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Abstract

Background:

Medial tibial stress syndrome (MTSS) can impair training and daily activities, underscoring the need for effective treatment. However, there’s limited evidence on using lower-leg exercises for MTSS in recreational runners.

Purpose/Hypothesis:

The purpose of the present study was to determine whether adding lower-leg exercises to a multimodal therapeutic intervention improves the recovery from MTSS in recreational runners. It was hypothesized that adding lower-leg exercises to a multimodal therapeutic intervention would enhance its effect on foot posture and make MTSS recovery more effective than multimodal therapeutic interventions alone.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 40 recreational runners diagnosed with MTSS using history and physical examination (40% women; mean ± SD age, 23.9 ± 3.9 years) were then randomly divided into intervention (n = 20) and control (n = 20) groups. Both groups underwent a multimodal therapeutic intervention involving ice massage, foot orthoses, and extracorporeal shockwave therapy. The intervention group additionally received a tailored lower-leg exercise protocol involving stretching, strengthening, sensorimotor exercises, and foam roller myofascial release. Pain intensity, MTSS severity, perceived treatment effect, quality of life (QoL), and static and dynamic foot posture were assessed at baseline, 6-week, and 12-week follow-up evaluations.

Results:

A mixed model analysis of variance found no significant differences in pain intensity (P = .17) or MTSS severity (P = .30) between the intervention group and the control group. However, there were significant improvements in QoL (P = .003), static foot posture index (FPI) (P = .02), and dynamic arch index (DAI) (P < .001), for the intervention group. After 6 and 12 weeks, the intervention group displayed lower DAI scores than controls (P = .04 and P = .02, respectively). By week 12, the intervention group exhibited significantly higher QoL scores (P = .02) and lower FPI scores (P = .04) compared with controls.

Conclusion:

The study demonstrated that lower-leg exercises within a multimodal treatment positively affected foot posture and QoL, although they did not significantly alleviate pain or affect MTSS severity in recreational runners. Therefore, health care providers are encouraged to integrate these exercises into rehabilitation programs to improve foot posture and QoL for individuals with MTSS. However, future research should focus on larger sample sizes, objective measures, resting control groups, and longer follow-up periods to enhance the understanding of the effects of lower-leg exercises on MTSS management.

Registration:

IRCT 20170114031942N5 (Iranian Registry of Clinical Trials).

Keywords

running medical aspects of sports physical therapy/rehabilitation injury prevention lower-leg pain medial tibial stress syndrome

Medial tibial stress syndrome (MTSS) is a prevalent and debilitating overuse condition associated with jogging, running, and jumping activities.²⁴ MTSS refers to exercise-induced pain along the posteromedial border of the distal two-thirds of the tibia that occurs during activity and is provoked by palpation of the affected area, but it excludes pain from ischemic origin or signs of the stress fracture.⁴³ It accounts for up to 35% of all cases of exercise-induced leg pains²⁴ and involves approximately 10.7% of male and 16.8% of female recreational runners.⁶ Clearly, MTSS is problematic, as it can interrupt an individual’s active lifestyle and sports performance and potentially end sporting careers.^1,44 The long recovery time ranges from 4 to 18 months,^23,31 and there is a high recurrence rate, with individuals who have a history of MTSS experiencing a recurrence rate between 20.1 and 32.2 times greater than those without a history of the condition,^13,36 adding to the costs and inconvenience of MTSS. Therefore, there is an urgent need to reduce MTSS recurrence rates and prevent the development of MTSS in physically active individuals.

The treatment of MTSS includes various interventions such as avoiding the triggering activity, cross-training, cryotherapy, shockwave therapy, massage, and a pneumatic leg brace.^28,29,44 However, some systematic reviews have shown that these interventions are not effective in treating MTSS,^28,29,44 and most only address pain rather than the main causes of the condition. It is suggested that interventions targeting modifiable risk factors, such as normalizing lower-limb biomechanics, arch taping, foot orthoses, and ankle strengthening and stretching exercises, are more likely to be effective in treating MTSS.^1,15

Numerous risk factors have been proposed for MTSS, among which excessive foot pronation and reduced lower-leg girth are the most well-known and at the same time modifiable.^3,4,45 Both excessive foot pronation and reduced lower-leg girth can lead to MTSS symptoms by increasing tibiofascial traction and ground-reaction force on the tibia during running.^4,36,45,46 This is caused by the decreased damping capacity of the lower leg, impaired lower-leg muscle strength and endurance, and greater and longer eccentric activity of the antipronatory muscles.^4,36,45,46 Reduced plantarflexor muscle endurance capacity,^18-20 invertor and evertor strength imbalance,^20,47 smaller flexor hallucis longus cross-sectional area,¹⁹ and deficits in maximal plantarflexor isometric strength¹⁹ are other muscular risk factors associated with MTSS development. Burne et al⁴ found a causal relationship between reduced lean lower-leg girth and MTSS development in athletes, suggesting that the amount of lower-leg muscle bulk could affect the ability of the lower leg to attenuate ground-reaction forces, potentially leading to MTSS. In addition, Clement⁷ believes that calf muscle weakness and fatigue can predispose athletes to MTSS by transferring excessive force to the tibia. Wakeling et al⁴⁰ have reported that lower-leg muscle activity is responsive to ground-reaction forces, and this damping effect may play a role in injury prevention. Therefore, addressing well-known and modifiable risk factors such as foot pronation and lower-leg muscle dysfunction during treatment can be an effective therapeutic option to reduce the recurrence rates of MTSS and treat and/or prevent the condition.

Lower-leg exercises are often recommended for the treatment of MTSS,^21,41 and they are a key component of almost all interventions provided by studies for people with MTSS.^15,32 While it has not been scientifically proven yet, some studies suggest that lower-leg exercises may be effective in managing the pain and symptoms of individuals with MTSS.^21,23 Although lower-leg exercises have been shown to be effective in managing some overuse injuries related to excessively pronated feet^14,16 and resulted in a 2.42-fold lower rate of running injury compared with the control group in recreational runners,³⁸ no study has investigated the use of these exercises for runners with MTSS. Furthermore, a controlled trial found that adding arch support foot orthoses to a therapeutic intervention leads to an earlier diminishment of pain and MTSS severity and better perceived therapeutic effects.³⁰ However, this begs the question that if arch support foot orthoses can have such an effect by supporting the longitudinal foot arch, should it not be possible to address this directly through training of the ankle and foot muscles? Therefore, the purpose of the present study was to determine whether adding lower-leg exercises to a multimodal therapeutic intervention improves the recovery from MTSS in recreational runners. We hypothesized that adding lower-leg exercises to a multimodal therapeutic intervention would enhance its effect on foot posture and make MTSS recovery more effective than multimodal therapeutic interventions alone.

Methods

Study Design

This was a 12-week, parallel-group randomized controlled trial with repeated measures at baseline, 6-week, and 12-week follow-up (Figure 1).

Figure 1.

CONSORT (Consolidated Standards of Reporting Trials) flow diagram of participants’ enrollment, randomization, follow-up, and analysis.

Participants

Participants were recruited between June 2018 and August 2018 through presentations in local community, public, and university clubs in Isfahan, Iran. A group of 67 recreational runners with potential symptoms of MTSS were screened by a health care practitioner, and 40 individuals who met the inclusion criteria were included in the study. MTSS can be diagnosed accurately through patient history and physical examination.⁴² The inclusion criteria for the study required participants to have experienced exercise-induced pain that persisted for hours or days afterward, the pain located in the distal half of the posteromedial tibia over an area >5 cm in length (as pain <5 cm is typically associated with stress fractures).⁴⁶ Symptoms must have been present for ≥3 weeks, with discomfort specifically elicited upon palpation of the tibial posteromedial border, confirmed by a health care practitioner.^10,13,46 Confirmation of the diagnosis by a health care practitioner was also necessary. Additionally, participants had to be between 18 and 45 years old, regularly engage in recreational running for ≥45 minutes or >10 km per week over the past 3 months, and be capable of providing informed written consent.

Participants were not included in the study if they had a prior diagnosis of paresthesia, experienced other causes of exercise-induced leg pain (eg, tibial stress fracture and chronic compartment syndrome), were unhealthily obese (body mass index >35 kg/m²), had received physical therapy treatment in the previous 6 months, had a history of lower-limb traumatic injury or had undergone surgery within the past 6 months, or had a leg-length discrepancy of ≥2.5 cm.¹²

Ethical Approval

Participants were informed of the study procedures and provided written informed consent. All procedures were approved by the institution review board of Shahroud University of Medical Sciences, and the trial protocol was prospectively registered in the Iranian Registry of Clinical Trials.

Randomization

Participants were enrolled by an independent health care practitioner, and concealed allocation was conducted using a computer-generated sequence (Version 2.0; Random Allocation Software), created by an independent assessor who was not directly involved in the trial and did not participate in the analysis or interpretation of the results. A block randomization design (block sizes of 2, 4) was applied to ensure an equal number of male and female participants in each group. Patients were randomly assigned to either the intervention group or the control group using simple randomization with a 1:1 allocation ratio. Outcomes were assessed by a trained sports scientist (AH) who was blinded to the treatment allocation group. The group allocations were concealed from the investigators enrolling participants, laboratory specialists assessing the variables, and data analysts in sequentially numbered, opaque, sealed envelopes. The corresponding envelopes were opened after enrolled participants had completed all baseline assessments.

Outcome Measures

All assessments were carried out by a trained sports scientist who was blinded to group allocation (A.H.) and were performed 4 days before the first intervention session (baseline measurements), 6 weeks after intervention (follow-up 1), and 12 weeks after intervention (follow-up 2) for each group. All clinical assessments were conducted at a university-based laboratory.

Participants’ body mass was measured to the nearest 0.1 kg using a digital scale (SECA 760; Vogel & Halke GmbH & Co), and height was recorded with an accuracy of 0.1 cm. The body mass index was calculated by dividing body mass by the square of height (kg/m²). Data on the affected side, duration of symptoms in days, and weekly running distance in kilometers were also documented.

Pain severity was assessed using a linear visual analog scale, with pressure of 3 kg applied using an algometer (Baseline model 12-0304; Fabrication Enterprise Inc.) over the most tender area of the tibial border. The tenderest area of the leg (portion of 5-cm length ) was highlighted with a marker on each affected leg.³⁰

Perceived treatment effect was measured using the global rating of change on a 7-point Likert scale.³⁷ Patients were requested to assess their self-perceived “overall change” compared with their status at the initial visit. Response options were presented on a continuum, ranging from −3 (labeled "totally worse") on the left to +3 (labeled "totally better") on the right, with zero in the middle (labeled "no change"). A positive point to the right indicates improvement, while a negative point to the left indicates deterioration of the condition.

Quality of life (QoL) was measured using the paper format of the 36-item Short Form Health Survey (SF-36).²⁵ SF-36 consists of 36 items that are grouped into 8 domains and summarized in 2 summary subscales: the Physical Component Summary (PCS), composed of the physical functioning, role limitations due to physical health problems, bodily pain, and general health domains; and the Mental Component Summary (MCS), composed of the vitality, social functioning, role limitations due to mental health problems, and mental health domains. The SF-36 is scored from 0 to 100, with a higher score representing a better or more favorable QoL.

Dynamic foot posture was assessed using the dynamic arch index (DAI), measured with a pressure plate (50 × 60 cm, PT 3D Scan; Payafnavaran Ferdowsi Co) located at the center of a 12-m runway during self-selected walking speed trials. The DAI is calculated as the ratio of the midfoot contact area relative to the whole footprint area excluding the toes.⁸ A high ratio indicates higher foot pronation, with a ratio of <0.21 indicating a high arch, 0.21-0.28 indicating a normal arch, and >0.28 indicating a low arch.⁵

Static foot posture was assessed using the foot posture index (FPI)–6, which includes 6 specific criteria: palpation of the talar head, curvature above and below the lateral malleoli, calcaneal alignment in the frontal plane, prominence around the talonavicular joint, congruence of the medial longitudinal arch, and the degree of forefoot abduction or adduction relative to the rearfoot. Each criterion is rated on a scale from −2 to +2, and the total score defines the target foot posture as normal (0 to +5 score), pronated foot (+6 to +9 score), highly pronated foot (≥+10 score), supinated foot (−1 to −4 score), or highly supinated foot (−5 to −12).³⁵

Adverse events and adherence to the exercise program were recorded using a questionnaire completed by participants 4 times every 3 weeks. Adverse events were defined as short- to long-term consequences manifested in serious, distressing, uncomfortable, and unacceptable symptoms for the participants with a known or plausible association with treatment and those for which there is none.³³

Interventions

Extracorporeal shockwave therapy consisted of 5 sessions, beginning with 1500 pulses at an energy flux density of 0.1 mJ/mm² and incrementally increasing to 0.3 mJ/mm² by the final session. Participants were instructed to avoid intense exercise training for 48 hours following each shockwave therapy session. Additionally, they adhered to a graduated walk-to-run protocol designed to restore their functional level in accordance with operational requirements.

Multimodal Therapeutic Intervention

All participants, in both the control and the intervention groups, received a multimodal therapeutic intervention. This involved applying ice directly to the affected area for approximately 15 to 20 minutes after each running session.¹¹ Extracorporeal shockwave therapy was administered in 5 sessions, beginning with 1500 pulses at an energy flux density of 0.1 mJ/mm² and incrementally escalating to 0.3 mJ/mm² by the final session.^22,30 Participants were instructed to avoid intense exercise training for 48 hours following each shockwave therapy session. Additionally, they adhered to a graduated walk-to-run protocol designed to restore their functional level in accordance with operational requirements.^22,23 This protocol was based on the Wolff Law, emphasizing the need for appropriate stress to remodel bone and soft tissue, promoting optimal strength and tissue integrity.¹⁷ Preexisting foot orthoses were permitted, but participants were not allowed to modify them during the study period. At the beginning of the study, 25% of the participants in the intervention group and 30% of those in the control group were using foot orthoses, and they continued to use them throughout the study. Analgesic use was also recorded during baseline testing and at all follow-up visits. Participants were instructed to avoid cointerventions during the study period, starting 72 hours before participation in the study.

Participants in the intervention group received both the multimodal therapeutic intervention and the prescribed leg exercises concurrently right from the beginning of the treatment period.

Lower-Leg Exercise Intervention

Recreational runners in the intervention group received a lower-leg exercise intervention aimed to improve ankle flexibility, strength, and proprioception. The exercise program included 2 calf muscle stretching exercises (gastrocnemius and soleus), 3 strengthening exercises for the plantarflexors and invertor muscles, 1 sensorimotor exercise (the short-foot exercise) to enhance proprioception and intrinsic foot muscles, and 1 foam roller myofascial release technique to reduce calf muscle stiffness and improve ankle joint range of motion. Resistance exercises were performed using the participant’s body weight and TheraBand tubing. intensity of the strengthening exercises progressed throughout the study by increasing the load from yellow to red, green, blue, and finally black bands, as well as from 40% to 85% of one-repetition maximum (1RM) in free weights. The progression also included an increase in the number of sets (from 3 to 4) and repetitions (from 12 to 15) for isotonic strengthening exercises. For stretching exercises, the hold time increased from 20 to 30 seconds, and the repetitions rose from 5 to 7, provided the participants demonstrated good-quality movement. Once participants could complete 4 sets of 15 repetitions for 1 week without increasing symptoms, they advanced to the next color-coded levels of resistance with TheraBand (starting with yellow bands and moving sequentially to red, green, blue, and finally black bands, and from 40% to 85% 1RM of free weight). The intensity of the exercise program was prescribed on an individual basis and progressed from moderate (a score of 12-14) to high (a score of 14-16) using the rate of perceived exertion of the Borg scale²⁷ (Table 1).

Table 1

Lower-Leg Exercise Intervention Framework

Exercise	Description	Repetitions
Short foot sensorimotor exercise	The participants were able to elevate the medial longitudinal arch and bring the heads of the metatarsals to the heel without lifting the forefoot from the ground or flexing the toes. The exercise training began with a sitting position and gradually advanced to a double-leg stance position, before further progressing to a single-leg stance position.	Each repetition was held for 5 sec and repeated for up to 3 min (approximately 30 repetitions)
Foot invertor muscle strengthening	The participants were positioned on their side, with the foot being targeted placed on the lower side. They forcefully inverted their ankle and foot against the resistance provided by the elastic band.	Three sets of 12 to 15 repetitions
Plantarflexor muscle strengthening	The participants were seated and had an elastic band placed around the top of their both feet. They were instructed to forcefully plantarflex their entire foot toward the end of their ankle-foot range of motion.	Three sets of 12 to 15 repetitions
Toe curl exercise	The participants used their toes to pull a towel along a smooth surface. We achieved gradual resistance by placing 1- and 2-kg weights on the towel.	Three sets of 15 to 20 repetitions
Gastrocnemius muscle stretching	The participants stood in front of a wall, positioning their targeted foot further away from the wall. They then leaned forward while ensuring that their heel remained on the floor and their knee was fully extended.	Five repetitions of 20 to 30 sec
Soleus muscle stretching	The participants stood in front of a wall, positioning their targeted foot farther away from the wall. They then leaned forward while ensuring that the heel remained on the floor and the knee was flexed.	Five repetitions of 20 to 30 sec
Calf muscle release	The participants were seated with a foam roller placed underneath the midcalf. Then the opposite leg was crossed over the top of the other leg to increase pressure, while slowly rolling out the calf area.	Four repetitions of 45 sec with a 30-sec rest

The control group did not receive lower-leg exercises to uphold the integrity of the randomized controlled trial design, ensuring a clear baseline for assessing the specific effects of the exercise intervention and minimizing confounding variables. However, since all study participants experienced some degree of pain and disability, including a multimodal therapeutic intervention in both groups addressed ethical concerns regarding nontreatment and promoted robust results. Additionally, after completing the study, participants in the control group were given the opportunity to become familiar with the leg exercise intervention.

The interventions comprised clinic-based programs supervised by an experienced physical therapy and sports science specialist (M.F.M.), with input from a sports physician.

Statistical Analysis

Using the software package G*Power 3.1, we conducted a priori sample size calculations based on effect sizes of MTSS intensity from a previous study.³⁰ With an effect size of Cohen f = 0.25 (medium effect size), a 2-tailed significance level (α) of .05, and desired power (1-β) of 0.85, a sample size of 16 in each group was required. To account for an anticipated dropout rate of 20%, we enrolled 20 participants in each group.

SPSS statistical software (Version 18.0; SPSS Inc) was used for all statistical analyses. The normality of the data was assessed using the Shapiro-Wilk test. A 2 (groups: control/intervention) ×3 (times: baseline/6 weeks/12 weeks) mixed model analysis of variance was used to test the main and interaction effects of lower-leg exercise on the outcome measures (ie, pain intensity, MTSS severity, QoL, dynamic foot posture, and static foot posture). Additional follow-up comparisons were conducted using Bonferroni-corrected t tests for multiple comparisons. The values are presented as mean ± SD as well as the corresponding 95% CIs, and the statistical significance level was set at P < .05. To better understand the range of training gains, Cohen d_z was calculated, expressing the effect size of the comparisons. Values between 0.01 and 0.2, 0.21 and 0.50, 0.51 and 0.80, and over 0.81 represent trivial, small, medium, and large effects, respectively.

Results

Baseline characteristics are outlined in Table 2. No side effects were reported for the interventions.

Table 2

Participants’ Demographics and Clinical Characteristics^a

Variables	Intervention Group (n = 20)	Control Group (n = 20)	t	P
Sex, male/female	12/8	12/8	–	–
Age, y	23.5 ± 3.6	24.4 ± 4.1	0.9	.4
Mass, kg	78.5 ± 10.9	79.6 ± 8.1	0.4	.7
Height, cm	1.71 ± 0.06	1.73 ± .08	0.4	.7
Body mass index, kg/m²	26.7 ± 3.0	27.0 ± 3.4	0.3	.8
Affected side, left/right/bilateral	3/11/6	1/12/7	–	–
Target side, dom/nondom	15/5	15/5
Pain history, weeks	8.2 ± 1.7	8.8 ± 2.0	1.0	.3
No. of running sessions per week	3.85 ± 0.87	3.9 ± 0.97	0.2	.8
Minutes run per week	121 ± 18	124 ± 19	0.4	.7
Distance run per week, km	15.8 ± 3.0	14.7 ± 3.5	0.5	.6
Foot orthoses, yes/no	5/15	6/14
Analgesic using, yes/no
Baseline	12/8	16/4
Week 6	7/13	9/11
Week 12	4/16	3/17

Data are presented as mean ± SD or n. dom, dominant; nondom, nondominant. Dashes indicate not applicable.

There were no significant differences between groups in terms of pain intensity (F_{(1, 38)} = 1.8; P = .17) and MTSS severity (F_{(1, 38)} = 1.23; P = .30), indicating no significant difference between the intervention and the control groups (Table 3). However, a significant difference was found for QoL (F_{(1, 38)} = 6.25; P = .003), FPI (F_{(1, 38)} = 4.11; P = .02), and DAI (F_{(1, 38)} = 8.53; P < .001), indicating a significant difference between the intervention and control groups (Table 3). Follow-up comparison revealed that participants in the exercise group exhibited lower scores in DAI compared with the control group after 6 weeks of intervention (t₍₃₈₎ = 2.2; P = .04; Cohen d = 0.69 ) and 12 weeks of intervention (t₍₃₈₎ = 2.5; P = .02; Cohen d = 0.79) (Figure 2, A and B). In addition, a follow-up comparison showed that the QoL (t₍₃₈₎ = 2.6; P = .02; Cohen d = 0.43) and FPI (t₍₃₈₎ = 2.0; P = .04; Cohen d = 0.41) were significantly higher and lower for the intervention group than the control group at week 12, respectively (Figure 2, A and B). Regarding the physical and mental components of the QoL, there was a significant interaction for PCS scores (F_{(1, 38)} = 9.1; P = .001) but not for MCS scores (F_{(1, 38)} = 2.5; P = .07) (Table 3). Our data indicate that the perceived treatment effects improved over time for both the intervention and the control groups, with the intervention group showing more pronounced positive outcomes. By week 12, 55% of the intervention group reported feeling "totally better," compared with 40% in the control group. Additionally, at both week 6 and week 12, a higher percentage of participants in the intervention group reported "much better" or "totally better" improvements. However, chi-square analysis revealed no significant differences between the groups at the 6th and 12th weeks, with results showing χ² = 1.61 (P = .66) and χ² = 1.1 (P = .60), respectively (Figure 3).

Table 3

Descriptions of the Outcomes and Results of Mixed-Model ANOVA^a

Variables	Intervention	Control	Between-Group Difference, Mean (95% CI)	Group Effect		Time Effect		Group × Time Effect
	(n = 20)	(n = 20)		F	P	F	P	F	P
	Mean ± SD	Mean ± SD		F	P	F	P	F	P
Pain intensity (mm)
Baseline	59.5 ± 10.4	53.5 ± 10.9	6.0 (−0.8 to 12.8)	1.16	.29	306.3	<.001	1.8	.17
Week 6	35.8 ± 7.2	36.0 ± 9.4	−0.2 (−5.5 to 5.2)
Week 12	16.8 ± 9.9	14.9 ± 9.7	1.9 (−4.4 to 8.1)
MTSS severity (0 to 10)
Baseline	5.7 ± 1.2	5.9 ± 1.3	−0.2 (−1.0 to 0.6)	0.21	.65	193.7	<.001	1.23	.30
Week 6	4.0 ± 0.8	4.3 ± 1.0	−0.4 (−0.2 to 0.9)
Week 12	1.9 ± 1.5	2.1 ± 1.5	−0.3 (−0.7 to 1.3)
Quality of life (0 to 100)
Baseline	68.5 ± 5.5	70.5 ± 6.0	−1.5 (−5.2 to 2.2)	0.37	.55	206.9	<.001	6.25	.003
Week 6	79.3 ± 5.4	77.7 ± 7.9	1.5 (−2.8 to 5.9)
Week 12	86.6 ± 7.2	82.9 ± 9.8	3.8 (0.8 to 6.8)^b
Foot Posture Index (−12 to +12)
Baseline	6.0 ± 4.9	6.1 ± 4.9	−0.5 (−3.2 to 3.1)	0.16	.7	0.64	.53	4.11	.02
Week 6	5.6 ± 4.1	6.2 ± 4.9	−0.7 (−3.5 to 2.2)
Week 12	5.1 ± 3.6	6.8 ± 4.7	−1.79 (−3.7 to −0.12)^b
Dynamic arch index (score)
Baseline	27.2 ± 4.7	28.3 ± 4.4	−1.1 (−4.0 to 1.8)	17.75	<.001	9.17	<.001	8.53	<.001
Week 6	25.6 ± 4.1	28.3 ± 3.7	−2.7 (−5.2 to −0.21)^b
Week 12	25.0 ± 3.9	28.2 ± 4.2	−3.2 (−5.8 to −0.61)^b

ANOVA, analysis of variance; MTSS, medial tibial stress syndrome. Bold values refer to values that are significant at P < .05.

Significant between-group difference at P < .05.

Figure 2.

Standardized effect size related to between-group comparisons for each dependent variable (A) at week 6 and (B) at week 12. DAI, dynamic arch index; FPI, foot posture index; MTSS, medial tibial stress syndrome; PI, pain intensity; QoL, quality of life.

Figure 3.

Perceived treatment effect by participants of each group at the 6th and 12th weeks.

Discussion

The present study found no significant differences in pain levels, MTSS severity, or perceived therapeutic effects between the intervention and control groups among recreational runners with MTSS. However, the intervention group demonstrated significant improvements in the FPI, DAI, and QoL (PCS) compared with the control group. Specifically, the intervention group had lower DAI scores at 6 weeks (Cohen d = 0.69) and 12 weeks (Cohen d = 0.79). Additionally, at week 12, they exhibited higher QoL scores (Cohen d = 0.43) and lower FPI scores (Cohen d = 0.41), indicating meaningful benefits from the lower-leg exercises.

One of the findings from the present study was that incorporating lower-leg exercises in the multimodal therapeutic intervention resulted in an additional effect ranging from 10.5% to 12.8% on dynamic foot posture and 12% to 35% on static foot posture when comparing the intervention group with the control group during the follow-up period at the end of weeks 6 and 12. In line with our study, Mulligan and Cook²⁶ showed that engaging in foot muscle exercises for 8 weeks can decrease navicular drop by 2.2 mm and result in reduced excessive foot pronation by 29% in students with excessive foot pronation. Similarly, Andreasen et al² reported a reduction of 2 mm in navicular drops for patients with excessive pronation and chronic pain conditions. Electromyographic studies have demonstrated the critical role of both intrinsic and extrinsic foot muscles in maintaining the medial longitudinal arch and foot posture.^26,32,38 Muscle fatigue and weakness in these muscles have been identified as the causes of excessive foot pronation during running.^18,20 Therefore, engaging in lower-leg exercises can potentially enhance muscle endurance and strengthen the lower-leg muscles, leading to improvements in both dynamic and static foot posture. Considering that these exercises have the ability to affect static and dynamic foot posture in recreational runners with MTSS, serving as potential indicators of their effectiveness in preventing MTSS recurrence. The notion of MTSS potentially evolving into a tibial stress fracture suggests a continuum between the 2 conditions,⁴⁵ highlighting the need for further research to explore the long-term effectiveness of integrating lower-leg exercises in preventing MTSS recurrence and its progression to a full tibial stress fracture.

The present study revealed another significant finding regarding the effectiveness of lower-leg exercises when combined with other therapeutic interventions for individuals with MTSS. These additional exercises have been shown to enhance the overall QoL for these individuals, likely through their effects on the PCS rather than the MCS of the QoL. This observation suggests that the effects of therapeutic exercises on the QoL of individuals with musculoskeletal pain extend beyond just pain levels. Therefore, exercise therapy for individuals with MTSS may not directly reduce pain, but its multifaceted benefits, including enhancing lower-limb function, increasing muscle strength, improving psychological well-being, enhancing mobility, and preventing further exacerbation collectively contribute to an improved overall QoL.

An interesting finding from our study was that the addition of foot exercise to a multimodal therapeutic intervention did not have an additional effect on the management of pain level and MTSS-related symptoms, as confirmed by the perceived treatment effect. This result is consistent with a study by Andreasen et al,² who suggested that adding lower-leg exercises to other interventions resulted in a 2-mm decrease in navicular drop in patients with excessive pronation and chronic pain conditions, but did not have an incremental effect on reducing pain and symptoms in these patients. Moen et al²³ also compared 3 MTSS treatment methods (graded running protocol, graded running protocol with ankle exercises, and graded running protocol combined with a compression garment) and did not observe a significant difference in terms of the effect on the physical function and overall satisfaction with the treatment. Two theories have been proposed regarding the pathophysiology of MTSS: the tibial fascial–traction theory⁹ and the tibial stress reaction theory.¹⁹ According to the tibial fascia–traction theory, the eccentric contraction of the plantarflexor and invertor muscles of the lower leg, particularly the soleus, tibialis posterior, and flexor digitorum longus, during the stance phase of running, applies a strong traction force to the junction of these muscles. This force eventually leads to periostitis or fasciitis.⁹ Proponents of the tibial stress reaction theory believe that MTSS, similar to a tibial stress fracture, is a bone stress reaction resulting from repetitive loading and subsequent deformation of the tibial structure.⁴³ We hypothesized that by incorporating lower-leg exercises into a multimodal therapeutic intervention, we can enhance the damping capacity of the lower leg, strengthen the lower-leg muscles, increase endurance, and reduce compensatory contractions of the antipronatory muscles during the stance phase of running. This, in turn, would lead to a reduction in tibiofascial traction and the ground-reaction force applied to the tibia, potentially resulting in a faster or improved recovery from MTSS. However, the results did not align with our expectations, as the incorporation of lower-leg exercises into a multimodal therapeutic intervention had no incremental effect on pain levels and MTSS symptoms.

The intervention group participants experienced a decrease in tibial pain intensity of 2.4 cm at the end of the 6th week, which was higher compared with the control group that had a decrease of 1.8 cm in tibial pain intensity. Moreover, the decrease observed in the intervention group exceeded the minimal clinically important difference threshold of 2.2 cm for pain visual analog scale in orthopaedic studies.³⁴ However, the reduction in MTSS score was nearly the same in the control group (1.6) and the intervention group (1.7) in the 6th week. It is worth noting that any change exceeding 0.69 in the MTSS score is considered the smallest significant detectable change for patients with MTSS.⁴⁴ Additionally, based on the 7-point scale used, the mean perceived treatment effect by participants in the intervention group at the end of the 6th and 12th weeks was rated as "much better." However, for the control group, it was rated as "better" and "much better" at the respective time points. The trend of reducing analgesic use was almost the same for both groups, which is consistent with the observed trend in the variables of MTSS-related pain and symptoms. This suggests that the treatments effectively reduced analgesic dependence.

Strengths and Limitations

This study is the first to investigate the effects of lower-leg exercises on runners with MTSS, focusing on pain level, MTSS severity, QoL, foot posture, and perceived therapeutic effects. However, there are several limitations to consider. The small sample size, focused on recreational runners, may limit the generalizability of findings to other athlete populations. The study’s reliance on self-reported measures, such as pain and QoL, introduces potential biases that could be mitigated in future trials by incorporating objective methods such as bone scanning and kinematic analysis. While MTSS can be reliably diagnosed through patient history and physical examination,⁴² using imaging techniques could help rule out tibial stress fractures, particularly in cases of extensive pain. Although participants’ running volumes and terrains were not strictly controlled, both the intervention and the control groups reported similar running times, distances, and terrains at baseline, potentially minimizing injury-related differences. Participant blinding was not feasible due to the study’s nature and protocols, but implementing it would have ensured equal treatment and unbiased outcome assessment. Ethical concerns prevented the inclusion of a control group that solely rested, limiting the ability to draw definitive conclusions about the intervention’s effectiveness compared with rest. Moreover, the study did not analyze the participants’ energy availability, which may directly influence MTSS progression,⁶ or the type of footwear worn, which could affect biomechanics and injury risk.³⁹ The 12-week follow-up period may not adequately capture long-term outcomes, given that recovery from MTSS can extend up to 18 months. Future research should consider these factors to provide a more comprehensive understanding of their effects on MTSS management.

Conclusion

The high recurrence rate of MTSS, along with its enduring impact on physical and sometimes daily activities, underlines the need to explore the sustained effectiveness of incorporating to mitigate these consequences. The primary findings suggest that incorporating lower-leg exercises into a multimodal therapeutic intervention improved foot posture and QoL (physical aspects) but didn’t offer additional benefits in pain relief, MTSS severity, or perceived therapeutic effects in recreational runners with MTSS. Therefore, health care providers are encouraged to integrate these exercises into rehabilitation programs to improve foot posture and QoL for individuals with MTSS. However, future research should focus on larger sample sizes, objective measures, resting control groups, and longer follow-up periods to enhance the understanding of the effects of lower-leg exercises on MTSS management.

Footnotes

Final revision submitted August 6, 2024; accepted August 30, 2024.

The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Ethical approval for this study was obtained from Shahroud University of Medical Sciences (IR.SHMU.REC.1396.168).

ORCID iD

Aynollah Naderi

References

Alfayez

Ahmed

Alomar

AZ.

A review article of medial tibial stress syndrome. J Musculoskelet Surg Res. 2017;1(1):2-5.

Andreasen

Mølgaard

Christensen

, et al. Exercise therapy and custom-made insoles are effective in patients with excessive pronation and chronic foot pain—a randomized controlled trial. Foot. 2013;23(1):22-28.

Bennett

Reinking

Pluemer

Pentel

Seaton

Killian

Factors contributing to the development of medial tibial stress syndrome in high school runners. J Orthop Sports Phys Ther. 2001;31(9):504-510.

Burne

Khan

Boudville

, et al. Risk factors associated with exertional medial tibial pain: a 12 month prospective clinical study. Br J Sports Med. 2004;38(4):441-445.

Cavanagh

Rodgers

MM.

The arch index: a useful measure from footprints. J Biomech. 1987;20(5):547-551.

Clement

Taunton

Smart

McNicol

A survey of overuse running injuries. Phys Sportsmed. 1981;9(5):47-58.

Clement

DB.

Tibial stress syndrome in athletes. J Sports Med. 1974;2(2):81-85.

De Cock

Willems

Witvrouw

Vanrenterghem

De Clercq

. A functional foot type classification with cluster analysis based on plantar pressure distribution during jogging. Gait Posture. 2006;23(3):339-347.

Devas

. Stress fractures of the tibia in athletes or “shin soreness.” J Bone Joint Surg Br. 1958;40(2):227-239.

10.

Edwards

Wright

Hartman

JF.

A practical approach for the differential diagnosis of chronic leg pain in the athlete. Am J Sports Med. 2005;33(8):1241-1249.

11.

Galbraith

Lavallee

ME.

Medial tibial stress syndrome: conservative treatment options. Curr Rev Musculoskelet. 2009;2(3):127-133.

12.

Gross

RH.

Leg length discrepancy: how much is too much?

Orthopedics. 1978;1(4):307-310.

13.

Hubbard

Carpenter

Cordova

ML.

Contributing factors to medial tibial stress syndrome: a prospective investigation. Med Sci Sports Exerc. 2009;41(3):490-496.

14.

Huffer

Hing

Newton

Clair

Strength training for plantar fasciitis and the intrinsic foot musculature: a systematic review. Phys Ther Sport. 2017;24:44-52.

15.

Kuwabara

Dyrek

Olson

Kraus

Evidence-based management of medial tibial stress syndrome in runners. Curr Phys Med Rehabil Rep. 2021;9:177-185.

16.

Lee

Yoon

Cynn

Foot exercise and taping in patients with patellofemoral pain and pronated foot. J Bodyw Mov Ther. 2017;21(1):216-222.

17.

Levangie

Norkin

CC.

Joint Structure and Function: A Comprehensive Analysis. 5th ed. FA Davis Company; 2011.

18.

Madeley

Munteanu

Bonanno

DR.

Endurance of the ankle joint plantar flexor muscles in athletes with medial tibial stress syndrome: a case-control study. J Sci Med Sport 2007;10(6):356-362.

19.

Mattock

Steele

Mickle

KJ.

Lower leg muscle structure and function are altered in long-distance runners with medial tibial stress syndrome: a case control study. J Foot Ankle Res. 2021;14:1-8.

20.

Mattock

Steele

Mickle

KJ.

Are leg muscle, tendon and functional characteristics associated with medial tibial stress syndrome? A systematic review. Sports Med Open. 2021;7:1-14.

21.

Mendez-Rebolledo

Figueroa-Ureta

Moya-Mura

Guzmán-Muñoz

Ramirez-Campillo

Lloyd

. The protective effect of neuromuscular training on the medial tibial stress syndrome in youth female track-and-field athletes: a clinical trial and cohort study. J Sport Rehabil. 2021;30(7):1019-1027.

22.

Moen

Rayer

Schipper

, et al. Shockwave treatment for medial tibial stress syndrome in athletes; a prospective controlled study. Br J Sports Med. 2012;46(4):253-257.

23.

Moen

Holtslag

Bakker

, et al. The treatment of medial tibial stress syndrome in athletes; a randomized clinical trial. Sports Med Arthrosc Rehabil Ther Technol. 2012;4:12.

24.

Moen

Tol

Weir

Steunebrink

De Winter

TC.

Medial tibial stress syndrome. Sports Med. 2009;39(7):523-546.

25.

Montazeri

Goshtasebi

Vahdaninia

Gandek

The Short Form Health Survey (SF-36): translation and validation study of the Iranian version. Qual Life Res. 2005;14:875-882.

26.

Mulligan

Cook

PG.

Effect of plantar intrinsic muscle training on medial longitudinal arch morphology and dynamic function. Man Ther. 2013;18(5):425-430.

27.

Muyor

JM.

Exercise intensity and validity of the ratings of perceived exertion (Borg and OMNI scales) in an indoor cycling session. J Hum Kinet. 2013;39(1):93-101.

28.

Naderi

The effect of extracorporeal shock wave therapy on clinical and functional outcomes of individuals with medial tibial stress syndrome: a systematic review. J Military Med. 2022;23(12):989-998.

29.

Naderi

Bagheri

A review of the therapeutic and protective effects of kinesio taping and foot orthosis in patients with medial tibial stress syndrome. Sci J Rehabil Med. 2023;12(1):2-17.

30.

Naderi

Bagheri

Ramazanian Ahoor

Moen

Degens

Foot orthoses enhance the effectiveness of exercise, shockwave, and ice therapy in the management of medial tibial stress syndrome. Clin J Sport Med. 2022;32(3):e251-e260.

31.

Newman

Adams

Waddington

Two simple clinical tests for predicting onset of medial tibial stress syndrome: shin palpation test and shin oedema test. Br J Sports Med. 2012;46(12):861-864.

32.

Newsham

Boyd

Lauber

Intrinsic foot muscle training for medial tibial stress syndrome. Clin Pract Athl Train. 2023;6(1):1-12.

33.

Phillips

Hazell

Sauzet

Cornelius

Analysis and reporting of adverse events in randomised controlled trials: a review. Br J Sports Med Open. 2019;9(2):e024537.

34.

Randall

Zhang

Hubbard

Kazmers

NH.

Establishing the minimal clinically important difference and substantial clinical benefit for the pain visual analog scale in a postoperative hand surgery population. J Hand Surg Am. 2022;47(7):645-653.

35.

Redmond

Crane

Menz

HB.

Normative values for the foot posture index. J Foot Ankle Res. 2008;1(1):6.

36.

Reinking

Austin

Hayes

AM.

Risk factors for self-reported exercise-related leg pain in high school cross-country athletes. J Athl Train. 2010;45(1):51-57.

37.

Schmitt

Abbott

JH.

Patient global ratings of change did not adequately reflect change over time: a clinical cohort study. Phys Ther. 2014;94(4):534-542.

38.

Taddei

Matias

Duarte

Sacco

IC.

Foot core training to prevent running-related injuries: a survival analysis of a single-blind, randomized controlled trial. Am J Sports Med. 2020;48(14):3610-3619.

39.

Tenforde

Hoenig

Saxena

Hollander

Bone stress injuries in runners using carbon fiber plate footwear. Sports Med. 2023;53(8):1499-1505.

40.

Wakeling

Nigg

Rozitis

AI.

Muscle activity damps the soft tissue resonance that occurs in response to pulsed and continuous vibrations. J Appl Physiol. 2002;93(3):1093-1103.

41.

Winters

The diagnosis and management of medial tibial stress syndrome: an evidence update. Der Unfallchirurg. 2020;123(suppl 1):15-19.

42.

Winters

Bakker

Moen

Barten

Teeuwen

Weir

Medial tibial stress syndrome can be diagnosed reliably using history and physical examination. Br J Sports Med. 2018;52(19):1267-1272.

43.

Winters

Bon

Bijvoet

Bakker

Moen

MH.

Are ultrasonographic findings like periosteal and tendinous edema associated with medial tibial stress syndrome? A case-control study. J Sci Med Sport. 2017;20(2):128-133.

44.

Winters

Eskes

Weir

Moen

Backx

FJG

Bakker

EWP

. Treatment of medial tibial stress syndrome: a systematic review. Sports Med. 2013;43:1315-1333.

45.

Yagi

Muneta

Sekiya

Incidence and risk factors for medial tibial stress syndrome and tibial stress fracture in high school runners. Knee Surg Sports Traumatol Arthrosc. 2013;21:556-563.

46.

Yates

White

The incidence and risk factors in the development of medial tibial stress syndrome among naval recruits. Am J Sports Med. 2004;32(3):772-780.

47.

Yüksel

Ozgürbüz

Ergün

, et al. Inversion/eversion strength dysbalance in patients with medial tibial stress syndrome. J Sci Med Sport. 2011;10(4):737.

Effects of Integrating Lower-Leg Exercises Into a Multimodal Therapeutic Approach on Medial Tibial Stress Syndrome Management Among Recreational Runners: A Randomized Controlled Study

Abstract

Background:

Purpose/Hypothesis:

Study Design:

Methods:

Results:

Conclusion:

Registration:

Keywords

Methods

Study Design

Participants

Ethical Approval

Randomization

Outcome Measures

Interventions

Multimodal Therapeutic Intervention

Lower-Leg Exercise Intervention

Statistical Analysis

Results

Discussion

Strengths and Limitations

Conclusion

Footnotes

ORCID iD

References