Figure 1
A. Anterior-posterior unstable condition shoes; B. Medial-lateral unstable condition shoes.
Figure 2
PRISMA flow diagram description of the review search process.
Table 1
Specific questions and rank of Quality Index checklist.
| NUMBER | RANK OF QUALITY INDEX CHECKLIST (SCORES) | SPECIFIC QUESTIONS |
|---|---|---|
| 1 | 1(1 or 0) | Is the hypothesis/aim/objective of the study clearly described? |
| 2 | 2(1 or 0) | Are the main outcomes to be measured clearly described in the Introduction or Methods section? |
| 3 | 3(1 or 0) | Are the characteristics of the patients included in the study clearly described? |
| 4 | 5(2 or 1 or 0) | Are the distributions of principal confounders in each group of subjects to be compared clearly described? |
| 5 | 6(1 or 0) | Are the main findings of the study clearly described? |
| 6 | 7(1 or 0) | Does the study provide estimates of the random variability in the data for the main outcomes? |
| 7 | 10(1 or 0) | Have actual probability values been reported (e.g. 0.035 rather than <0.05) for the main outcomes except where the probability value is less than 0.001? |
| 8 | 11(1 or 0) | Were the subjects asked to participate in the study representative of the entire population from which they were recruited? |
| 9 | 12(1 or 0) | Were those subjects who were prepared to participate representative of the entire population from which they were recruited? |
| 10 | 16(1 or 0) | If any of the results of the study were based on data dredging, was this made clear? |
| 11 | 18(1 or 0) | Were the statistical tests used to assess the main outcomes appropriate? |
| 12 | 20(1 or 0) | Were the main outcome measures used accurate (valid and reliable)? |
| 13 | 21(1 or 0) | Were the patients in different intervention groups (trials and cohort studies) or were the cases and controls (case-control studies) recruited from the same population? |
| 14 | 22(1 or 0) | Were study subjects in different intervention groups (trials and cohort studies) or were the cases and controls (case-control studies) recruited over the same period of time? |
Table 2
Results of the quality assessment based on the modified Quality Index checklist.
| AUTHORS | YEAR | 1 | 2 | 3 | 5 | 6 | 7 | 10 | 11 | 12 | 16 | 18 | 20 | 21 | 22 | TOTAL (15) | PERCENTAGE (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Zhou et al. | 2021(a) | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 12 | 80 |
| Xu et al. | 2021 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 12 | 80 |
| Zhou et al. | 2021(b) | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 12 | 80 |
| Gu et al. | 2014 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 13 | 87 |
| Li et al. | 2015 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 13 | 87 |
| Mei et al. | 2015 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 12 | 80 |
| Jiang et al. | 2021(a) | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 12 | 80 |
| Jiang et al. | 2021(b) | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 11 | 73 |
| Zhou et al. | 2018 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 13 | 87 |
| Zhang et al. | 2012 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 12 | 80 |
| Lee et al. | 2019 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 12 | 80 |
| Pyo et al. | 2008 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 11 | 73 |
| Nigg et al. | 2006 | 1 | 1 | 1 | 2 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 11 | 73 |
| Branthwaite et al. | 2013 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 11 | 73 |
| Nigg et al. | 2010 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 13 | 87 |
| Sousa et al. | 2014 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 12 | 80 |
| Landry et al. | 2010 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 11 | 73 |
Table 3
Summary of the included studies related to medial-lateral unstable condition.
| AUTHOR(S) | TYPE OF UNSTABLE SHOES | PARTICIPANTS | TESTING PROTOCOL | JOINT | OUTCOME | MAIN FINDINGS | ||
|---|---|---|---|---|---|---|---|---|
| KINEMATICS | KINETICS | MUSCLES | ||||||
| Gu et al., 2014 | Unstable structure shoes | 22 males | Walking on a 10m walkway | Ankle, knee and hip | Walking speed, cadence, stride length, foot-off time, stride time and angle | / | Tibialis anterior, peroneus longus, medial and lateral gastrocnemius, vastus medialis, rectus femoris, vastus lateralis and biceps femoris | Unstable training equipment could improve postural control by altering lower leg kinematics and rearranging muscle activation. |
| Li et al., 2015 | Unstable shoe | 16 females | Walking | Knee | / | Moment and plantar pressure distribution | / | Plantar pressure moved from the medial foot to the lateral foot while wearing soft unstable shoes, as opposed to hard unstable shoes. |
| Mei et al., 2015 | Unstable shoe | 22 males | Walking over a 12m walkway | / | Contact area | Plantar pressure and pressure-time integral value | / | The location of the unstable element might be easily modified to satisfy varied functional needs. |
| Zhou et al., 2018 | Bionic shoes | 10 males | Walking and jogging | Ankle, knee and hip | Angle | / | / | The results of the research show that people prefer the hard bionic shoes over the softer soles when exercising. |
| Jiang et al., 2021b | Bionic shoes | 16 males | Before and after 5km running | / | / | Ground reaction force | / | Running with bionic shoes may reduce the chance of injury. |
| Jiang et al., 2021a | Bionic shoes | 16 males | Before and after 5km running | Ankle, knee and hip | Angle and range of motion | Moment | / | Wearing bionic shoes might help strengthen muscles and improve postural stability as well as proprioception. |
| Xu et al., 2021 | Bionic shoes | 15 males | Single-leg landing from 35cm platform | Ankle, knee and hip | Angle and range of motion | Power, moment, joint force and energy distribution | / | Bionic footwear alters the lower limb kinematics at first contact and then adjusts the landing strategy for joint work and joint response force, minimizing the risk of lower limb skeletal muscle damage. |
| Zhou et al., 2021b | Bionic shoes | 15 males | Walking and running on a 10m walkway | Ankle, knee and hip | Angle | Moment | Medial and lateral gastrocnemius, vastus medialis, vastus lateralis, rectus femoris, and tibialis anterior | Stability in the lower limb muscles and rehabilitation exercise may be more beneficial with this kind of shoe than other footwears. |
| Zhou et al., 2021a | Bionic shoes | 15 males | Single-leg landing from 40cm platform | Ankle, knee and hip | Angle and range of motion | Moment and ground reaction force | / | During the single-leg landing phase, bionic shoes may produce more knee and hip flexion than conventional shoes. |
Table 4
Summary of the included studies related to anterior-posterior unstable condition.
| AUTHOR(S) | TYPE OF UNSTABLE SHOES | PARTICIPANTS | TESTING PROTOCOL | JOINT | OUTCOME | MAIN FINDINGS | ||
|---|---|---|---|---|---|---|---|---|
| KINEMATICS | KINETICS | MUSCLES | ||||||
| Nigg et al., 2006 | MBT shoes | 5 males and 3 females | Walking and standing | Ankle, knee and hip | Angle | Moment, ground reaction force, angular impulse and center of pressure | Tibialis anterior, gastrocnemius, vastus medialis, biceps femoris and gluteus medius | The locomotor system seemed to benefit from changes and trends in kinematic, kinetic, and electromyographic features caused by the MBT shoe. |
| Pyo et al., 2008 | MBT shoes | 6 males | Walking | / | / | / | Medial and lateral gastrocnemius, soleus, tibialis posterior, flexor digitorum longus, flexor hallucis longus, pectineus, rectus femoris, biceps femoris long head, biceps femoris short head, vastus intermedius, vastus medialis and vastus laterialis | MBT shoes with rounded bottoms activate lower extremity muscles by interrupting the stability of the body; the degree of improvement in this regard is around 7.44 percent. |
| Landry et al., 2010 | MBT shoes | 9 males and 19 females | Standing | / | / | Center of pressure | Flexor digitorum longus, soleus, peroneus group and anterior compartment group | Standing in an unstable MBT shoe engages certain extrinsic foot muscles, which might have consequences for strengthening and training these muscles. |
| Nigg et al., 2010 | MBT shoes | 17 males and 17 females | Standing and walking on a 30m walkway | Ankle, knee and hip | Angle | Moment, center of pressure and moment impulses | / | Female individuals demonstrated a substantially higher anterior-posterior center of pressure excursion than male subjects in bipedal posture. |
| Branthwaite et al., 2013 | MBT shoes | 12 males and 8 females | Walking over a 10m walkway | / | / | / | Tibialis anterior, peroneus longus, medial gastrocnemius, lateral gastrocnemius, soleus, rectus femoris, biceps femoris and gluteus medius | The use of MBT shoes does not have a universally good effect on muscular behavior, and the time point at which this might occur is unpredictable. |
| Zhang et al., 2012 | MBT shoes | 15 males | Walking at 1.3m/s and 1.8m/s | Ankle, knee and hip | Angle and range of motion | Moment and center of pressure | Tibialis anterior and rectus femoris | To maintain mediolateral stability, the foot is challenged by the rocker shoes, which aids in strengthening the muscles of the hips and ankles that are directly engaged. |
| Sousa et al., 2014 | MBT shoes | 30 females | Standing | / | / | Center of pressure | Gastrocnemius medialis, tibialis anterior, rectus femoris and biceps femoris | Increased ankle and muscle group antagonist co-activation levels and improved postural control system performance may be attributed to the long-term usage of MBT shoes |
| Lee et al., 2019 | MBT shoes | A 29-year-old man | Walking | Ankle and knee | Angle | Ground reaction force and contact pressure of joint | / | The maximal pressure exerted on knee and ankle cartilages during a walking cycle was reduced by the MBT shoes. |