REALIZACIÓN DE LA PRUEBA

A handheld dynamometer (Lafayette Instrument Co., Lafayette, IN) was utilized for all isometric strength testing of the lower extremity. All isometric strength testing procedures have been successfully utilized in previous studies based on manual muscle testing procedure instructions developed by Hislop and Montgomery.46 For all measures of isometric strength, peak force was measured with the dynamometer to the nearest 0.1 kg on both the dominant and non-dominant lower extremity. All testing procedures was carried out by asking the subject to exert as much force as possible against an unmoving resistance, this is otherwise known as a “make test”. One practice trial at 50% of maximum effort was provided for each testing position in order to ensure proper performance of each test. A thirty-second rest period was provided between trials in order to avoid fatigue. The average of three measured trials was utilized for data analysis. Intra-rater and inter-rater reliability for all isometric strength tests are provided in Table 2.22

Table 2. Intra-rater and Inter-rater Reliability of Isometric Strength

HHD Isometric Strength Intra-rater Reliability Inter-rater Reliability

ICC MDC SEM

(kg/body mass) ICC MDC

SEM (kg/body mass) Right Ankle Dorsiflexion 0.87 14.3 5.17 0.35 15.4 5.54 Left Ankle Dorsiflexion 0.91 11.9 4.29 0.29 18.7 6.75 Right Ankle Plantarflexion 0.98* 8.90* 3.20* -- -- -- Left Ankle Plantarflexion 0.98* 8.90* 3.20* -- -- --

Right Ankle Inversion 0.94 9.9 3.57 0.25 16.4 5.93

Left Ankle Inversion 0.91 9.9 3.59 0.34 18.9 6.82

Right Ankle Eversion 0.66 14.7 5.31 0.25 13.0 4.70

Left Ankle Eversion 0.79 11.8 4.25 0.20 13.2 4.76

Right Knee Flexion 0.95 76 2.73 0.66 13.7 4.94

Left Knee Flexion 0.94 7.1 2.56 0.62 13.8 5.00

Right Knee Extension 0.97 15.7 5.65 0.95 27.0 9.75

Left Knee Extension 0.96 22.0 7.94 0.98 16.8 6.05

Right Hip Abduction 0.91 5.1 1.84 0.60 11.0 3.95

Left Hip Abduction 0.84 8.4 3.06 0.91 6.0 2.18

Right Hip Adduction 0.87 6.6 2.38 0.76 7.7 2.79

Left Hip Adduction 0.95 4.2 1.53 0.87 6.0 2.18

Right Hip Internal Rotation 0.60 5.2 1.87 0.48 6.9 2.50 Left Hip Internal Rotation 0.74 5.9 2.12 0.77 6.6 2.40 Right Hip External Rotation 0.71 6.1 2.20 0.77 6.7 2.42 Left Hip External Rotation 0.86 4.4 1.58 0.82 5.9 2.14

* Indicates ICC, MDC, and SEM calculated from different data than remainder of strength measurements SEM calculated as the square root of the mean squared error

Ankle dorsiflexion strength was measured with the subject in upright-seated position while the hips and knees are extended and the foot to be tested is off the end of the table. The examiner stabilized the lower limb of the foot to be tested just proximal to the ankle joint. The handheld dynamometer was placed on the dorsal aspect of the foot just proximal to the metatarsal heads. The examiner passively moved the limb to the starting position, which is in midrange ankle dorsiflexion. Each subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation of this test is provided in Figure 6.

Figure 7. Ankle Plantarflexion Isometric Strength

Ankle plantarflexion strength as measured with the subject in prone position while the hips and knees are extended and the foot to be tested is off the end of the table. The examiner stabilized the lower limb of the foot to be tested just proximal to the ankle joint. The handheld dynamometer was placed on the plantar aspect of the foot just proximal to the metatarsal heads. The examiner passively moved the limb to the starting position, which is in midrange ankle plantarflexion. Each subject was instructed to exert a maximal force against the handheld

dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation of this test is provided in Figure 7.

Figure 8. Ankle Inversion Isometric Strength

Ankle inversion strength was tested with the subject positioned in the supine position with the hips and knees extended and the foot to be test off the end of the table. The examiner stabilized the lower limb of the foot to be tested just proximal to the ankle joint. The handheld dynamometer was positioned on the medial border of the foot at the midpoint of the shaft of the first metatarsal. The examiner passively moved the limb to the starting position, which is midrange ankle inversion. Each subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation of this test is provided in Figure 8.

Figure 9. Ankle Eversion Isometric Strength

Ankle eversion strength was tested with the subject positioned in a supine position with the hips and knees extended and the foot to be tested off the end of the table. The examiner stabilized the lower limb to be tested just proximal to the ankle joint. The handheld dynamometer was positioned on the lateral border of the foot at the midpoint of the fifth metatarsal. The examiner passively moved the limb to the starting position, which is midrange ankle eversion. Each subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation of this test is provided in Figure 9.

Knee flexion strength was tested with the subject in a prone position with the leg being tested bent to 45° of knee flexion. This initial test position acted as the starting positon for the test. The handheld dynamometer was placed just distal to the calcaneous of the leg to be tested. The subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation of this test is provided in Figure 10.

Figure 11. Knee Extension Isometric Strength

Knee extension strength was tested with the subject positioned in an upright-seated position with both the lower legs off the edge of the table. Due to the strength of this muscle, a therapy belt provided resistance during this isometric strength test. The therapy belt was attached to the handheld dynamometer, which was positioned on the most distal aspect of the tibia and anchored to the leg of the treatment table. The subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation of this test is provided in Figure 11.

Figure 12. Hip Abduction Isometric Strength

Hip abduction strength was tested with the subject positioned side lying with the leg to be tested on top. The test leg was supported by a pillow under the lower limb in order to support a neutral spine throughout the duration of the test. The bottom leg was positioned in 90 degrees of knee flexion. The handheld dynamometer was placed just superior to the lateral malleolus. The subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation of this test is provided in Figure 12.

Hip adduction strength was tested with the subject positioned side lying with the leg to be tested on the bottom. The top leg was positioned in 90 degrees of knee flexion with a pillow at the knee in order to support a neutral spine throughout the duration of the test. The handheld dynamometer was placed just superior to the medial malleolus. The subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation is provided in Figure 13.

Figure 14. Hip Internal Rotation Isometric Strength

Hip internal rotation strength was tested with the subject positioned prone on a treatment table with the knee of the test leg flexed to 90 degrees. The examiner passively positioned the test leg into a neutral hip internal-external rotation prior to the initiation of the test. The handheld dynamometer was placed just distal to the lateral malleolus. The subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary position with the handheld dynamometer. Visual representation is provided in Figure 14.

Figure 15. Hip External Rotation Isometric Strength

Hip external rotation strength was tested with the subject positioned prone on a treatment table with the knee of the test leg flexed to 90 degrees. The examiner passively positioned the test leg into a neutral hip internal-external rotation prior to the initiation of the test. The handheld dynamometer was placed just distal to the medial malleolus. The subject was instructed to exert a maximal force against the handheld dynamometer while the examiner maintained a stationary positon with the handheld dynamometer. Visual representation is provided in Figure 15.