A Novel Walking Cane With Haptic Biofeedback Reduces Degenerative Loading in the Arthritic Knee
Condition: Knee Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Interventional

Summary: 
      The most commonly prescribed mobility aid, the walking cane, is often underloaded and
      therefore fails to reduce knee joint loading and provide symptomatic relief for those with
      knee osteoarthritis. For this study, a novel walking cane with haptic biofeedback was
      designed to improve cane loading. The purpose of this study was twofold; 1) to determine the
      effectiveness of a novel walking haptic biofeedback cane to encourage proper cane loading
      compared with a conventional cane, and 2) to determine whether scale training or haptic
      feedback influences short term retention of cane loading. It is hypothesized that haptic
      biofeedback would increase cane loading (H1) and decrease knee loading (peak knee adduction
      moment (H2) and knee adduction angular impulse (H3)) when compared to naïve cane use.
    

Detailed description: 
      -  Up to 40 individuals who have experience using a walking cane and who self-report a
           clinical diagnosis of knee OA can participate in this study. Participants will be
           excluded if they had a knee replacement in the knee diagnosed with OA, had undergone
           knee surgery within the past year, could not perform cane walking continuously for 30
           minutes, or exhibited other neurological and/or rheumatologic conditions that would
           impact gait.

        -  Participant biometrics, such as height, weight, and age will be collected in addition to
           information about OA and cane use history. Participants will complete the Western
           Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, from which
           scores between 0 and 96 can be used to evaluate the impact of knee OA on the
           individual's quality of life.

        -  A haptic biofeedback cane was designed and manufactured to measure the user applied
           axial cane load, compare the load to the targeted 20% BW threshold, and then deliver a
           vibrotactile feedback in the cane handle when the loading was greater than threshold.
           The cane data acquisition was temporally synchronized to the motion analysis system and
           recorded axial cane loads at 100 Hz for later analysis. The haptic biofeedback cane
           consisted of a conventional bariatric walking cane (Patterson Medical Ltd) with a
           loadcell (Digi-Key100 LBS. Load Cell) placed inside a 3D printed modular cane foot. A
           microcontroller (Sparkfun™ Pro Micro), SD disk storage (Sparkfun™ OpenLog), eccentric
           rotating mass vibration motor (model 306-109, Precision Microdrives Limited), USB
           communications port, and battery completed the system.

        -  Each participant will attend a single laboratory data collection session for the
           acquisition of kinematic, kinetic, and biometric data. First, the participant will be
           asked to walk 20 m down a hallway with a conventional cane to establish a self-selected
           walking speed (SSWS). Participants will then change into motion capture conducive
           clothing and retro-reflective markers were placed using a modified Plug-In-Gait model
           with additional markers on the foot, thigh, and shank, via the Kadaba Model, for
           observation of the Kenn Adduction Moment (KAM) during level ground walking. Markers will
           also placed on the cane to track its motion.

        -  Participants will then be instructed to walk at their SSWS along an approximately
           9-meter walkway containing five force-plates but will remain naïve as to the purpose of
           the plates throughout data collection, to avoid influencing gait. Data were collected
           under each of the following five conditions: 1) naïve, 2) scale training, 3) scale
           recall, 4) haptics training, and 5) haptics-only (Table 2). The order of the scale and
           haptics conditions was randomized at the beginning of data collection to avoid a
           learning bias. During all conditions the instrumented cane will be used, and axial
           loading recoded. However, haptic biofeedback from the cane will only be provided in the
           haptic conditions.

        -  For scale and haptic conditions, the participants will be instructed to hold the cane in
           the hand opposite their most affected knee. Before the recall and haptics-only
           conditions, a five-minute break will be given to test short-term instruction retention.
           For each condition, between five and eight successful steps will be collected. A
           successful walk trial is defined as at least one gait cycle with the affected limb's
           foot cleanly striking the force plate and the cane contacting the floor, not the force
           plate, during stance phase. Successful trials will also have to be within ± 10% of the
           subjects SSWS.

        -  Naïve condition

        -  Participants will be instructed to "walk across the lab and use the cane as is typical."
           During these trials the cane will record axial load but provided no biofeedback (i.e.
           the cane will act as a conventional cane).

        -  Scale conditions

        -  During scale training, participants will practice applying 20% BW to their canes while
           standing, using a beam scale set to the correct weight, until they feel comfortable
           recreating the technique. Participants then practice applying the 20% BW to their canes
           while walking, no external feedback regarding the load applied to the cane will be
           provided, however feedback on cane technique will be. Data will be collected during
           these walking trials. In the scale recall trials participants are to load the cane to
           20% during walking without any feedback from a scale or the cane.

        -  Haptic conditions

        -  During haptic training, participants will be instructed to walk around the lab and load
           the cane during each step until they feel a vibration in the handle. The participants
           will then familiarize themselves with the biofeedback mechanism and practice loading the
           haptic cane while walking around the lab space. In the haptic-only trails participants
           will be instructed to load the cane during walking until they feel a vibration in the
           handle

        -  Three-dimensional kinematics will be collected using a camera 12 Vicon Nexus system
           (Vicon Motion Systems, Oxford, United Kingdom) with a sampling frequency of 120 Hz. Five
           force plates (AMTI) sampling at 1200 Hz were used for collection of ground reaction
           forces (GRFs) and identification of gait events during walking trials. Two time gates
           placed 2 meters apart will measure walking speed.

        -  The KAM will be calculated for the arthritic knee during stance phase of each processed
           step using the inverse kinematics packages in Visual 3D then normalized to body weight
           and height. KAMs will then be exported to MATLAB for further processing and analysis.
           Cane load will be normalized by weight and peak cane load per step will be determined in
           MATLAB. PKAM is calculated as highest KAM and KAAI is calculated as the area under the
           KAM curve.
    

Intervention name(s): Haptic cane; typical cane
Intervention type(s): Device; Device
Intervention description(s): • A haptic biofeedback cane was designed and manufactured to measure the user applied axial cane load, compare the load to the targeted 20% BW threshold, and then deliver a vibrotactile feedback in the cane handle when the loading was greater than threshold. The cane data acquisition was temporally synchronized to the motion analysis system and recorded axial cane loads at 100 Hz for later analysis. The haptic biofeedback cane consisted of a conventional bariatric walking cane (Patterson Medical Ltd) with a loadcell (Digi-Key100 LBS. Load Cell) placed inside a 3D printed modular cane foot. A microcontroller (Sparkfun™ Pro Micro), SD disk storage (Sparkfun™ OpenLog), eccentric rotating mass vibration motor (model 306-109, Precision Microdrives Limited), USB communications port, and battery completed the system.; Typical training cane loading training
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: 1: Naïve - Conventional cane with no instruction given. 2A: Scale training - Conventional cane, scale training, and instruction on proper cane use.
2B: Scale recall - Conventional cane with no further instruction or practice given 3A: Haptics training - Haptic biofeedback cane with explanation and training. 3B: Haptics recall - Haptic biofeedback cane with no further instruction or practice given.
Masking: None (Open Label)
Primary purpose: Device Feasibility
Keywords: Knee Osteoarthritis; Knee adduction moment; Knee loading; Walking cane