Defective Running Shoes as a Contributing Factor in Plantar Fasciitis in a Triathlete
Bruce R. Wilk, PT, OCS1
Karen L. Fisher, MS, PT2
William Gutierrez, MS, PT, OCS, ATC3
Study Design: Case study of a patient who developed plantar fasciitis after completing a triathlon.
Objectives: To describe the factors contributing to the injury, describe the rehabilitation process, including the analysis of defective athletic shoe construction, and report the clinical outcome.
Background: Plantar fasciitis has been found to be a common overuse injury in runners. Studies that describe causative factors of this syndrome have not documented the possible influence of faulty athletic shoe construction on the symptoms of plantar fasciitis.
Methods and Measures: The patient was a 40-year-old male triathlete who was followed up for an initial evaluation and at weekly intervals up to discharge 4 weeks after injury and at 1 month following discharge. Perceived heel pain, ankle strength, and range of motion were the primary outcome measures. Shoe construction was evaluated to assess the integrity of shoe manufacture and wear of materials by visual inspection of how shoe parts were glued together, if shoe parts were assembled with proper relationship to each other, if the shoe sole was level when resting on a level surface, and if the sole allowed unstable motion.
Results: The patient appeared to have a classic case of plantar fasciitis with a primary symptom of heel pain at the calcaneal origin of the plantar fascia. On initial evaluation, right heel pain was a 9 of 10, plantar flexion strength was a 3 +15, and ankle dorsiflexion motion was 10°. One month after discharge, perceived heel pain was 0, plantar flexion strength was 5/5, and dorsiflexion motion was 15° and equal to the uninvolved extremity. The right running shoe construction deficit was a heel counter that was glued into the shoe at an inward leaning angle, resulting in a greater medial tilt of the heel counter compared with the left shoe. The patient was taught how to examine the integrity of shoe manufacture and purchased a new pair of sound running shoes.
Conclusions: A running shoe manufacturing defect was found that possibly contributed to the development of plantar fasciitis. Assessing athletic shoe construction may prevent lower extremity overuse injuries. I Orthop Sports Phys Ther 2000;30:21—31.
Key Words: defective athletic footwear, plantar ligament inflammatory syndrome, running
Physical therapists frequently treat patients with injuries sustained from running. Often these pathologic conditions stem from poor skeletal alignment in the pelvis and lower extremity. According to Gross1° and others, musculoskeletal pathologic conditions may be exacerbated by pelvic and lower limb malalignments or biomechanical imbalances caused by training techniques, footwear, running style, environmental terrain, and sport-specific athletic conditioning. Physical therapists routinely inspect shoes and wear patterns in patients who develop pelvic and lower limb musculoskeletal pathologic conditions. In our clinic, examination of athletic shoe construction (in patients with common lower extremity overuse
injuries) has revealed manufacturing defects in shoes that were used at the time of injury. Although the cause of an overuse injury is multifactorial, a review of the literature did not reveal any studies of defective athletic shoe construction as a contributing source of common lower extremity overuse injuries.
This case report is based on the clinical observation of a patient who developed plantar fascitis while wearing a pair of running
TABLE 1. The patient’s training schedule 8 weeks before the race.
shoes that were found to have a manufacturing defect. The study identifies the musculoskeletal pathologic structure and looks at the possible factors that contributed to this injury. The patient’s specific treatment plan is described, and the patient’s response to the treatment is delineated. Suggestions are made for patient education in proper shoe selection and foot support. Clinical guidelines were created and are presented to teach patients how to assess the quality of athletic shoe construction.
METHODS AND MEASURES
A 40-year-old male triathiete with a diagnosis of plantar fasciitis was referred to physical therapy by his family physician. The patient complained of the onset of heel pain in his right foot after completing a haif-ironman triathion, which consists of a 2-km swim, a 90-km bike ride, and a 21-km run. The patient was an experienced triathiete, and he described a well-rounded training program. His regimen included a daily flexibility routine and a biweekly strength training routine. Biking and running workouts were performed over bridges to simulate hill training, because the patient lived in a flat environment and the race course was hilly.
The patient was familiar with the race course, because he had trained and competed on it previously. Table 1 shows the patient’s training schedule 8 weeks before the race. The patient used the same brand and model of running shoes for more than 2 years, with replacement of worn shoes every 480—800 km. The patient felt the weather conditions during the race were favorable, since it had been cool and overcast, even though it rained for a short period at the beginning of the run. Several hours after the race, the patient noticed a gradual onset of right inferomedial heel pain, which presented as a dull, constant ache. The day after the race, the patient noticed sharper pain in the same location on the right foot,
especially when taking the first several steps in the morning. These symptoms were severe enough to cause the patient to limp while walking and made it impossible to run. There was no history of heel pain. Rest from weight-bearing activities and icing helped to alleviate the pain. The patient also noted that initially he had minor muscle soreness in the right proximal calf.
Two days after the race, the patient was seen for an initial physical therapy evaluation. One clinician completed the patient examination. The right lower extremity plantar fascia and soft tissues were examined with palm and fingertip palpation. Varying pressures from light touch to deep pressure were used to determine the irritability of the plantar fascia and associated tissues and the patient’s perceived pain. With the toes maintained in passive extension, firm palpation pressure was exerted on the medial border of the plantar fascia along the longitudinal arch. This palpation procedure was repeated with the patient actively dorsiflexing the right ankle and extending the great toe.
The patient’s lower extremity alignment was evaluated by measuring the subtalar joint angle in standing, using a goniometer. The therapist measured the angle created by a line bisecting the posterior aspect of the distal third of the lower leg and a line bisecting the posterior aspect of the rear foot)° There were 5° of calcaneal eversion bilaterally.
Further musculoskeletal evaluation of the right lower extremity included gait analysis, manual muscle testing, and flexibility testing of the gastrocnemius muscle. The patient’s gait was visually examined, with the patient walking at a moderate pace within his pain tolerance. Gait deviations were compared with the conventional components of a normal gait cycle. Manual muscle testing was completed using the traditional manual muscle testing positions and scale, according to Daniels and Worthingham’s manual muscle testing text.’4 Gastrocnemius muscle flexibility testing was completed by measuring the angle of ankle dorsiflexion with a goniometer, while passively
FIGURE 1. Sections and components of a running shoe.
dorsiflexing the non—weight-bearing ankle from a subtalar neutral position with the knee in 0° extension. The end feel of the dorsiflexion range of motion was noted. An x-ray report revealed no evidence of anatomic abnormalities, stress fractures, bony tumors, osteophytes, or degenerative joint disease.
Shoe evaluation involved visual inspection of shoe parts as shown in Figure 1. The shoe was assessed for the integrity of construction and the wear of the shoe materials.
The patient’s heel pain and deficits were found exclusively on the right lower extremity. The patient appeared to have a classic case of plantar fasciitis, with a primary symptom of heel pain at the calcaneal origin of the plantar fascia.
The patient perceived his right heel pain as intense by rating the pain as a 9 on a subjective 0 to 10 visual analog scale (where 0 indicates the absence of pain and 10 indicates the maximum pain). Moderate pressure fingertip palpation over the right inferomedial calcaneus elicited a verbal pain response and limb withdrawal due to pain. With the toes maintained in extension passively, firm pressure to the medial border of the plantar fascia elicited the previous pain response. In bare feet, the patient’s standing posture revealed ankle pronation on both lower extremities. Using a goniometer, 5° of calcaneal eversion were measured during static single-limb support on each lower extremity.
Musculoskeletal evaluation of the right lower extremity revealed the following. First, the patient displayed an antalgic gait pattern, where the transfer of body weight was executed with a nearly flat foot, resulting in a shortened stance of the right lower extremity due to decreased heel strike and push-off phases. Second, manual muscle testing produced heel pain and showed impaired gastrocnemius and
FIGURE 2. In this posterior view, gray arrows (A and B) point to the mild inward lean of the training (T) shoe heel counters. The upper, outside borders of the heel counters show an inward bending of the lateral portion of the heel counter due to the stress from the repetitive pronation force during running.
soleus strength; the patient was able to complete 5 repetitions of full-range heel raises, representing strength in the 3+/5 range on the standard manual muscle testing scale.14 Third, a limitation in the passive (non—weight-bearing) dorsiflexion of the ankle from a subtalar neutral position (with 0° knee extension) revealed a decreased flexibility of the gastrocnemius muscle; right ankle dorsiflexion measured 10° compared with 15° on the left ankle; there was a firm end feel to the motion, and the patient reported feeling a pulling sensation in the right calf.
The stabilizing components of the patient’s training and racing shoes included a visible rear foot grid system with heel counter reinforcement and a compression-molded midsole of ethylene-vinyl acetate foam and dual-density polyurethane. Both pairs of shoes showed posterolateral heel wear. Each of the training shoes showed a mild inward lean of the heel counter (Figure 2). According to the patient, the training shoes had approximately 480 km of wear, and the racing shoes had approximately 48 km of wear. Examination of the racing shoes revealed the right shoe heel counter had a visibly larger inward tilt compared with the left racing shoe (Figure 3) and the training shoes (Figure 2). The right racing shoe heel counter was glued into the shoe at an angle that we thought could have caused excessive inward rolling of the right foot.
The goals of treatment for plantar fasciitis were to decrease inflammation; increase flexibility and strength; improve functional agility, running skills, and conditioning; return gradually to a training schedule; and educate the patient about the components of sound athletic shoe construction.