The goal of this research protocol is to improve mobility in older individuals through advances in wearable assistive devices by focusing on two specific aims. The first aim is to study if targeted ankle resistance gait training improves walking performance in older individuals. The second aim is to evaluate the potential of wearable assistance at the ankle, knee, and/or hip joints to increase walking performance in older individuals.

The overarching goal of this study is to improve mobility in older adults through advances in wearable assistance (i.e. powered orthoses). This goal will be accomplished by focusing on two specific research aims. The first aim is to study if targeted ankle resistance gait training improves walking performance in older individuals. The second aim is to evaluate the potential of wearable assistance at the ankle, knee, and/or hip joints to increase walking performance in older individuals.

Several powered orthosis conditions will be tested during several modes of walking or running and balance throughout the course of the study. Trials will take place over-ground and/or on a treadmill. Balance trials will take place on a treadmill. Participants will walk for up to 40 minutes. Frequent breaks will be provided between trials and conditions to avoid fatigue; a maximum of 15 minutes of continuous walking will take place between breaks.

Inclusion Criteria:

• Age between 65 and 85 years old, inclusive.
• Must be able to understand and follow simple directions based on parent report and clinical observation during the history and physical examination.
• Able to provide verbal assent, if appropriate. If the participant is non-verbal, parental interpretation of gesticulation for assent will be used.
• The ability to read and understand English.
• Able to walk at least 30 feet with or without a walking aid
• Able to safely fit into a device configuration and tolerate assistance without knee hyperextension while walking

Exclusion Criteria:

• Any neurological, musculoskeletal or cardiorespiratory injury, health condition ( including pregnancy), or diagnosis that would affect the ability to walk as directed for short periods of time. Note: For elderly participants, a history of joint replacement or joint degeneration that does not impair their ability to walk safely is allowable.
• Participant or parent report that the perspective participant's physician has recommended that they not engage in moderate intensity walking exercise.

>65 years old

Approximately 4 weeks