An osteopathic assessment of lower extremity somatic dysfunctions in runners

Methods

This study was reviewed and approved by the Touro College of Osteopathic Medicine Institutional Review Board (IRB #HSIRB_2018). The study was submitted to the Clinical Trial Registry (#NCT05132894) before subject accrual. The study was awarded the Touro Student Research Fellowship grant, which supported materials fees for the study. Participants were not rewarded for participating in the study.

The subjects included Touro students and individuals in the community. Subjects were recruited via verbal contact and social media marketing. Due to COVID-19 and limitations with in-person assessments, data collection took place over approximately a 4-month period (November 2021 to February 2022) followed by data analysis. Every subject signed a written electronic consent, which was collected by one of the team members.

A survey was developed by the research team to collect a history of the individual’s running habits (including but not limited to shoe brand, running surface, cross-training activities, and distance), chronic/acute injuries, and any other relevant medical information (Supplementary Material). The survey was created based on a review of several physical therapy questionnaires that also seek to gather a holistic view of the runner and their history of injuries. The survey was anonymous and administered via a tablet at the time of OMM physical assessment. All 103 participants completed it, but this survey was not linked to physical assessments.

Following the survey, an osteopathic assessment (Supplementary Material) was conducted and supervised by an osteopathic physician and/or a second student for validity purposes. The examinations lasted less than 10 min each. There was no risk of any kind in participation in this study. Participation in the study was strictly voluntary.

After completion of both the survey and the clinical assessment, discrete quantitative statistical analyses were performed. The main objective was to perform correlation studies to identify dependence of variables with significance mainly with the clinical assessment. Subjective analysis of the survey was employed to gain a better understanding and context of the population examined.

Results

Discussion

Pes planus, commonly known as flat-footedness or low arches, is the loss of the medial longitudinal arch of the foot, resulting in a majority of the foot making contact with the ground. Dysfunction of the arch complex can alter the biomechanics of the lumbar spine and lower extremity, causing an increased risk of pain and injury. Pes planus can be either congenital or acquired.

Anatomically, the posterior tibial tendon supports the arch and plantar flexion of the foot, so pes planus is often the result of posterior tibial tendon dysfunction (Figure 1). In the expanded research phase with 103 participants, 63.1 % of participants demonstrated unilateral or bilateral pes planus, which exceeds the national average of pes planus, which is estimated to be 20–37 % [3]. In runners, the lack of an arch can especially strain lower extremity muscles and puts the runner at an increased risk of injury [4].

Figure 1:

Weight-bearing lateral X-ray showing the measurement of calcaneal pitch, which is an angle of the calcaneus and the inferior aspect of the foot, with different sources giving different reference points. A calcaneal pitch of less than 17° or 18° indicates flat feet. Image by Mikael Häggström, MD. Public domain (CC0 1.0).

Limb length discrepancy of the lower extremity, also known as limb length discrepancy, is a difference in the length of an individual’s legs. This can be congenital in nature or a result of illness or injury to the lower extremity that causes the discrepancy over time.

Anatomically, the femur and/or the tibia is shorter than the other due to fracture, infection, congenital malformation, idiopathic, or of another known cause. However, if the cause is functional, the length of the bones is the same but appears unequal due to pelvic misalignment or muscle imbalances that strengthen one side of the spine, hip, and pelvis more than the other (Figure 2).

Figure 2:

The image depicts postural compensation for limb length discrepancy. While the spine may compensate over time, the effect of the pelvic side shift and leg rotation can cause more immediate muscle spasm and hypertonicity. Image by LuluCustom, https://dr-abbie.com/factsheets/short-leg-syndrome.

This discrepancy may affect upwards of 75 % of the population, thus causing an increased risk of lower back, pelvis, and leg pain. In the analysis, 65.0 % of our participants demonstrated a limb length discrepancy upon assessment [5].

Based on the statistics and qualitative data above, it can be concluded that the etiology of acute/chronic pain and injuries to the lower extremity are commonly multifaceted and compensatory in nature due to the foundational osteopathic principle that structure and function are reciprocally interrelated. Additionally, from the survey, the study gleaned that despite these injuries, individuals continue to run but do not necessarily apply the benefits of certain extrinsic factors that have the potential to reduce pain and minimize the risk of overuse or compensatory injury.

For individuals with pes planus, it can cause your leg to roll inward or internally rotate, forcing the piriformis muscle to become hypertonic and poorly function, causing your hip to roll inward, thus hurting your knees and feet and affecting your quadriceps and hamstrings. Through overuse, the strain on your feet can cause your lower extremity muscles to spasm. A change in the normal posture and positioning of the foot may be the result of somatic dysfunction within the structure of the foot itself, or due to injury or instability of the foot’s stabilizing ligaments. These adjustments may have a profound effect on the patient’s posture and gait, and may result in compensatory somatic dysfunction elsewhere, such as in the lower extremities or in the pelvis or lumbar region [6].

According to the data presented, this theory supporting pes planus may influence the hypertonicity seen in the major muscle groups of the lower extremity. Of note, since the body is a system of complex interconnected structures and functions, the cause of flat feet and hypertonicity could go either way or be cyclical in nature.

For these individuals, it is especially important that they obtain a shoe fitting, a gait analysis, and custom arch support to provide the necessary structure to their foot to reduce pain and compensatory spasm or injury to lower-extremity musculature and joints. Additional cross training to stretch muscles and strengthen hips to reduce internal knee rotation and foot overpronation can benefit the runner.

For runners with limb length discrepancy, it could be minimal and asymptomatic or feel like one foot strikes the pavement harder than the other, or the runner simply feels or looks lopsided in their posture. This difference can cause an imbalance in the center of gravity and pain in the lower extremity as muscles and joints will unilaterally take on more stress and cause a compensatory reaction.

According to the data presented, there is a possibility that muscle hypertonicity of the piriformis, quadriceps, and hamstrings with lower extremity pain could partially be attributed to limb length discrepancy.

For individuals with symptoms such as unilateral hip or back pain, they should be evaluated for structural or functional etiology. If the former, a shoe lift can be placed to resolve the unequal limbs. If the latter, the leg responds well to biomechanical orthotic therapy, pelvic realignment, and stretching of the hamstrings and hip rotators [5].

In both cases, the runner will benefit from regular stretching, cross-training, intermittent rest and rehabilitation, and good nutrition and hydration habits. Furthermore, all runners could benefit from osteopathic manipulative treatment (OMT) for assessment and management of somatic dysfunctions to not only resolve injury but also reduce risk of future injury and compensatory injury.

Limitations of this study include a limited sample size partially due to the pandemic and safe access to subjects. Additionally, the data are mainly qualitative in nature, so further research could focus in on specific somatic dysfunctions and apply quantitative measurements (ie, Measurement of the Meary’s Angle for pes planus) [3]. The study would also benefit from a control group to assess somatic dysfunctions in nonrunners. Further study and participation expansion is indicated to confirm qualitative associations in a quantitative manner. With quantitative results, more thorough intervention recommendations, such as arch supports and shoe lifts, could be provided.

Proper management of these extrinsic factors and treatment for common somatic dysfunctions can help to minimize, overcome, and prevent pain and injury in runners.

Conclusions

Runners’ pains and injuries of the lower extremity are complex, and injury treatment and prevention is equally multifaceted. The purpose of this study was to assess these extrinsic factors and common somatic dysfunctions, and we concluded that many runners continue to run in pain and/or after significant injury but do not necessarily capitalize on existing support.

Through an osteopathic assessment, there is an association between both pes planus and limb length discrepancy with lower extremity muscle hypertonicity, suggesting the interrelated nature of these somatic dysfunctions. The survey concluded that many runners continue to run in pain and/or after significant injury but do not necessarily capitalize on existing support such as fitted shoes, custom arches, and osteopathic treatment that may help to minimize their risk of injury or to treat their injury. Under the osteopathic precept that structure and function are interrelated, our intention is that this research will bring awareness to practitioners to the most common somatic dysfunctions such that they can recommend runners to obtain gait analyses and/or osteopathic treatment, which may not only alleviate injuries faster but also prevent future injury.