of 3 points indicates an acceptable quality of life, and an RMS score of 4 points indicates a poor quality of life.

The heel temperature was measured by infrared thermal imaging, and the affected heel area was divided into 5 regions of interest according to the anatomical structure of the plantar surface (Fig. 2), and the average temperature of the 5 regions of interest was recorded, which were outer/upper, position 1 ; outside/down, position 2 ; inside/above, position 3 ; inside/under, position 4 ; and central, location 5. The average temperatures of the five regions of interest were recorded as T1, T2, T3, T4 and T5.

Through the plantar pressure plate instrument, the plantar pressure data in the static state and walking state were collected, including the average pressure of the static plantar (forefoot and hindfoot), the maximum pressure of the static plantar (forefoot and hindfoot) and the dynamic plantar inner and outer loads.

Interventions

Experimental group

According to the internationally recognized three principles of trigger point positioning theory, the following were used for location: 1. palpable skeletal muscle on the tight band nodules; 2. There are obvious tenderness points on the tight bandage; and 3. The symptoms of the patient's pain reappeared during palpation. If a point satisfies the above three points, it is considered an active trigger point. If it satisfies both 1 and 2 but does not satisfy 3, it is considered an implicit trigger point^[8]. The patient's gastrocnemius muscle, soleus muscle activity and hidden trigger points were identified and marked with a medical sterile surgical marker pen. Swiss Storz-MP200 extracorporeal shock wave therapy was used once a week for a total of 2 treatments. The trigger points of the triceps surae and the pain points in the medial area of the heel were taken as the treatment points. Each patient was placed in a prone position, and the patient’s hands were placed on the side of the body to fully expose the affected leg and heel. The coupling agent was applied at the specified position, the leg was subjected to vertical impact, the heel was subjected to lateral impact, and 300 impacts were applied at each trigger point.

Control group

The subjects were treated with Swiss Storz-MP200 extracorporeal shock wave therapy at the medial heel pain point after palpation to determine the medial heel tenderness point; the course of treatment, frequency and dose were the same as those of the experimental group.

Statistical analysis

Statistical Package for Social Science 23.0 was used for statistical analysis. The continuous variables that conform to the normal distribution are expressed as the mean and standard deviation. The K-S test was used to test whether the data obey the normal distribution. If the data obeyed a normal distribution, the independent t test was used. If the data did not obey a normal distribution, a nonparametric test was used, and the Mann‒Whitney U test was used for pairwise comparisons. Categorical variables are expressed as frequencies and composition ratios, and the chi-square test was used to compare groups. The repeated measurement efficacy indicators that met the normal distribution and homogeneity of variance were analyzed. Mauchly was used for the sphericity test. If the sphericity test was passed, a two-factor analysis of variance was used. If the sphericity test was not passed, the Greenhouse‒Geisser method was used for result correction. In the results of repeated measures analysis of variance, if there is no interaction effect between time and treatment factors, the main effect test is directly used to evaluate the effect of treatment factors. If there is an interaction effect between time and treatment factors, the individual effect should be analyzed; that is, the intragroup effect should be analyzed by one-way repeated measurement analysis of variance, and the intergroup effect should be analyzed by multivariate analysis of variance. P < 0.05 indicated that the difference was statistically significant, and P < 0.01 indicated a significant difference.

Baseline characteristics

A total of 86 patients were included in this study. During the test, 3 patients in the experimental group withdrew from the study, 2 patients withdrew from the study due to the interruption of the course of treatment affected by the new coronavirus epidemic, and 1 patient withdrew from the study due to personal reasons. In the control group, 3 patients fell and were removed due to swelling of the heel. Finally, a total of 80 patients completed the trial. There were 30 male patients and 50 female patients. There was no significant difference in demographic and clinical characteristics, such as age, sex, height and weight, between the two groups (p > 0.05), indicating that the data of the two groups were comparable (see Table 1).

Table 1

Baseline characteristics (n = 80, mean ± SD)
Features	Control group, n = 40	Test group, n = 40	P value
Age (yrs), Mean (SD)	48.03 ± 15.27	53.20 ± 13.97	0.118
Sex (M/F), N	14/26	16/24	0.644
Height (m), Mean (SD)	165.23 ± 7.73	165.28 ± 8.74	0.978
Body weight (kg), Mean (SD)	67.33 ± 10.59	65.54 ± 9.78	0.435
BMI (kg/m²), Mean (SD)	24.61 ± 3.06	23.95 ± 2.72	0.311
Affected side (right/left),N	21/19	21/19	1.000
Duration of pain (months), Median [IQR]	12 (7.25-24.00)	9 (5.25–17.25)	0.315
Note : sD : standard deviation ; BMI: Body Mass Index; [ IQR ] : [ interquartile range ] ; according to the normality test, continuous variables were expressed as Mean ± SD or Median [ IQR ]. Gender is a categorical variable, and N is used to represent the value. Experimental group : pain points combined with TrPs treatment. Control group : pain point treatment.

The main effect test of the overall NRS score, the NRS score of heel pain at the first step, and the NRS score of heel pain during daily activities during the treatment period of the two groups of patients.

The overall NRS score, heel pain NRS score at the first step, and heel pain NRS score during daily activities of the two groups of patients all met the normal distribution and homogeneity of variance (p > 0.05). After Mauchly's spherical hypothesis test, the covariance matrix of the dependent variable variance was equal, so the results did not need to be corrected by the Greenhouse‒Geisser method.

The results of the overall NRS score, the heel pain NRS score at the first step, and the heel pain NRS score during daily activities of the two groups of patients showed that the time effect was statistically significant (F = 318.328, p < 0.001; F = 999.165, p < 0.001; F = 1058.978, p < 0.001), which reflects that the overall NRS score, heel pain NRS score at the first step, and heel pain NRS score during daily activities of the two groups of patients change over time. There were statistically significant differences in the intergroup effects of the overall NRS score, the NRS score of heel pain at the first step, and the NRS score of heel pain during daily activities between the two groups (F = 20.507, p < 0.001). F = 13.438, p = 0.001; F = 11.152, p < 0.001), which reflects the differences in the overall NRS score, the NRS score of heel pain at the first step, and the NRS score of heel pain during daily activities between the experimental group and the control group. The interaction effects of the overall NRS score, heel pain NRS score at the first step, and heel pain NRS score during daily activities were statistically significant between the two groups (F = 5.452, p = 0.006; F = 7.724, p = 0.001; F = 8.431, p < 0.001), indicating that the influence of time factors on the overall NRS score, the NRS score of heel pain at the first step, and the NRS score of heel pain during daily activities varies with different treatment methods. Therefore, a separate effect should be used to test the time effect and intergroup effect of the two groups of patients. (See Table 2)

The single effect test of the total NRS score, the NRS score of heel pain at the first step, and the NRS score of heel pain during daily activities in the two groups during the treatment period.

The intragroup comparison included the overall NRS score, heel pain NRS score at the first step, and heel pain NRS score during daily activities of PF patients in the experimental group and the control group at 6 weeks and 12 weeks after treatment. The results showed that compared with before treatment, the overall NRS score, heel pain NRS score during daily activities, and heel pain NRS score at the first step of the two groups decreased at 6 weeks and 12 weeks after treatment (p < 0.001).

Comparison between groups: The overall NRS score, the NRS score of heel pain at the first step, and the NRS score of heel pain during daily activities at 6 and 12 weeks after treatment in the experimental group were lower than those in the control group (p < 0.001). (See Table 2)

Table 2

NRS scores during treatment in both groups (n = 80, mean ± SD)
Index	Peer group	Pretreatment baseline	Posttreatment		F,P(time)	F,P(between groups)	F,P(interaction)
Index	Peer group	Pretreatment baseline	6 week	12 week	F,P(time)	F,P(between groups)	F,P(interaction)
overall NRS score	Control group(n = 40)	7.13 ± 0.69	3.65 ± 0.86^*	4.18 ± 0.78^*#	F = 318.328, P < 0.001	F = 20.507, P < 0.001	F = 5.452, P = 0.006
	Test group(n = 40)	7.08 ± 0.80	2.95 ± 0.78^*&	3.3 ± 0.91^*#&
	t	0.301	3.798	4.611
	P	0.764	< 0.001	< 0.001
heel pain at first step	Control group(n = 40)	7.30 ± 0.76	3.73 ± 0.85 ^*	3.93 ± 0.83 ^*△	F = 999.165, P < 0.001	F = 13.438, P = 0.001	F = 7.724, P = 0.001
	Test group(n = 40)	7.28 ± 0.82	3.03 ± 0.73^*&	3.13 ± 0.79^*#△
	t	0.142	3.952	4.418
	P	0.887	< 0.001	< 0.001
heel pain with daily activities	Control group(n = 40)	7.20 ± 0.79	3.48 ± 0.78 ^*	3.98 ± 0.77 ^*#	F = 1058.978, P < 0.001	F = 11.152, P < 0.001	F = 8.431, P < 0.001
	Test group(n = 40)	7.23 ± 0.66	2.88 ± 0.69^*&	3.25 ± 0.87^*#&
	t	-0.154	3.642	3.953
	P	0.878	< 0.001	< 0.001

* indicates p < 0.001 compared to pretreatment, # indicates p < 0.05 compared to 6 weeks posttreatment; ^△indicates p＞0.05 compared to 6 weeks posttreatment; & indicates p < 0.001 compared to the control group.

4.3 Comparison of roles and Maudsley scores before and after treatment

The percentage of excellent Roles-Maudsley scores in the experimental group was significantly increased at 6 and 12 weeks after treatment compared with that before the operation, while the percentage of excellent grades in the control group was not significantly changed compared with that before the operation. There were significant differences in the Roles-Maudsley scores between the two groups at 6 and 12 weeks after treatment (p = 0.024, p = 0.025), indicating that there was a significant difference between the experimental group and the control group at 6 and 12 weeks after treatment. (See Table 3)

Table 3

Comparison of Roles-Maudsley scores during treatment between the two groups (n = 80)
		Control group (n = 40)	Test group (n = 40)	χ2	P
Pretreatment baseline	difference	85% (n = 34)	80% (n = 32)	0.346	0.770
	Fair	15% (n = 6)	20% (n = 8)
	Good	0 (n = 0)	0 (n = 0)
	Excellent	0 (n = 0)	0 (n = 0)
6 weeks after treatment	difference	5% (n = 2)	0 (n = 0)	8.140	0.024
	Fair	50% (n = 20)	30% (n = 12)
	Good	45% (n = 18)	62.5% (n = 25)
	Excellent	0 (n = 0)	7.5% (n = 3)
12 weeks after treatment	difference	10% (n = 4)	0 (n = 0)	8.498	0.025
	Fair	70% (n = 28)	60% (n = 24)
	Good	20% (n = 8)	32.5% (n = 13)
	Excellent	0 (n = 0)	7.5% (n = 3)

4.4 Main effect test of heel temperature (T1, T2, T3, T4, T5) levels in the two groups of patients

The heel temperature (T1, T2, T3, T4, T5) of the two groups of patients met the normal distribution and the homogeneity of variance (p > 0.05). After Mauchly's spherical hypothesis test, the variance covariance matrix of the dependent variables was not equal, so the results needed to be corrected by the Greenhouse‒Geisser method.

The results of heel temperature (T1, T2, T3, T4, T5) in the two groups showed that the time effect was statistically significant (F = 928.892, p < 0.001; F = 623.046, p < 0.001; F = 943.214, p < 0.001; F = 332.332, p < 0.001; F = 4470.958, p < 0.001), which reflected that the heel temperature (T1, T2, T3, T4, T5) levels of the two groups of patients changed with time during treatment. There were significant differences in the heel temperature (T1, T2, T3, T4, T5) between the two groups (F = 24.761, p < 0.001; F = 13.064, p = 0.001; F = 14.304, p < 0.001; F = 16.280, p < 0.001; F = 21.664, p < 0.001), which reflected the difference in heel temperature (T1, T2, T3, T4, T5) between the experimental group and the control group. There were significant differences in the interaction effect of heel temperature (T1, T2, T3, T4, T5) between the two groups (F = 158.98, p < 0.001;F = 69.790, p < 0.001; F = 106.332, p < 0.001; F = 345.050, p < 0.001). The influence of time factors on the heel temperature (T1, T2, T3, T4, T5) level varies with different treatment methods. Therefore, the individual effect should be used to test the time effect and intergroup effect of the two groups of patients. (See Table 4)

Independent effect test of the heel temperature (T1, T2, T3, T4, T5) levels before and after treatment in the two groups of patients.

Comparison within the group: The changes in heel temperature (T1, T2, T3, T4, T5) of PF patients in the experimental group and the control group at 6 weeks and 12 weeks after treatment were compared. The results showed that the plantar temperature (T1, T2, T3, T4, T5) decreased at 6 weeks and 12 weeks after treatment (p < 0.05).

Comparison between groups: The heel temperature (T1, T2, T3, T4, T5) levels of the experimental group at 6 and 12 weeks after treatment were lower than those of the control group (p < 0.05). (See Table 4)

Table 4

Comparison of the heel temperatures between the two groups (n = 80, mean ± SD)
Index	Peer group	Pretreatment baseline	Posttreatment		F,P(time)	F,P(between groups)	F,P(interaction)
Index	Peer group	Pretreatment baseline	6 week	12 week	F,P(time)	F,P(between groups)	F,P(interaction)
T1(℃)	Control group (n = 40)	28.37 ± 0.88	27.9 ± 0.89^*	28.08 ± 0.89^*#	F = 928.892, P < 0.001	F = 24.761, P < 0.001	F = 158.098, P < 0.001
	Test group (n = 40)	28.35 ± 0.97	27.33 ± 1.02^*&	27.44 ± 0.99^*#&
	t	0.101	2.658	3.037
	P	0.920	0.010	0.003
T2(℃)	Control group (n = 40)	27.99 ± 0.91	27.31 ± 0.91^*	27.58 ± 0.91^*#	F = 623.046, P < 0.001	F = 13.064, P = 0.001	F = 69.790, P < 0.001
	Test group (n = 40)	28.02 ± 0.87	26.79 ± 0.81^*&	27.01 ± 0.81^*#&
	t	-0.182	2.723	2.960
	P	0.856	0.008	0.004
T3(℃)	Control group (n = 40)	27.92 ± 0.88	27.12 ± 0.86^*	27.33 ± 0.88^*#	F = 943.214, P < 0.001	F = 14.304, P < 0.001	F = 80.134, P < 0.001
	Test group (n = 40)	27.96 ± 0.98	26.6 ± 0.96^*&	26.78 ± 0.90^*#&
	t	-0.207	2.533	2.776
	P	0.836	0.013	0.007
T4(℃)	Control group (n = 40)	28.03 ± 0.85	27.75 ± 0.79^*	27.86 ± 0.83^*#	F = 332.332, P < 0.001	F = 16.280, P < 0.001	F = 106.332, P < 0.001
	Test group (n = 40)	28.08 ± 0.93	27.24 ± 0.87^*&	27.33 ± 0.90^*#&
	t	-0.255	2.769	2.747
	P	0.800	0.007	0.007
T5(℃)	Control group (n = 40)	28.55 ± 0.88	27.84 ± 0.84^*	28.06 ± 0.87^*#	F = 4470.958, P < 0.001	F = 21.664, P < 0.001	F = 345.050, P < 0.001
	Test group (n = 40)	28.59 ± 0.91	27.31 ± 0.88^*&	27.33 ± 0.90^*#&
	t	-0.208	2.777	3.007
	P	0.836	0.007	0.007

* indicates p < 0.001 compared to pretreatment, # indicates p < 0.05 compared to 6 weeks posttreatment; & indicates p < 0.05 compared to the control group.

Comparison of the average pressure and maximum pressure level of the static plantar forefoot before and after treatment in the two groups of patients

After 6 weeks of treatment, the average pressure and maximum pressure of the static plantar forefoot of the affected side in the experimental group were significantly smaller than those before treatment, and the control group showed the same decreasing trend. After treatment, there was no significant difference in the average pressure and maximum pressure of the affected static plantar forefoot between the two groups before and after treatment (p = 0.669, p = 0.365). After treatment, the average pressure and maximum pressure of the static plantar hindfoot of the affected side in the experimental group were significantly higher than those before treatment, and the control group showed the same increasing trend. There was no significant difference in the average pressure or maximum pressure of the affected foot between the two groups before and after treatment (p = 0.490, p = 0.257). (See Table 5)

Comparison of the dynamic plantar medial and lateral load levels between the two groups before and after treatment

At 6 weeks after treatment, the dynamic medial plantar load of the affected side in the experimental group was significantly reduced compared with that before treatment, and the control group showed the same decreasing trend. There was no significant difference in the dynamic medial plantar load between the two groups before and after treatment (p = 0.995). After treatment, the dynamic lateral plantar load of the affected side increased significantly in the experimental group, and the control group showed the same increasing trend. There was no significant difference in the dynamic plantar lateral load between the two groups before and after treatment (p = 0.310). (See Table 5)

Table 5

Plantar pressure in both groups (n = 80, mean ± SD)
Index	Peer group	Pretreatment baseline	Posttreatment
Index	Peer group	Pretreatment baseline	6 week
Forefoot-Mean Static plantar Pressure(gr/cm²)	Control group(n = 40)	307.95 ± 58.06	285.18 ± 58.87
	Test group(n = 40)	311.23 ± 59.73	279.80 ± 53.18
	t	-0.249	-0.429
	P	0.804	0.669
hindfoot-Mean Static plantar Pressure(gr/cm²)	Control group(n = 40)	344.43 ± 51.53	372.93 ± 51.52
	Test group(n = 40)	347.50 ± 52.95	380.63 ± 47.80
	t	-0.263	-0.693
	P	0.793	0.490
Forefoot- Maximum Static plantar Pressure(gr/cm²)	Control group(n = 40)	594.85 ± 69.79	537.15 ± 86.77
	Test group(n = 40)	597.73 ± 70.09	520.05 ± 81.07
	t	-0.184	0.911
	P	0.855	0.365
hindfoot- Maximum Static plantar Pressure(gr/cm²)	Control group(n = 40)	605.73 ± 69.61	637.43 ± 82.00
	Test group(n = 40)	608.8 ± 70.32	657.85 ± 77.94
	t	-0.197	-1.142
	P	0.845	0.257
Dynamic medial load(%)	Control group(n = 40)	17.12 ± 4.69	16.08 ± 4.43
	Test group(n = 40)	17.33 ± 5.08	15.37 ± 4.40
	t	-0.191	-0.006
	P	0.849	0.995
Dynamic lateral load(%)	Control group(n = 40)	13.77 ± 3.73	15.08 ± 3.82
	Test group(n = 40)	13.78 ± 4.58	15.97 ± 3.99
	t	0.719	-1.022
	P	0.474	0.310

TrPs are considered excessive irritability points in skeletal muscle bandages. According to their relationship with symptoms, they may cause symptoms such as pain, muscle weakness, and reduced gange of motion (ROM)^[8]. Recent studies have shown that PF may be caused by trigger points caused by the myofascial membrane near the pain area, resulting in biomechanical imbalance of the entire limb and pelvis. The inactivation of trigger points may help relieve muscle tension and spasm, improve local circulation, and thus interrupt the vicious cycle of trigger points^[17]. Eliminating the active trigger points and hidden trigger points in the gastrocnemius muscle and soleus muscle can also effectively alleviate muscle fatigue and prevent the persistence of overload in the muscle. Therefore, myofascial injury in the lower limb area may affect the mechanical load of the foot and may play a role in the pathogenesis of plantar fasciitis. It has been confirmed in the literature that the treatment of trigger points can effectively improve the pain of plantar fasciitis^[18]. At present, the trigger point treatment for PF mainly includes dry needle therapy, injection drug therapy (anesthetics, steroids, botulinum toxin A) and extracorporeal shock wave therapy^[12]. As an alternative treatment, steroid injection has been shown to lead to plantar fascia rupture, fat pad atrophy, and even lateral plantar nerve injury^{[19, 20]}. In the past decade, ESWT has been increasingly used worldwide and is a relatively safe treatment. Several randomized controlled trials have studied the treatment of plantar fasciitis with extracorporeal shock waves at the medial heel pain point, confirming the effectiveness and safety of ESWT^[21]. At present, there are few studies on extracorporeal shock wave therapy combined with trigger points in the treatment of plantar fasciitis.

Temperature is one of the important parameters reflecting the physiological and pathological state of the human body. Different factors affect the epidermal temperature of the limbs and trunk. The epidermal temperature of the hands and feet is mainly dominated by vasoconstriction and dilatation^[22]. Chen et al.^[23] found that 3 to 24 months of chronic PF patients will have plantar fascia vascularization, resulting in changes in blood flow around the plantar fascia; in addition, the formation of new blood vessels around the plantar fascia often manifests as an increase in the skin temperature of the heel^[24]. Danielson et al. ^[25] found that the level of substance P (SP) in human serum around neovascularization was significantly increased in the patellar tendon of patients with patellar tendinitis, so it was speculated that SP was related to the formation of neovascularization. Carlsson et al.^[26] confirmed, through the study of animal models in rats, that the injection of SP into the diseased tissue of tendinitis would cause an increase in neovascularization in the tissue. These studies have shown that local temperature may indirectly reflect the level of pain-causing substances in the inflammatory area. Therefore, this study used plantar temperature measurement as an indirect indicator for efficacy evaluation. ESWT can inhibit the excitability of nerve terminal cells and reduce the release of SP substances^[27]. The expression of SP was inhibited, which blocked its effect on neovascularization, manifested as decreased blood flow in the heel and decreased heel temperature. The results of this study showed that the plantar temperature of the experimental group and the control group decreased at 6 and 12 weeks after treatment compared with that before treatment; the decrease in the experimental group was more significant; and the pain improvement was more obvious. However, the plantar temperature at 12 weeks after treatment was slightly higher than that at 6 weeks after treatment. At present, it is believed that the local temperature of the heel of PF patients may be repeated after extracorporeal shock wave treatment: (1) The treatment time of extracorporeal shock waves is relatively short and cannot completely eliminate the inducing factors of plantar fasciitis. The plantar fascia is still accompanied by vascular proliferation. When the treatment is over, it will cause the local temperature of the heel to rise. (2) After extracorporeal shock wave therapy, the degree of pain in PF patients is reduced, and the amount of activity tends to increase rapidly, resulting in excessive weight-bearing of the plantar and the re-emergence of SP in local tissues. At present, it is not clear whether the local temperature of the heel of PF patients can be used as an objective index to evaluate the degree of pain in patients with PF. Therefore, it is necessary to further explore the relationship between the two to provide a basis for the evaluation of plantar fasciitis by infrared thermal imaging.

Although gait analysis is considered an objective tool for assessing the progression of plantar fasciitis and the efficacy of treatment options^[28], few studies have reported the effect of extracorporeal shock waves combined with trigger points on gait in the treatment of plantar fasciitis. After treatment, the patient increased the load under the painful heel, indicating that the significant improvement of the heel landing stage and the plantar pain will cause the PF patient to change the original gait pattern, causing the heel load to decrease and the forefoot load to increase. One possible explanation for this finding is that there is inflammation in the calcaneus region in PF patients, which may increase the thickness of the plantar fascia, resulting in a decrease in the ability of the tissue to support the mechanical load in the heel region. The reduction of this ability to support load in the plantar fascia may lead to the use of analgesic measures to reduce the plantar load that is followed, resulting in an increase in the plantar load on the forefoot. The results are in line with those of SULLIVSN ^[16], and other studies have shown that PF patients often experience a decrease in the maximum pressure and peak pressure in the heel area. The lower the above value, the higher the pain degree of PF patients. This study shows that ESWT will change the local load of the affected foot, and the heel pain point combined with the trigger point ESWT treatment is more significant than the traditional simple heel pain point ESWT treatment on the plantar load change. These findings may be related to the recovery of the correct sliding of the fascia system, thereby addressing the biomechanical damage. Tension in the proximal muscles, such as contractures in the calf muscles, is likely to be transmitted to the distal muscles through the fascial chain. By solving the contracture of the proximal muscle tissue, the sliding of the entire 'calf fascia-Achilles tendon-plantar fascia' structure can be restored, which explains the improvement in foot pressure. However, further studies are needed to determine the relationship between gait improvement, plantar fascia healing and plantar fasciitis-related symptoms after ESWT. In conclusion, heel pain point combined with trigger point ESWT treatment not only reduces the degree of pain in PF patients but also improves gait parameters, which is helpful to restore more normal gait patterns in PF patients.

innovation and limitations

The main innovations of this study are as follows: 1. This study may provide a new idea for the treatment of PF patients: conventional extracorporeal shock wave combined with trigger point therapy provides a new direction for the treatment of PF; the heel temperature measured by infrared thermal imaging and the plantar data measured by plantar pressure plate provide objective measurement indicators for evaluating the efficacy of PF treatment. The results of this study confirm that extracorporeal shock wave therapy of heel pain points combined with triceps TrPs is a safe and effective conservative treatment for plantar fasciitis.

However, this study also contains at least several deficiencies: 1. Due to the treatment cycle, we only conducted follow-up after 12 weeks; the long-term clinical effect is not clear, and further follow-up is needed. 2. This study only designed a single treatment parameter but reviewed many published randomized controlled trials, and the results were different. Our results are only applicable to the treatment variables used in this study. Different treatment parameters of ESWT may have different effects on the treatment results. For plantar fasciitis, the optimal dose, parameters and course of treatment of ESWT need to be further explored in the future.

For refractory plantar fasciitis, ESWT treatment of the heel combined with the gastrocnemius and soleus trigger points can more effectively improve the pain, function and quality of life of patients than simple heel ESWT treatment. In addition, the ESWT of the heel combined with the triceps trigger point of the calf can effectively reduce the skin temperature of the heel on the symptomatic side, indicating that the heel temperature measured by infrared thermal imaging may be used as an independent tool to evaluate the therapeutic effect of patients with chronic plantar fasciitis. Although extracorporeal shock waves combined with TrPs treatment can cause changes in the gait structure of patients, plantar pressure is still difficult to use as an independent tool to evaluate the therapeutic effect of plantar fasciitis.

PF:Plantar fasciitis; ESWT :extracorporeal shock wave therapy; TrPs: trigger points; NRS:numerical rating scale; RMS:Roles and Maudsley score ; RCT:randomized controlled trial; BMI:Body Mass Index; IQR: interquartile range; ROM: gange of motion; SP: substance P.

Ethics approval and consent to participate

The study was conducted according to the principles of the Helsinki Declaration and approved by the Ethics Committee of Huadong Hospital Affiliated to Fudan University: No. 2021K109. This randomized controlled trial (RCT) has been registered at the Primary Registry of International Clinical Trial Registry Platform World Health Organization “Chinese Clinical Trial Registry” [ChiCTR2100054439].

Consent for publication

Not applicable.

Availability of data and materials

The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.

Competing interests

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Funding

This study was supported by the Science and Technology Commission of Shanghai Municipality (grant number 22Y11912600)、Key disciplines of Huadong Hospital Affiliated to Fudan University (grant number ZDXK2215)、Key Special Disease Project of Huadong Hospital Affiliated to Fudan University(grant number ZDZB2219).

Authors’ contributions

Conception and design: Bo Wang, Wei Wu, Yong-Jun Zheng;

Acquisition of data: Yan-Tao Ma Analysis and interpretation of the data: Xiao-Lei Wang;

Drafting of the article: Bo Wang, Xiao-Lei Wang;

Critical revision of the article for important intellectual content: Wei Wu. All authors contributed to and approved the final manuscript.

Acknowledgements

We thank LetPub (www.letpub.com) for its linguistic assistance during the preparation of this manuscript.

Hu Z C, Wu Y C, Xie Y Y. [Case of plantar fasciitis][J]. Zhongguo Zhen Jiu, 2013,33(10):924.
Ferreira G F, Sevilla D, Oliveira C N, et al. Comparison of the effect of hyaluronic acid injection versus extracorporeal shockwave therapy on chronic plantar fasciitis: Protocol for a randomized controlled trial[J]. PLoS One, 2021,16(6):e250768.
Trojian T, Tucker A K. Plantar Fasciitis[J]. Am Fam Physician, 2019,99(12):744-750.
Atzmon R, Eilig D, Dubin J, et al. Comparison of Platelet-Rich Plasma Treatment and Partial Plantar Fasciotomy Surgery in Patients with Chronic Plantar Fasciitis: A Randomized, Prospective Study[J]. J Clin Med, 2022,11(23).
Engkananuwat P, Kanlayanaphotporn R, Purepong N. Effectiveness of the Simultaneous Stretching of the Achilles Tendon and Plantar Fascia in Individuals With Plantar Fasciitis[J]. Foot Ankle Int, 2018,39(1):75-82.
Ibrahim M I, Donatelli R A, Schmitz C, et al. Chronic plantar fasciitis treated with two sessions of radial extracorporeal shock wave therapy[J]. Foot Ankle Int, 2010,31(5):391-397.
Ajimsha M S, Binsu D, Chithra S. Effectiveness of myofascial release in the management of plantar heel pain: a randomized controlled trial[J]. Foot (Edinb), 2014,24(2):66-71.
Ortega-Santiago R, Rios-Leon M, Martin-Casas P, et al. Active Muscle Trigger Points Are Associated with Pain and Related Disability in Patients with Plantar Heel Pain: A Case-Control Study[J]. Pain Med, 2020,21(5):1032-1038.
Thummar R C, Rajaseker S, Anumasa R. Association between trigger points in hamstring, posterior leg, foot muscles and plantar fasciopathy: A cross- sectional study[J]. J Bodyw Mov Ther, 2020,24(4):373-378.
Cotchett M P, Landorf K B, Munteanu S E. Effectiveness of dry needling and injections of myofascial trigger points associated with plantar heel pain: a systematic review[J]. J Foot Ankle Res, 2010,3:18.
Renan-Ordine R, Alburquerque-Sendin F, de Souza D P, et al. Effectiveness of myofascial trigger point manual therapy combined with a self-stretching protocol for the management of plantar heel pain: a randomized controlled trial[J]. J Orthop Sports Phys Ther, 2011,41(2):43-50.
Moghtaderi A, Khosrawi S, Dehghan F. Extracorporeal shock wave therapy of gastroc-soleus trigger points in patients with plantar fasciitis: A randomized, placebo-controlled trial[J]. Adv Biomed Res, 2014,3:99.
Tognolo L, Giordani F, Biz C, et al. Myofascial points treatment with focused extracorporeal shock wave therapy (f-ESWT) for plantar fasciitis: an open label randomized clinical trial[J]. Eur J Phys Rehabil Med, 2022,58(1):85-93.
Thompson J V, Saini S S, Reb C W, et al. Diagnosis and management of plantar fasciitis[J]. J Am Osteopath Assoc, 2014,114(12):900-906.
Cao L, Gao Y, Wu K, et al. Sympathetic hyperinnervation in myofascial trigger points[J]. Med Hypotheses, 2020,139:109633.
Ribeiro A P, Joao S M, Dinato R C, et al. Dynamic Patterns of Forces and Loading Rate in Runners with Unilateral Plantar Fasciitis: A Cross-Sectional Study[J]. PLoS One, 2015,10(9):e136971.
Ye L, Mei Q, Li M, et al. A comparative efficacy evaluation of ultrasound-guided pulsed radiofrequency treatment in the gastrocnemius in managing plantar heel pain: a randomized and controlled trial[J]. Pain Med, 2015,16(4):782-790.
Juchli L. Effectiveness of Massage Including Proximal Trigger Point Release for Plantar Fasciitis: a Case Report[J]. Int J Ther Massage Bodywork, 2021,14(2):22-29.
Acevedo J I, Beskin J L. Complications of plantar fascia rupture associated with corticosteroid injection[J]. Foot Ankle Int, 1998,19(2):91-97.
Sellman J R. Plantar fascia rupture associated with corticosteroid injection[J]. Foot Ankle Int, 1994,15(7):376-381.
Gerdesmeyer L, Frey C, Vester J, et al. Radial extracorporeal shock wave therapy is safe and effective in the treatment of chronic recalcitrant plantar fasciitis: results of a confirmatory randomized placebo-controlled multicenter study[J]. Am J Sports Med, 2008,36(11):2100-2109.
Hedrick M R. The plantar aponeurosis[J]. Foot Ankle Int, 1996,17(10):646-649.
Chen H, Ho H M, Ying M, et al. Association between plantar fascia vascularity and morphology and foot dysfunction in individuals with chronic plantar fasciitis[J]. J Orthop Sports Phys Ther, 2013,43(10):727-734.
Lemont H, Ammirati K M, Usen N. Plantar fasciitis: a degenerative process (fasciosis) without inflammation[J]. J Am Podiatr Med Assoc, 2003,93(3):234-237.
Danielson P, Alfredson H, Forsgren S. Distribution of general (PGP 9.5) and sensory (substance P/CGRP) innervations in the human patellar tendon[J]. Knee Surg Sports Traumatol Arthrosc, 2006,14(2):125-132.
Carlsson O, Schizas N, Li J, et al. Substance P injections enhance tissue proliferation and regulate sensory nerve ingrowth in rat tendon repair[J]. Scand J Med Sci Sports, 2011,21(4):562-569.
Notarnicola A, Moretti B. The biological effects of extracorporeal shock wave therapy (eswt) on tendon tissue[J]. Muscles Ligaments Tendons J, 2012,2(1):33-37.
Brachman A, Sobota G, Marszalek W, et al. Plantar pressure distribution and spatiotemporal gait parameters after the radial shock wave therapy in patients with chronic plantar fasciitis[J]. J Biomech, 2020,105:109773.

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Evaluation of the efficacy of trigger points combined with extracorporeal shock waves in the treatment of plantar fasciitis: heel temperature and plantar pressure

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