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.

                   

Weeks to
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday

8

2286 #'Ö­

16

11

67

2743

2743/80/11

96/16

7

2286

21

Rest

67

2743

2743/67/16

96/8

6

2286

16

10

67

2743

2743/80/11

80/11

5

2286

26

Rest

67

2743

2743/96/8

67/11

4

2286

21

8

67

2743

2743/96/11

80/16

3

2286

16

8

67

2743

2743/72/16

64/8

2

2286

11

10

67

2743

2286/3.2

61/5

1

1829

8

Rest

40

Rest

64/1.6

Race day

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

Subject

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.

Interview Data

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.

Physical Examination

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.

Outcome Measures

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.

Treatment

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.

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