# Effectiveness of Lower-Cost Strategies for Running Gait Retraining: A Systematic Review
## 4 Discussion  
This systematic review summarized the results of the effectiveness of the use of lower-cost equipment as an intervention instrument and/or to evaluate the use of feedback in changing the biomechanics of running. It was possible to identify that lower-cost equipment such as a metronomes, smartwatches, digital cameras, socks and insoles instrumented with sensors, and pressure platforms were used in the retraining of the cadence, foot strike pattern, and distribution of plantar pressure during running. We also observed that the majority of studies that performed running retraining interventions with feedback used an accelerometer to provide real-time tibial PPA information. Effectiveness of Lower-Cost Equipment for Alterations in Spatio-Temporal, Kinetic, and Kinematic Variables of the Foot  
Increasing cadence alone by using a metronome can be an effective way to change the foot strike pattern for some runners. In a study by [PERSON] et al. [40], increasing cadence by 10-15% led to a significant change from heel strike to midfoot or forefoot stride by 17.5 and 30%, respectively. In a study by [PERSON] et al. [58], the metronome was set at 180 steps/minute to provide real-time audio feedback during retraining, and the cadence significantly increased by 6.2%. All participants transitioned to a different type of foot strike than a heel strike after retraining. In the studies by [PERSON], [PERSON], and [PERSON] and [PERSON] et al. [56; 59], the metronome was used as an intervention instrument to control the increase in cadence in relation to the preferred cadence. These results provided strong evidence that demonstrated the effectiveness of the metronome for use in running retraining in order to increase cadence. Technological advances have created the possibility of the undertaking of running training outdoors through the insertion of wearables such as smartwatches that allow real-time feedback of certain components of the run [70]. In this way, the smartwatch enables retraining interventions in a runner's normal running environment, thereby potentially increasing the likelihood that individuals will adhere to the new running pattern. In a study by [PERSON] et al. [55], a smartwatch with an accelerometer was used to control cadence, and the experimental group demonstrated an increase of 8.6% in cadence after a six-week intervention. In a study by [PERSON] et al. [54], the experimental group showed the same significant increase in cadence after eight retraining sessions; after one month, the increase was 8.5% in relation to baseline. In a study by [PERSON] et al. [59], participants received a smartwatch to monitor their cadence and running pace at baseline. In a second session, which was performed with a 10% increased cadence using feedback from the metronome, the smartwatch guided the maintenance of cadence in real time. In that study, there was a significant overall increase of 7.3% in cadence between sessions. These results demonstrated strong evidence for the use of some smartwatches in running retraining in order to increase cadence. Digital cameras can be utilized to obtain video of a run in the sagittal plane to evaluate cadence and also to detect the foot strike pattern. In a study by [PERSON] et al. [60], a smartphone device was used to obtain video of a run in the sagittal plane and to evaluate the cadence in a group that performed running retraining to increase cadence. This group was required to follow a music rhythm that was increased by 10% in relation to the baseline cadence. After six weeks of retraining, it was found that the group significantly increased their cadence by 7.3%. In a study by [PERSON] et al. [48], in the group that performed the retraining to transition from a heel strike to a non- heel strike and run at a cadence of 180 steps/minute (increased cadence), 80% of runners changed from a heel strike to a non- heel strike pattern after the two-hour training session.