Clinical Research

Allows hands free mobility with patients being able to do activities of daily living that can impact a patient’s wellbeing and improve compliance

Unlike crutches and knee scooters, the iWALK is a hand free mobility device. Thus, activities of daily living (ADLs and IADLs) that are impossible to do with crutches and knee scooters such as shopping, working, cooking, child care, etc. are possible with the iWALK. A randomized control trial with 80 patients with both upper and lower limb injuries showed that they were able to complete activities around the house using the iWALK (Rambani et al., 2007) and patients had a more positive attitude to life due to the improved independence with the iWALK (Barth et al., 2019). This could be just one of the reasons why the iWALK has a higher preference rating than crutches (Martin et al., 2019).

Increases muscle activity (which leads to decreased muscle atrophy, increased blood flow, and faster healing)

Research proves that the iWALK provides statistically significant increases in muscle activity for the hip, quadriceps and calf muscles in the non-weight bearing leg with muscle activity patterns consistent with normal unassisted ambulation in terms of both intensity and activation per EMG recordings (Dewar et al., 2021; Dewar & Martin, 2020; Sanders et al., 2018). On the other hand, crutches and knee scooters lead to statistically significant reductions in muscle activity in the non-weight bearing leg compared to normal unassisted ambulation (Clark et al., 2004; Dewar et al., 2021; Dewar & Martin, 2020; Sanders et al., 2018; Seynnes et al., 2008). The heightened level of muscle engagement in the non-weight bearing leg using the iWALK compared to crutches could potentially lead to decreased atrophy, increased blood flow, less cases of deep vein thrombosis and enhanced healing (Broderick et al. 2009; Dewar et al., 2021; Dewar & Martin, 2020; Faghri et al., 1997; Vinay et al., 2021).

The heightened recruitment of the muscles in the non-weight bearing leg when using the iWALK compared to crutches is expected to decrease the level of disuse muscle atrophy
(Altinkaynak, 2022; Dewar et al., 2021; Dewar & Martin, 2020).

Prior research shows that the degree a muscle will atrophy is dependent on the activity of the muscle (Clark, 2009; MacLennan et al., 2020; Magill et al., 2019; Sanders et al., 2018). This is further supported by prior research that shows a muscle fixed in a shorted position atrophies faster than if a muscle is fixed in a lengthened position (Booth, 1982; Booth & Gollnick, 1983). Thus, the knee flexion angle was shown to play an important role in muscle atrophy (Magill et al., 2019).

Because the iWALK fixes the knee angle at 90° flexion which lengthens the muscle, the muscle atrophy after a period of non-weight bearing is expected to be less compared to crutches that fixes the knee angle at approximately 30° (Altinkaynak, 2022). This could partially explain why crutches have been shown to have led to significant muscle atrophy with reductions in muscle size and strength as well as structural changes in muscle fibers in various prior studies (De Boer et al., 2008; Hather et al., 1992; Tesch et al., 2016).

Increases blood flow (reduced risk of developing blood clots and enhance healing)

Using the iWALK leads to increased blood flow in the non-weight bearing limb. Research has shown that the iWALK provides the greatest muscle activity in the lateral gastrocnemius muscle compared to both crutches and knee scooters (Dewar et al., 2021; Dewar & Martin, 2020) and associated research has shown that musculovenous pump activation has a major impact on blood flow while having a larger effect on flow than knee flexion angle (Reb et al., 2021). This corroborates the findings of prior works which reported a significant decline in blood flow for knee scooters (Ciufo et al., 2019) with crutches leading to the greatest decrease secondary to the static position the leg is held in (Reb et al., 2021). When poor blood flow continues, it can cause DVT (blood clots) in the lower extremities (Broderick et al., 2009; Faghri et al., 1997; McLachlin et al., 1960; Vinay et al., 2021) and cause pain venous congestion and life-threatening pulmonary embolisms (PE). It is generally understood that the incidence of DVT is higher for patients with lower limb non-weight bearing injuries than for the general population. Reduced blood flow can also impact oxygen delivery to the injured muscle and bone which is important for healing (Lu et al., 2013).

Faster recovery that can allow quicker returns to work and reduce costs to the healthcare system

A randomized control trial conducted using 80 patients showed that patients were discharged significantly faster after using the iWALK compared with using other mobility devices (Rambani et al., 2007). Reductions in muscle atrophy and improvement in blood flow when using the iWALK impacts the total recovery time for lower limb injuries with quicker rehabilitation, faster healing and less cases of blood clots (Dewar et al., 2021; Dewar & Martin, 2020). The increased muscle oxygenation saturation using the iWALK via improved blood flow also enhances healing (Lu et al., 2013). Crutches cause reductions in cross-sectional area of the quadriceps femoris muscle of about 0.4% per day (Clark et al., 2004). Because the iWALK reduces muscle atrophy, it leads to faster therapeutic gains. Moreover, secondary injuries as a result of using crutches are nonexistent when using the iWALK which also contributes to reducing the recovery times of lower limb injuries.

Eliminates crutch and knee scooter associated secondary injuries

Crutches lead to seven-fold increase in the force that runs through the axilla (Rambani et al., 2007). This increased force at the axilla has been shown to lead to secondary injuries such as axillary artery thrombosis (McFall et al., 2004; Tripp & Cook, 1998) and crutch palsy (Raikin & Froimson, 1997). Other complications as a result of crutch use are carpal tunnel syndrome (Gellman et al., 1988) and shoulder joint degeneration (Shabas & Scheiber, 1986). Secondary injuries also occur with knee scooters due to the increased risk of falling (Rahman et al., 2020; Yeoh et al., 2017). Because there is no loading of the hands and upper extremity when using the iWALK, secondary injuries have not been reported with the iWALK.

Increases compliance to non-weight bearing that can allow less complications and subsequently faster recovery

The iWALK improves patient compliance to non-weight bearing restrictions, due to prior research that shows that patients with lower limb injuries prefer the iWALK over crutches and the important role patient preference plays on patient compliance (Martin et al., 2019). In addition to this, because patients are able to function independently using the iWALK with the ability to do activities of daily living (Rambani et al., 2007), the iWALK will lead to better compliance. Patients with lower extremity injuries have been known to be noncompliant with prescribed weight bearing restrictions (Chiodo et al., 2016; Gershkovich et al., 2016; Kubiak et al., 2013). Lack of compliance leads to complications such as wound breakdown, loss of fracture fixation or hardware failure (Gershkovich et al., 2016).

Reduces the energy cost of ambulation that can allow patients to ambulate for longer durations and increase compliance

Increased physiological demand has been shown to be an important factor in discontinuance and noncompliance to weight bearing restrictions with the use of assistive devices (Bateni & Maki, 2005). Therefore, mobility devices designed to assist ambulation should keep energy expenditure to a minimum while still allowing normal walking speeds and the ability to do their activities of daily living. Prior research shows that the physiological demand and exertion are lowest for the iWALK compared to crutches (Kocher et al., 2016; Martin et al., 2019). Crutches lead to lower gait speed and increased rate of perceived exertion (Bhambani & Clarkson, 1989). This is further supported in other prior studies where crutches have significantly higher energy costs compared to normal unassisted ambulation (Dounis et al., 1980; Holder et al., 1993; Mcbeath et al., 1974; Nielsen et al., 1990; Sankarankutty et al., 1979; Thys et al., 1996). When crutch users were asked to ambulate for 6 minutes, some of the participants needed to stop before they could complete the 6 minutes due to fatigue (Martin et al., 2019). A similar result was not observed when the same participants were asked to ambulate with the iWALK (Martin et al., 2019).

Reduces the structural plastic changes in gray matter and white matter after a period of non-weight bearing

It is well accepted that limb immobilization effects human brain plasticity (Langer et al., 2012). In particular, it was shown that the cortical thickness (gray matter) of the sensorimotor cortex and fractional anisotropy (white matter) decreased after a period of immobilization which are both responsible for processing somatosensory information and impact motor movement (Langer et al., 2012). Because the iWALK is the only mobility device that leads to muscle activity in the non-weight bearing limb consistent with normal walking when compared to crutches and knee scooters (Dewar et al., 2021; Dewar & Martin, 2020), the reorganization of the sensorimotor system as well as the overall effect of remaining non-weight bearing for prolonged periods on human brain plasticity is minimized with the iWALK when compared to crutches and knee scooters.