*Article* **Supervised Exercise Training Improves 6 min Walking Distance and Modifies Gait Pattern during Pain-Free Walking Condition in Patients with Symptomatic Lower Extremity Peripheral Artery Disease**

**Stefano Lanzi 1,\* , Joël Boichat <sup>1</sup> , Luca Calanca <sup>1</sup> , Lucia Mazzolai <sup>1</sup> and Davide Malatesta <sup>2</sup>**

	- **\*** Correspondence: stefano.lanzi@chuv.ch; Tel.: +41-079-556-49-11

**Citation:** Lanzi, S.; Boichat, J.; Calanca, L.; Mazzolai, L.; Malatesta, D. Supervised Exercise Training Improves 6 min Walking Distance and Modifies Gait Pattern during Pain-Free Walking Condition in Patients with Symptomatic Lower Extremity Peripheral Artery Disease. *Sensors* **2021**, *21*, 7989. https:// doi.org/10.3390/s21237989

Academic Editors: Frédéric Dierick, Fabien Buisseret, Liesbet Van der Perre and Andrea Cereatti

Received: 30 September 2021 Accepted: 26 November 2021 Published: 30 November 2021

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**Abstract:** This study aimed to investigate the effects of supervised exercise training (SET) on spatiotemporal gait and foot kinematics parameters in patients with symptomatic lower extremity peripheral artery disease (PAD) during a 6 min walk test. Symptomatic patients with chronic PAD (Fontaine stage II) following a 3 month SET program were included. Prior to and following SET, a 6 min walk test was performed to assess the 6 min walking distance (6MWD) of each patient. During this test, spatiotemporal gait and foot kinematics parameters were assessed during pain-free and painful walking conditions. Twenty-nine patients with PAD (65.4 ± 9.9 years.) were included. The 6MWD was significantly increased following SET (+10%; *p* ≤ 0.001). The walking speed (+8%) and stride frequency (+5%) were significantly increased after SET (*p* ≤ 0.026). The stride length was only significantly increased during the pain-free walking condition (+4%, *p* = 0.001), whereas no significant differences were observed during the condition of painful walking. Similarly, following SET, the relative duration of the loading response increased (+12%), the relative duration of the foot-flat phase decreased (−3%), and the toe-off pitch angle significantly increased (+3%) during the pain-free walking condition alone (*p* ≤ 0.05). A significant positive correlation was found between changes in the stride length (r = 0.497, *p* = 0.007) and stride frequency (r = 0.786, *p* ≤ 0.001) during pain-free walking condition and changes in the 6MWD. A significant negative correlation was found between changes in the foot-flat phase during pain-free walking condition and changes in the 6MWD (r = −0.567, *p* = 0.002). SET was found to modify the gait pattern of patients with symptomatic PAD, and many of these changes were found to occur during pain-free walking. The improvement in individuals' functional 6 min walk test was related to changes in their gait pattern.

**Keywords:** intermittent claudication; vascular rehabilitation; 6 min walking test; functional walking
