The purpose of this study was to compare the effect of knee position on the magnitude of torque generated during the isokinetic movements of inversion and eversion at the ankle. Mean peak torque values at 30 and 120°/sec were collected from 12 subjects, ages 21-31, from two test positions. The knee was stabilized in 10° of flexion for the first test position and 70° for the second. Additionally, mean peak amplitude of hamstring motor unit action potentials was compared between the two test positions to demonstrate differences in hamstring activity. At both speeds, mean peak torque values of the inversion-eversion movements, as well as mean peak amplitude of hamstring motor unit action potentials, was significantly lower in 10° compared to 70° of knee flexion (p < 0.01). It was concluded that isokinetic testing at the ankle with the knee in a close packed position, near full extension, provides a more valid representation of isolated muscular performance than testing with the knee in a loose packed position of midrange flexion.

J Orthop Sports Phys Ther 1988;10(5):177-183.

J Orthop Sports Phys Ther 1989;11(4):150-154.

The purpose of this investigation was to document the degree of weakness present in the medial and lateral muscle groups of individuals with chronically unstable ankles. Peak isometric and isokinetic torque measurements were collected bilaterally during the motion of inversion-eversion from 33 subjects, ages 17 to 54, reporting unilateral chronic lateral instability. Values were then compared between the involved and uninvolved sides. A modified Romberg test was also performed bilaterally to determine gross balance differences between the involved and uninvolved lower extremities. No significant difference in muscle strength was documented either isometrically or isokinetically, but balance differences were found between the two extremities in a majority of subjects. The findings suggest that muscular weakness is not a major contributing factor to the chronically unstable ankle. The findings do support the presence of proprioceptive deficits associated with this condition. Based on the results, proprioceptive activities should be a primary consideration in management of the chronically unstable ankle.

J Orthop Sports Phys Ther 1990;11(12):605-611.

Recent criticism in the literature regarding the effectiveness and costs of ankle taping has lead to an increased use of commercial ankle braces. This study compared the effectiveness of four commercially available ankle braces in limiting range of motion at the ankle before and after a brief exercise session. Twenty-seven healthy subjects, ages 18-36, were tested across all four bracing conditions. For each brace application, a combined passive inversion-eversion movement was evaluated three times: 1) prebrace application, 2) immediate postbrace application, and 3) following a 10 min exercise session. Subjective ratings of brace comfort, support, and preference were also documented. All four braces significantly limited more motion compared to the unbraced ankle, both before and after exercise (p ≤ 0.05). Additionally, the Aircast^® Sport-Stirrup and Ankle Ligament Protector significantly limited more ankle motion than the Swede-O Ankle Support^® and Kallassy Ankle Support^®, both before and after exercise (p ≤ 0.05). Subjectively, the Sport-Stirrup was perceived as the brace providing the most support, but the Kallassy was the most comfortable and most preferred of the four braces studied. These findings demonstrate that provided support must be balanced with perceived comfort in the prescription of an ankle orthosis.

J Orthop Sports Phys Ther 1992;15(1):10-18.

Key Words: ankle sprain, range of motion, bracing

The use of thermal modalities to enhance stretching procedures is not well documented clinically. This study documented the effectiveness of applying superficial heat and cold in conjunction with a low-load prolonged stretch (LLPS) for increasing shoulder flexibility. Ninety-two healthy males were randomly assigned to one of five groups: 1) an LLPS alone, 2) heat applied in the initial phase of an LLPS, 3) cold applied in the final phase of stretch, 4) a combination of heat initially followed by cold, and 5) no intervention. Subjects received three, 40-minute treatments across a 5-day period. A follow-up measurement was taken 3 days later. Results demonstrated that an LLPS associated with the use of heat, ice, or a combination of both facilitated greater long-term improvements in flexibility compared with controls. However, only subjects receiving heat in the initial phase of an LLPS showed significant gains when compared with those who received stretching alone (p ≤ 0.05). We concluded that applying heat in conjunction with an LLPS to a nonpathologic shoulder is a clinically superior method of improving flexibility compared with an LLPS alone.

J Orthop Sports Phys Ther 1992;16(5):200-207.

Key Words: thermal modalities, prolonged stretch, shoulder joint flexibility

Functional instability is a common complication following an acute ankle sprain. Three potential contributing factors underlying the ankle which chronically gives way are proprioceptive deficits, muscle weakness, and ligamentous laxity. This study's purpose was to document the presence or absence of these concerns in a sample of subjects with unilateral functional ankle instability. Both ankles of 42 subjects were randomly assessed for passive movement sense into inversion and generation of peak torque by the evertors isokinetically. Thirty-four subjects were available for documentation of talar tilt of both ankles through inversion stress radiographs. Analysis found significantly greater mean values for passive movement sense and talar tilt for the involved ankles compared with the uninvolved, while no significant strength differences in peak torque of the evertors were present. Fifty-eight percent of the sample demonstrated clinical impairments in at least 1 of these 3 categories. In conclusion, deficits in passive movement sense and anatomic stability are greater concerns than strength deficits when managing the ankle with functional instability.

J Orthop Sports Phys Ther. 1995;21(4):206-215.

Key Words: ankle, instability, impairment

Objectives: To describe cervical foraminal dimensions in vivo of nonimpaired, asymptomatic individuals in a neutral cervical spine position using magnetic resonance images, and then to document dimensional changes of the foramina when placing the neck in a retracted position.

Background: Physical therapists frequently use movement interventions to treat spine dysfunction. The influence of positional changes of the head and neck on the dimensions of the cervical neural foramina is not well documented.

Methods and Measures: Twenty asymptomatic subjects (10 men and 10 women), 22 to 25 years of age (mean ± SD = 23.7 ± 0.8), underwent magnetic resonance imaging of the cervical spine in both neutral and retracted positions. Bilateral measurements were documented in both positions and compared for height, width, and area of each subject’s intervertebral foramen from C2–C3 to C7–T1.

Results: No significant differences (P >0.004) were found between the 2 neck positions. With the single exception of foraminal area at C3–C4, the mean values of height, width, and area in the retracted position were equal to or larger than those of the cervical neutral position.

Conclusions: Therapeutic maneuvers using retraction of the cervical spine do not promote positional stenosis of the intervertebral foramen in the healthy neck.

J Orthop Sports Phys Ther. 2002; 32(8):380–390.

Key Words: cervical retraction, stenosis, therapeutic exercise