Reducing risk of a second ACL rupture when Return to play by examining
the knee biomechanics on sensor-based feedback during jump landings in
adult athletes: A Systematic Review
Maxime Drent (i6242945)
Human Movement Sciences
Faculty of Health, Medicine and Life Sciences
Maastricht university
HMS4707
Date of submission: 02-04-2021
,Abstract
Background: The anterior cruciate ligament (ACL) is the most commonly injured knee ligament requiring
operative intervention. Before an athlete can return to sport they have to meet criteria. This can be
measured by examining landing knee biomechanics. Objective: The aim of this review is to evaluate the risk
of ACL (re)injury when RTP while looking at the biomechanical knee characteristics on sensor-based
feedback during jumping activities within adult athletes Methods: The literature search was conducted from
PubMed and by manually searches. 125 unique articles were identified, of which 11 articles with 390
participants were included. Studies were included if they 1) included adult (18-65 years) athletes with an
ACLR, 2) investigated knee biomechanics, 3) tested during jump landings. Studies were excluded if they
included patients with braces. There were no exclusions based on 1) wearing shoes, 2) specific sensors or
markers. Studies were screened by title, abstract and inclusion/exclusion criteria. The impact size measures
were divided into three categories: small (0.2), moderate (0.5), and strong (0.8 and higher). Results: The
participants performed in 8 studies drop landings, in 2 studies hops for distance and in one a stop-jump. The
knee flexion angle of the ACLR limb was significantly lower than the knee flexion angle of the Non-ACLR.
Participants who subsequently injured an ACL had a significant 6.4 times greater knee abduction moment. It
has been demonstrated that significant increases in ACL strain occur when a valgus moment causes an
increase in knee valgus angle during jump landings. Conclusion: Decreases in knee flexion during jump
landings increase the risk of an ACL (re)injury and athletes with a greater abduction had a higher ACL
(re)injury risk. The increases observed in knee valgus leads to greater ACL rupture risk. A limitation of this
review is that the included studies included low sample sizes.
, Introduction
The anterior cruciate ligament (ACL) is the most commonly injured knee ligament requiring operative
intervention. The loss of this ligament often leads to premature degenerative arthritis of the knee (1). A
cruciate ligament injury often occurs when an athlete suddenly changes direction, while the foot remains
planted on the surface. This can occur when a player falls and deflects himself but it is also possible that it
happens during a collision between players (1, 2). Sports, where a cruciate ligament injury is most common,
are ones with forceful pivoting movements, such as football, handball, skiing, etc. If an ACL reconstruction is
chosen, a long-term rehabilitation of approximately 9-12 months will follow with the ultimate goal of
returning to the sport (2).
Return to Sports (RTS) and Return to Play (RTP) are two terms used by researchers, i.e. return to pre-injury
competition in both training and competing, but not at the optimal level of success. Return to Play (RTP)
should be used as a continuum similar to therapy that is not necessarily a choice made in isolation at the
completion of the recovery period. There are many different opinions about when an athlete can RTP (3).
The published Dutch practice guideline describes the criterion-based rehabilitation of anterior cruciate
ligament repair (ACLR) rather than time-based rehabilitation. As a part of this criterion-based recovery, a
return to play is only recommended when players fulfill the clear Return to Play (RTP) guidelines (4, 5). While
many authorities recommend the use of criterion-based RTP decisions, several ACLR athletes are cleared to
return to pivoting sports without meeting these requirements. In Sweden, only 20% of adults and 28% of
teenagers who had already returned to play met quantitative RTP requirements 12 months after ACLR, while
in the USA, only 14% of teenage athletes met quantitative RTP criteria when RTP was cleared (5, 6).
Recent systematic analyses indicate that the clinicians' RTP determination is hardly focused on objective
clinometric criteria. In addition, these findings concluded that only quantitative criteria are linked to RTP,
while qualitative criteria (e.g. dynamic knee valgus, knee flexion angle, trunk control) are considered to play
an important role in prevention and recovery. The presence of dynamic knee valgus when landing from a
jump, for example, increases the risk of ACL (re)injury (5). In addition, previous studies have found that hip
and knee biomechanics are also predictors of a second ACL injury while landing from a jump in terms of
movement efficiency (4).
the knee biomechanics on sensor-based feedback during jump landings in
adult athletes: A Systematic Review
Maxime Drent (i6242945)
Human Movement Sciences
Faculty of Health, Medicine and Life Sciences
Maastricht university
HMS4707
Date of submission: 02-04-2021
,Abstract
Background: The anterior cruciate ligament (ACL) is the most commonly injured knee ligament requiring
operative intervention. Before an athlete can return to sport they have to meet criteria. This can be
measured by examining landing knee biomechanics. Objective: The aim of this review is to evaluate the risk
of ACL (re)injury when RTP while looking at the biomechanical knee characteristics on sensor-based
feedback during jumping activities within adult athletes Methods: The literature search was conducted from
PubMed and by manually searches. 125 unique articles were identified, of which 11 articles with 390
participants were included. Studies were included if they 1) included adult (18-65 years) athletes with an
ACLR, 2) investigated knee biomechanics, 3) tested during jump landings. Studies were excluded if they
included patients with braces. There were no exclusions based on 1) wearing shoes, 2) specific sensors or
markers. Studies were screened by title, abstract and inclusion/exclusion criteria. The impact size measures
were divided into three categories: small (0.2), moderate (0.5), and strong (0.8 and higher). Results: The
participants performed in 8 studies drop landings, in 2 studies hops for distance and in one a stop-jump. The
knee flexion angle of the ACLR limb was significantly lower than the knee flexion angle of the Non-ACLR.
Participants who subsequently injured an ACL had a significant 6.4 times greater knee abduction moment. It
has been demonstrated that significant increases in ACL strain occur when a valgus moment causes an
increase in knee valgus angle during jump landings. Conclusion: Decreases in knee flexion during jump
landings increase the risk of an ACL (re)injury and athletes with a greater abduction had a higher ACL
(re)injury risk. The increases observed in knee valgus leads to greater ACL rupture risk. A limitation of this
review is that the included studies included low sample sizes.
, Introduction
The anterior cruciate ligament (ACL) is the most commonly injured knee ligament requiring operative
intervention. The loss of this ligament often leads to premature degenerative arthritis of the knee (1). A
cruciate ligament injury often occurs when an athlete suddenly changes direction, while the foot remains
planted on the surface. This can occur when a player falls and deflects himself but it is also possible that it
happens during a collision between players (1, 2). Sports, where a cruciate ligament injury is most common,
are ones with forceful pivoting movements, such as football, handball, skiing, etc. If an ACL reconstruction is
chosen, a long-term rehabilitation of approximately 9-12 months will follow with the ultimate goal of
returning to the sport (2).
Return to Sports (RTS) and Return to Play (RTP) are two terms used by researchers, i.e. return to pre-injury
competition in both training and competing, but not at the optimal level of success. Return to Play (RTP)
should be used as a continuum similar to therapy that is not necessarily a choice made in isolation at the
completion of the recovery period. There are many different opinions about when an athlete can RTP (3).
The published Dutch practice guideline describes the criterion-based rehabilitation of anterior cruciate
ligament repair (ACLR) rather than time-based rehabilitation. As a part of this criterion-based recovery, a
return to play is only recommended when players fulfill the clear Return to Play (RTP) guidelines (4, 5). While
many authorities recommend the use of criterion-based RTP decisions, several ACLR athletes are cleared to
return to pivoting sports without meeting these requirements. In Sweden, only 20% of adults and 28% of
teenagers who had already returned to play met quantitative RTP requirements 12 months after ACLR, while
in the USA, only 14% of teenage athletes met quantitative RTP criteria when RTP was cleared (5, 6).
Recent systematic analyses indicate that the clinicians' RTP determination is hardly focused on objective
clinometric criteria. In addition, these findings concluded that only quantitative criteria are linked to RTP,
while qualitative criteria (e.g. dynamic knee valgus, knee flexion angle, trunk control) are considered to play
an important role in prevention and recovery. The presence of dynamic knee valgus when landing from a
jump, for example, increases the risk of ACL (re)injury (5). In addition, previous studies have found that hip
and knee biomechanics are also predictors of a second ACL injury while landing from a jump in terms of
movement efficiency (4).
