Three-Dimensional Gait Analysis Following Achilles Tendon Rupture With Nonsurgical Treatment Reveals Long-Term Deficiencies in Muscle Strength and Function

Abstract

Background: Precise long-term assessment of movement and physical function following Achilles tendon rupture is required for the development and evaluation of treatment, including different regimens of physical therapy.

Purpose: To assess intermediate-term (<10 years by conventional thinking) objective measures of physical function following Achilles tendon rupture treated nonsurgically and to compare these with self-reported measures of physical function.

Study design: Cross-sectional study; Level of evidence, 3.

Methods: Two to 5 years after Achilles tendon rupture, 9 women and 43 men (mean age, 49.2 years; range, 26-68 years) were assessed by physical examination, performance of 1-legged jumps, and 3-dimensional gait analysis (including calculation of muscle work). Self-reported scores for foot function (Achilles tendon rupture score) and level of physical activity were collected. Twenty age- and sex-matched controls were assessed in the same manner.

Results: Physical examination of patients with the knee extended revealed 11.1° of dorsiflexion on the injured side and 9.2° on the uninjured side (P = .020), indicating gastrocnemius muscle lengthening. The 1-legged jump distance was shorter on the injured side (89.5 vs 96.2 cm; P < .001). Gait analysis showed higher peak dorsiflexion (14.3° vs 13.3°; P = .016) and lower concentric (positive) plantar flexor work (16.6 vs 19.9 J/kg; P = .001) in the ankle on the uninjured side. At the same time, eccentric (negative) dorsiflexor work was higher on the injured side (13.2 vs 11.9 J/kg; P = .010). Self-perceived foot function and physical activity were lower in patients than in healthy controls (mean Achilles tendon rupture score, 78.6 and 99.8, respectively).

Conclusion: Nonsurgically treated patients with Achilles tendon rupture showed signs of both anatomic and functional lengthening of the tendon. Attenuated muscle strength and function were present during walking as long as 2 to 5 years after rupture, as determined by 3-dimensional gait analysis. More extensive future studies involving patients having both surgical and nonsurgical treatment could provide additional valuable information.

Keywords: 1-legged long jump; ATRS; Achilles tendon rupture; activity level; dorsiflexion; gait analysis.

Figure 1.

Placement of markers for collection of kinematic data.

Figure 2.

Ankle kinematics in the sagittal plane. Ankle movement (y-axis) during the gait cycle (x-axis) on the injured and uninjured side of 1 representative patient. (a) Dorsiflexion at initial contact; (b) plantar flexion in loading response; (c) peak and timing of dorsiflexion; (d) plantar flexion; (e) dorsiflexion in terminal swing.

Figure 3.

Ankle kinetics in the sagittal plane. Power (y-axis) during the gait cycle (x-axis) on the injured and uninjured sides of 1 representative patient. The values for the control group ± 2 standard deviations (SD) are indicated and the peak power generation marked with an arrow. Clearly, the positive work (the area under the curve above the x-axis) is less on the injured than the uninjured side.