Medial tibial stress syndrome (tibial fasciitis): a proposed pathomechanical model involving fascial traction.

Although medial tibial stress syndrome is one of the most common lower-extremity overuse injuries, its pathomechanics remain controversial. Two popular theories have been proposed to account for this condition: tibial bending and fascial traction. This article evaluates the role of fascial traction in medial tibial stress pathomechanics. We hypothesized that with contraction of the deep leg flexors tension would be imparted to the tibial fascial attachment at the medial tibial crest. We also speculated that circumferential straps would dampen tension directed to the medial tibial crest. The amount of strain present in the tibial fascia adjacent to its distal medial tibial crest insertion during loading of the leg was investigated as a descriptive laboratory pilot study using three fresh cadaver specimens. Strain in the distal tibial fascia was measured using strain gauges placed in the fascia at its medial tibial crest insertion. As tension on the posterior tibial, flexor digitorum longus, and soleus tendons increased, strain in the tibial fascia increased in a consistent linear manner (P < .0001). We conclude that fascial tension may play a role in the pathomechanics of medial tibial stress syndrome. The tenting effect of the posterior tibial, flexor digitorum longus, and soleus tendons caused by muscle contraction exerts a force on the distal tibial fascia that is directed to its tibial crest insertion. Circumferential straps provided no dampening effect on tension directed to the medial tibial crest.

Competencies as an evaluation tool.

Competency-based resident education focuses on resident performance (learning outcomes) in reaching specific competencies (goals and objectives of the curriculum). The seven competencies that are outlined in the Council on Podiatric Medical Education 320 document are organizing principles for a podiatric residency curriculum. Through the use of the competencies, the resident evaluation can be constructed to best determine the need for resident intervention as well as program improvements.

Biomechanics of the first ray part V: The effect of equinus deformity. A 3-dimensional kinematic study on a cadaver model.

The positional change of the medial column of the foot in closed kinetic chain with variable Achilles tendon tension was investigated in seven fresh frozen cadaver specimens using a 3-dimensional radio wave tracking system. The distal tibia and fibula and the intact ankle and foot and were mounted on a non-metallic loading frame. The frame allowed positioning of the foot to simulate midstance phase of gait while the tibia and fibula were axially loaded to 400 N. To record osseous motion, receiving transducers were attached to the first metatarsal, medial cuneiform, navicular, and talus. Movements of these bones in 3-dimensional space were measured as specimens were axially loaded and midstance motor function was simulated using pneumatic actuators. To simulate a progressive equinus influence, force was applied to the Achilles tendon at tensile loads of 0%, 30%, and 60% of predicted maximum strength during each test trial. Osseous positions and orientations were collected and analyzed in all three cardinal planes utilizing data recorded. As Achilles load increased, the position of the first metatarsal became significantly more inverted ( P < .05). Although not statistically significant, remarkable trends of arch flattening motion were detected in the distal segments of the medial column with varied Achilles load. Increased Achilles load reduced the influence of peroneus longus on the medial column.

Biomechanics of the first ray. Part IV: the effect of selected medial column arthrodeses. A three-dimensional kinematic analysis in a cadaver model.

This study is the fourth in a series of investigations on the biomechanics of the first ray, this part focusing on open kinetic chain range of motion simulating the clinical examination. Segmental sagittal range of motion of the medial column was measured on intact cadaver specimens and compared to various simulated medial column arthrodesis patterns. These arthrodeses included the first metatarsocuneiform, first metatarsocuneiform-intercuneiform, naviculocuneiform, and talonavicular joints. The specimens were mounted to a test apparatus that was comprised of a modified ankle-foot orthosis which held the ankle and rearfoot in fixed neutral position. Additionally, the lesser metatarsus was affixed to the test apparatus while the first ray was left free to be manipulated via a carbon fiber rod attached to a pneumatic actuator. A 24.5-N (5.5-lb) sagittal plane load was applied to the first ray while the specimen was held rigidly in the apparatus. The first ray was manipulated using a repeated measures design. Data were collected for each osseous segment of the medial column using a radiowave tracking system. Kinematic data were collected and statistically analyzed. Results demonstrated in intact specimens that the naviculocuneiform, first metatarsocuneiform, and talonavicular joints contributed an average of 50%, 41%, and 9% of total first ray sagittal plane range of motion, respectively. Furthermore, first ray range of motion was significantly reduced with all of the simulated arthrodeses of the medial column (p < .05). These findings suggest that first ray range of motion when evaluated clinically is a blend of motions of joints comprising the medial column.