Clinical Trial Details
— Status: Not yet recruiting
Administrative data
| NCT number |
NCT06384872 |
| Other study ID # |
230042_RRI_Interv5 |
| Secondary ID |
|
| Status |
Not yet recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
October 1, 2024 |
| Est. completion date |
December 31, 2025 |
Study information
| Verified date |
April 2024 |
| Source |
Luxembourg Institute of Health |
| Contact |
Laurent Malisoux, PhD |
| Phone |
26970231 |
| Email |
laurent.malisoux[@]lih.lu |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The main purpose of this project is to investigate the influence of cushioning material at
both the rear and the forepart of running shoes on musculoskeletal complaints in leisure-time
runners. Therefore, the objectives are to investigate if
1. "Extra soft" cushioning materials can reduce injury risk compared to stiffer materials;
2. Cushioning under the forepart of the shoe also influences injury risk, independently of
the cushioning at the rear part;
3. Effects of cushioning material and position depend on the runner's body mass;
4. Perception of cushioning is related to both shoe cushioning and injury risk;
5. Other weight-bearing locomotion activities (i.e., number of steps per day besides
running practice) represents an independent risk factor for running-related injury.
This study consists in a 6-month intervention trial during which leisure-time runners are
required to follow their usual training schedule. Before the beginning of the study, the
participants will receive a pair of running shoes. The three running shoe models will be
exactly the same, except for their foam properties at the rear and forepart of the shoe,
which will differ by 33 and 37%, respectively. The study shoes will be administered through
random allocation. The participants will be required to use these shoes for all running
sessions, and only for running activities.
Participants will first fill out a baseline questionnaire. During the intervention, data on
running practice will be downloaded from sports watches and their respective app via Strava.
Information on the use of the study shoes will be collected via a weekly questionnaire.
Participants will be asked to fill out a weekly questionnaire on any musculoskeletal
complaints experienced during the past 7 days. A questionnaire on the perception of
cushioning will be filled in by the participants at three time points (after 5h of running,
25h of running, and at the end of follow-up).
Primary hypothesis:
- Greater shock absorption properties at the rear part of running shoes are associated with a
lower injury risk in recreational runners.
Secondary hypothesis:
- Greater shock absorption properties under the forepart of the shoe are also associated
with lower injury risk in recreational runners.
- Runners with low body mass experience a lower injury risk in shoes with greater shock
absorption properties.
- Greater perceived cushioning is related to lower injury risk.
Description:
Study design:
The design of this study is a randomized trial with an intervention period of six months.
Running footwear is provided by a renowned sport equipment manufacturer working in close
collaboration with the Physical Activity, Sport and Health (PASH) research group of the
Luxembourg Institute of Health (LIH). PASH will be responsible for the management and
execution of the study, including random allocation of the study shoes, recruitment and
follow-up of the participants, as well as data management and analysis. The study design is
based on the comparison of three running shoe versions, which differ with respect to their
foam properties and cushioning position (i.e., rear and forepart of the shoe). The cushioning
properties at the rear and forepart of the three shoe versions will be within the range of
values of models available on the market.
Participants:
Healthy leisure-time runners will be recruited through advertising in local newspapers and
press releases within Luxembourg, as well as via social media during the months of October
2024 to March 2025. The benefits for the participants are highlighted during the recruitment
phase, and are as follows: 1) a free pair of running shoes, and 2) a brief report on the main
findings of the study. However, participants will be made aware that they will randomly
receive one of the three study shoe versions to be worn during the intervention period for
all their running activities.
Volunteers willing to take part in the study will be invited to follow the process described
hereafter:
- Volunteers have to register on the electronic system that will be specifically designed
for the study, and specify that they wish to enroll for the present study. The
inclusion/exclusion criteria and study requirements will be reminded at this stage of
the registration process.
- Volunteers will receive the full information of the study, and informed consent
containing the full name of the participants.
- Volunteers must declare that they freely consent to participate in the study by checking
the appropriate boxes.
- Volunteers will have to fill in a baseline questionnaire.
- Volunteers will have to set an appointment with the research team via the electronic
system.
Sample size:
A sample size calculation for Cox regression was used to determine the number of participants
needed for the primary hypothesis of the study. With an alpha of 0.05 and a power of 80%, an
average injury rate of 30% (see definition of the main outcome below), an expected HR=1.50
between groups, 33% of participants randomized to each shoe group and an expected drop-out
rate of 10%, the total number of participants required is 1068.
Intervention:
The study shoes are prototypes derived from a model available on the market (Kiprun KS 500.2)
and will be anonymized for the purpose of this trial. The sole of the shoes will be
customized for the purpose of the study. The three running shoe models will be exactly the
same, except for their foam properties at the rear and forepart of the shoe, which will
differ by 33 and 37%, respectively, while remaining within the range of the shoes available
on the market (linear equivalent stiffness: 40 to 60 and 50 to 80 N/mm, at the rear and
forepart of the shoe, respectively). We expect a difference in shoe weight lower than 30 g
between the three versions (for size 42). The difference in cushioning properties between
shoe versions will be created by modifying the type of foam and the foaming process. A set of
shoes will be tested for cushioning properties by the manufacturer to provide accurate data
on the technical specifications (stiffness and dissipated energy).
- Model 1: "Hard-Hard" - about 60 and 80 N/mm at the rear and forepart of the shoe,
respectively.
- Model 2: "Soft-Hard" - about 40 and 80 N/mm at the rear and forepart of the shoe,
respectively.
- Model 3: "Soft-Soft" - about 40 and 50 N/mm at the rear and forepart of the shoe,
respectively.
Stratified randomization:
A stratified block randomization will be prepared by a statistician from LIH before the
beginning of the recruitment. Participants will be stratified according to their sex because
body mass largely dependents on sex, and different models will be available for men and women
for each shoe version. Each block will include 40 participants.
Data collection:
Participants will have to fill in a baseline questionnaire that aims to collect information
regarding demographics, running experience, training habits, running competitions performed
and injury history. The recruitment phase of this project will last from October 2024 until
March 2025. The follow-up period will start as soon as the participants have received their
study shoes and will last for 6 months. This means that the data collection phase will finish
at the latest on the 30th of September 2025.
Once a participant receives his/her pair of study shoes, the intervention period begins for
that participant. During this intervention period, the participants are required to use the
study shoes for all their running activities, to continue their usual or follow their planned
training schedule, and to fill out the weekly questionnaire on musculoskeletal complaints, as
well as on the use of the study shoes during the follow-up.
Data on running practice will be downloaded from sports watches (Garmin, Polar and Suunto)
and their respective app via Strava. Information on the use of the study shoes will be
collected via a weekly questionnaire.
Study participation will be terminated and the participant will be right-censored if he/she
does not fill in the weekly injury form for 2 consecutive weeks, does not reply (or react) to
the automatic reminders (2 days after the initial invitation), and could not be reached by
phone by the research team (2 attempts). Indeed, a critical aspect for the validity of the
study is to verify that the injury (the main outcome) is not the reason for dropping out.
Therefore, we will contact these participants to confirm that they reported all injury before
termination of the investigation.
Participants will be asked to fill out a weekly questionnaire on any physical complaints
experienced during the past 7 days (the Oslo Sports Trauma Research Centre (OSTRC) Overuse
Injury Questionnaire). On top of the four basic questions, information regarding the
following is required: data of first onset, sports discipline, anatomical location, type of
injury, new / recurrent / subsequent event, and estimated return date to full participation.
Individual e-mail reminders will be sent to the participants who do not fill out a weekly
questionnaire. Personal phone calls will be made if the participants do not react to the
e-mail reminders and if the reported information in the injury form is found to be
inconsistent.
Study outcomes:
Primary outcome
- First running-related injury occurring during the follow-up, and defined as any
running-related physical complaint in the lower limbs or lower back region that causes a
restriction on or stoppage of running (distance, speed, duration, or training) for at least
seven days. Practically, this corresponds to injury forms where the participant answered
option 3 or 4 in question 1, or option 1, 2 or 3 in question 2 or question 3 of the OSTRC-O
questionnaire.
Secondary outcomes:
- First one-day time loss running-related injury: Any running-related physical complaint
in the lower limbs or lower back region that causes a restriction on or stoppage of
running (distance, speed, duration, or training) for at least one day. More
specifically, this correspond to injury forms with option 3 or 4 in question 1, or
option 1, 2 or 3 in question 2 or question 3 of the OSTRC-O questionnaire, without any
minimal duration.
- First running-related musculoskeletal complaint: Any physical complaint including pain,
ache, joint instability, stiffness, or any other complaint resulting from participating
in running activities, including but irrespective of the need of medical attention
(seeking care from medical practitioner) or time-loss (inability to complete a running
training session or participate in one or more days after the onset of injury). More
specifically, injury forms with option 2 in question 1 of the OSTRC questionnaire will
also be considered as outcome of interest in this case;
- First substantial running-related injury: Injury forms where the participant answered
options 3 or 4 in question 2 or question 3 of the OSTRC-O questionnaire.
- First overuse running-related injury: Injury forms where the participant reported
complaints with obvious acute mechanism such as ankle sprain will be excluded
(considered as competing risk).
Statistical analysis:
Descriptive data for the personal and training-related characteristics will be presented as
count and percentage for dichotomous variables, and as mean and standard deviation, or as
median and range, for normally and non-normally distributed continuous variables,
respectively. Average sport-related characteristics will be computed for each participant
over their specific period of observation. Shock absorption properties of the three shoes
versions (measured and provided by Decathlon) will be compared using an Analysis of Variance.
We will calculate the injury incidence as number of injuries per 1000 hours of running
exposure for each outcome. We will calculate the injury prevalence each week by dividing the
number of participants that reported an injury by the number of respondents that week for
each outcome. We will then calculate the average weekly prevalence for each outcome and
separately for the main anatomic locations.
Competing-risks regression models will be used to investigate the effect of shoe version,
body mass and other possible risk factors by estimating the subdistribution hazard, according
to Fine and Gray. Date of inclusion and date of injury or censoring will be basic data used
to calculate the time at risk, which is expressed in hours spent running and defined as the
time-scale. Participants will be right-censored if lost to follow-up or at the end of the
intervention period. Average sport-related characteristics will be computed for each
participant over their specific period of observation. The assumption of proportional hazards
was evaluated using log-minus-log plots and Schoenfeld's global test. First, unadjusted
subdistribution hazards will be estimated for shoe versions, body mass and other potential
risk factors such as training-related characteristics. Subsequently, the variables with a P
value <0.200, as well as well-established potential confounders, will be included in the
adjusted model to determine whether shoe cushioning is associated with injury risk. The
recommendation for using at least ten injuries per predictor variable included in the
regression analysis will be strictly followed. Finally, a stratified analysis will be
performed to investigate if the effect of shoe cushioning on injury risk is modified by body
mass. Participants will be classified as light or heavy runners using the median value of
body mass as cut-off, independently in men and women. SHRs and their 95% confidence intervals
(CI) will be first determined for each stratum (with the reference being the stratum with the
lower risk). Then, SHRs and their 95% CI will be computed within strata to determine both the
effect of shoe version within each body mass category, and the effect of body mass within
each shoe group.
Sensitivity analysis First, we will exclude the participants who sustained an injury over the
first two weeks to investigate the potential impact of the transition to the study shoe on
the findings. Second, depending on the compliance of the participants to the intervention
(i.e., use of the study shoes for each running session), we will exclude the participants who
did not use the study shoes for (e.g.) minimum 50% of their running sessions.
