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Sidestep cutting maneuvers in female basketball players: Stop phase poses greater risk for anterior cruciate ligament injury

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Background: Many non-contact anterior cruciate ligament (ACL) injuries in female basketball players occur during sidestep cutting. The objective of this study was to identify the phases of a sidestep cutting maneuver that place athletes at a greater risk for ACL injuries. Methods: Ten healthy female collegiate basketball athletes were asked to perform sidestep cutting movements; the knee flexion and valgus angles as well as the electromyographic activity of the vastus lateral, vastus medial, biceps femoris, and semimembranosus muscles of the non-dominant leg were analyzed during the maneuver. Results: The mean knee valgus angle peak tended to be greater during the stop phase than during the side-movement phase. The quadriceps activation during the stop phase was significantly higher than that during the side-movement phase. Moreover, the ratio of hamstring to quadriceps muscle activation during the stop phase was significantly lower than that during the side-movement phase, as assessed by surface electromyography. Conclusion: Female basketball athletes have a higher risk for ACL injury during the stop phase than during the side-movement phase of the sidestep cutting maneuver. Level of evidence: Level III.
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Sidestep cutting maneuvers in female basketball players: Stop phase poses greater
risk for anterior cruciate ligament injury
Di Xie , Yukio Urabe, Jyo Ochiai, Eri Kobayashi, Noriaki Maeda
Department of Sports Rehabilitation, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8553, Japan
abstractarticle info
Article history:
Received 24 October 2011
Received in revised form 25 June 2012
Accepted 8 July 2012
Keywords:
Anterior cruciate ligament injury
Basketball
Electromyographic
Kinematics
Sidestep cutting maneuver
Background: Many non-contact anterior cruciate ligament (ACL) injuries in female basketball players occur
during sidestep cutting. The objective of this study was to identify the phases of a sidestep cutting maneuver
that place athletes at a greater risk for ACL injuries.
Methods: Ten healthy female collegiate basketball athletes were asked to perform sidestep cutting movements;
the knee exion and valgus angles as well as the electromyographic activity of the vastus lateral, vastus medial,
biceps femoris, and semimembranosus muscles of the non-dominant leg were analyzed during the maneuver.
Results: The mean knee valgus angle peak tended to be greater during the stop phase than during the
side-movement phase. The quadriceps activation during the stop phase was signicantly higher than that dur-
ing the side-movement phase. Moreover, the ratio of hamstring to quadriceps muscle activation during the stop
phase was signicantly lower than that during the side-movement phase, as assessed by surface electromyog-
raphy.
Conclusion: Female basketball athletes have a higher risk for ACL injury during the stop phase than during the
side-movement phase of the sidestep cutting maneuver.
Level of evidence: Level III.
© 2012 Elsevier B.V. All rights reserved.
1. Introduction
Non-contact anterior cruciate ligament (ACL) injuries commonly
occur during stopping, landing, and cutting maneuvers during basketball
drills and competitions [1].Bodenetal.[2] reviewed videotapes of ACL
disruptions and noted that most non-contact injuries occur with the
knee close to extension during a sharp deceleration or landing maneu-
ver. However, anterior drawer load in isolation was insufcient to rup-
ture the ACL without additional valgus load [3]. In addition, knee joint
valgus is often implicated as a hazardous position for the ACL [4,5] and
has been linked to ACL injury risk [6].
Urabe et al. [7] performed electromyographic (EMG) analysis during
jump landing and demonstrated that the ratio of hamstring to quadriceps
muscle activation (H/Q ratio) was signicantly lower in female athletes
even though the knee exion angle was increased compared to that in
the early phase of landing. Anterior tibial translation and ACL strain are in-
creased among female athletes with a low H/Q ratio [8]. The low H/Q ratio
could be one of the reasons female athletes have a higher incidence of
non-contact ACL injury during jump landing [7].Colbyetal.[9] analyzed
quadriceps and hamstring muscle activity during sidestep cutting and
demonstrated that the H/Q ratio was the lowest when the knee exion
angle was 33°. Their study suggested that the risk of ACL injury is higher
at this angle.
Ireland [10] reported an example of an ACL injury to the left knee as
seen from the back and left side of a basketball athlete. In that particular
case, the subject had just rebounded and stopped to change direction to
avoid the defending player. However, in this situation, the injury is not
detected until the athlete takes his or her weight off the injured leg [11].
The body's center of mass moves laterally after one-legged jump landing
or stopping during sidestep cutting maneuvers. Therefore, knee valgus
and exion during these three maneuvers favor ACL injury. Based on
the potential mechanism of ACL injuries during sidestep cutting maneu-
vers, the phases at greater risk for ACL injury may be claried by analyzing
the knee exion angle on the sagittal plane, the knee valgus angle on the
frontal plane, and EMG activation of quadriceps and hamstring muscles.
Thus far, however, few studies have been conducted from the viewpoint
of kinematics and EMG variables during sidestep cutting.
The objective of this study was to identify the phases of a sidestep cut-
ting maneuver that put basketball athletes at a greater risk for ACL injuries
by analyzing knee valgus and exionanglesaswellasthequadricepsand
hamstring activity. We hypothesized that larger knee valgus angles,
smaller knee exion angles, and lower H/Q ratios will appear during de-
celeration phases of sidestep cutting with greater risk of ACL injury.
2. Methods
Ten healthy female collegiate basketball athletes who reported no
orthopedic disease in their lower extremities provided written con-
sent to participate in this study. The subjects' average age, height,
The Knee 20 (2013) 8589
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82 257 5344.
E-mail address: ditianxie@hotmail.com (D. Xie).
0968-0160/$ see front matter © 2012 Elsevier B.V. All rights reserved.
doi:10.1016/j.knee.2012.07.003
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weight, and history of playing basketball were 20.9±2.0 years,
158.4±7.0 cm, 52.8 ± 5.9 kg, and 5.1 ± 0.7 years, respectively. The
power for each analysis of variance was not less than 0.65 if the effect
size was more than 0.80 [12]. A priori power analysis by G*power re-
vealed that obtaining a static power of 0.75 at an effect size of 0.80
with an alpha level of 0.05 required a sample size of at least 10 sub-
jects. Approval for this study was obtained from the institutional re-
view board of the Graduate School of Health Sciences, Hiroshima
University (ID number, 1027).
Four markers were placed on the oor 1 m away from each other. An
electric metronome was set at 180 beats/min, and the participant was
instructed to begin running on the rstbeep.Theparticipantrantwo
steps forward, planted the non-dominant leg on her third step, and
then the dominant leg stepped at an angle of approximately 90°. The
dominant leg was dened as the leg usually used for kicking a soccer
ball [13]. In this study, all of the participants indicated the right leg as
their dominant leg. The non-dominant leg was adopted as plant leg
based on the fact that the majority of surgical limbs in ACL reconstruction
are non-dominant [14]. A cutting trial was deemed successful if the par-
ticipant performed the maneuver at a speed of 23m/s.Fivetrialswere
performed after sufcient practice runs. Fig. 1 shows the protocol used
for sidestep cutting. The stop phase was dened as the period from initial
foot strike to the maximum knee exion. The side-movement phase was
dened as the period from maximum knee exion to toeing off. To sim-
ulate the actual basketball movements, participants were asked to place
their upper limbs in front of their chests as if they were receiving a pass.
Sixteen retro-reective adhesive backbone markers (10 mm in di-
ameter) were placed over the anterior superior iliac spine, posterior
superior iliac spine, lateral and medial condyles of the femur, lateral
and medial condyles of the tibia, and lateral and medial malleoli be-
fore measurement. Three high-speed (200 frames/s) CCD cameras
(Has-200R; Ditect, Tokyo, Japan) were placed at the front and lateral
sides of the subjects to measure the knee exion angle from the sag-
ittal plane and the valgus and varus angles from the frontal plane dur-
ing sidestep cutting.
The raw kinematic data were ltered using a General Cross Validatory
quintic-order spline [15] and analyzed using Dipp-Motion XD software
(Ditect, Tokyo, Japan). For quantication of knee joint angles during
the cutting cycle, a kinematic model was dened from a standing static
trial and from lower limb anthropometric measurement. The hip joint
center was estimated from the markers of anterior superior iliac spine
and posterior superior iliac spine according to Vaughan's method [16].
Joint centers for the knee and ankle were determined in the standing
trial [17].Thefemurcenterwasdened as the midpoint between the lat-
eral and medial condyles of the femur. The tibia center was dened as
the midpoint between the lateral and medial condyles of the tibia. The
talocrural joint center was dened as the midpoint between the lateral
and medial malleoli. Knee exion angles and valgus angles were calculat-
ed in the order xyz axes according to Grood's method [18] after two skel-
etal segments (thigh and tibia) were built.
Bipolar supercial EMG sensors (Blue Sensor; MEDICOTEST, Olstykke,
Denmark) were placed over the vastus lateral (VL), vastus medial (VM),
biceps femoris (BF), and semimembranosus (SM) muscles on each
subject's non-dominant leg, following Perotto's method [19] before
EMG measurements. Maximal muscle activity was measured during a
maximum voluntary isometric contraction (MVIC) against a manual re-
sistance for 5 s [20]. The MVIC tests for the VL and VM oblique muscles
were performed while the subject was in a sitting position with the
knee exed at 90°. The MVIC tests for the BF and SM oblique muscles
were performed while the subject was in a prone position with the
knee exed at 30°. Raw dynamic EMG and EMG gathered during
MVIC were amplied (Bio-amp ML132; AD Instruments, Colorado,
USA), subjected to A/D conversion at 1 kHz, and rectied with a
high-pass lter at 500 Hz and low-pass lter at 20 Hz (Mac Lab/8s;
AD Instruments, Colorado, USA). Then, the data were stored on a per-
sonal computer. Kinematic and EMG data were synchronized using a
digital timing signal counter (custom-made) and recorded using CCD
camera software (Ditect).
To allow for comparison of EMG intensity between phases, EMG
obtained during the sidestep cutting maneuver was normalized to
Fig. 1. Sidestep cutting withup to two approach steps and one leg stopping followedby sidestepping. This movement is observedfrom the anterior(above) and lateral aspects (below). A:
Initialcontact of the leftfoot. B: Maximum exionof the left knee.C: Left foot toeing off whileright foot sidesteps. The stopphase is from A to B,and the side-movement phaseis from B to C.
86 D. Xie et al. / The Knee 20 (2013) 8589
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the EMG acquired during an MVIC (%MVC). For the MVIC, the rectied
EMG signals were integrated every second, and the highest second
of muscle activation (representing 100% EMG activity) was used.
Quadriceps and hamstring muscle activation were calculated using
the method described by Kvist and Gillquist [21]. Quadriceps muscle
activation was calculated as the average of VL and VM muscle activa-
tions. Hamstring muscle activation was calculated as the average of
BF and SM muscle activations.
Average values from ve trials were used for analysis. The statisti-
cal analyses were performed using the Statistical Package for the So-
cial Sciences version 12.0J for Windows. Quadriceps muscle activity,
hamstring muscle activity, and H/Q ratios between the stop and
side-movement phases were compared using paired samples t-test.
Student's t-test was used for the comparison of knee valgus angle
peaks between the stop and side-movement phases. The level of
probability accepted as the criterion for statistical signicance was
pb0.05.
3. Results
The mean knee exion angle at the time of footstriking was 30.0± 7.4°,and the mean
maximum knee exion angle during sidestep cutting was 64.7±8.3°. The temporal
changes in knee valgus and varus angles for all 10 subjects formed a bimodal curve with
one valgus angle peak during the stop phase and another during the side-movement
phase (Fig. 2). The stop phase lasted 127.1± 26.5 ms, and the side-movement phase
lasted 156.3±23.8 ms. The rst knee valgus angle peak was observed at 79.6± 38.2 ms
when kneeexion angle was 56.3±9.9°. The second knee valgusangle peak was observed
at 170.6± 33.7 ms when knee exion angle was 58.6±11.7°. The rst and second knee
valgus angle peaks were 11.7±7.57° and 9.1± 3.5°, respectively. The difference between
the rst and second valgus angle peaks was not signicant (Table 1).
Three of the 10 subjects presented only one knee valgus angle peak during the stop
phase but no knee valgus angle peak during the side-movement phase (Fig. 3). The
stop phase lasted 128.6±36.7 ms, and the side-movement phase lasted 160.0 ±
27.5 ms. The mean knee valgus angle peak of 19.5 ±10.3° was observed at 128.2±
29.1 ms when the knee exion angle was 60.2 ±11.3°.
There was a signicant difference for quadriceps muscle activity between the stop
and side-movement phases (pb0.05) (Table 1). The H/Q ratios during the stop and
side-movement phases were 0.32±0.13 and 0.89± 0.07, respectively; and the H/Q ratio
during the stop phase was signicantly lower than that during the side-movement
phase (pb0.05) (Table 1). In addition, the quadriceps muscle activity was approximately
112% MVC higher than that of the hamstring during the stop phase.
4. Discussion
In 90° sidestep cutting maneuvers, female basketball players
presented temporary changes in the knee valgus and varus angles.
Previous studies have analyzed sidestep cutting maneuver at a
cutting angle of 45° [22] or 3040° [4]. In this study, the cutting
angle of 90° was adopted based on the fact that the 90° sidestep cut-
ting is dangerous and frequently used in athletic events. Regarding
another aspect of sidestep cutting, Olsen et al. [23] observed that
the sequence of events leading to a right-sided ACL injury included
the following: (i) the subject takes two steps with the ball and (ii)
pushes off to prepare for a sidestep cutting at high speed. Before our
measurements, sufcient practice runs were performed to assure
that the participants could gain a high speed of 23 m/s.
In the report by McLean et al., subjects performing sidestep cutting
at 4.55.5 m/s showed a bimodal curve with two knee valgus angle
peaks [4]. However, the two knee valgus angle peaks were not com-
pared, although a single value for the maximum knee valgus angle of fe-
male athletes was presented (14.2± 5.2°). In the present study, we
divided sidestep cutting stance time into stop and side-movement
phases and demonstrated that the mean knee valgus angle peak during
the stop phase was 11.7°, which was greater than the 9.1° found during
the side-movement phase. Nevertheless, these angles were smaller
than those reported in the study by McLean et al.
In this study, three of the 10 subjects presented only one knee val-
gus angle peak. Beaulieu et al. analyzed the changes in knee varus and
valgus angles during sidestep cutting with an approach speed of
4.05.0 m/s and similarly showed that only one knee valgus angle
peak (15.3±8.8°) was formed in female athletes [22]. The maximum
knee valgus angle for the non-dominant side of females during land-
ing had been previously reported to be 12.5 ±2.8° [5]. In the present
study, the mean knee valgus angle peak during the stop phase for the
subjects who exhibited only one knee valgus angle peak was 19.5 ±
10.3°, which was 4.25.3° greater than that reported previously.
Fig. 2. Temporarychanges of the knee varusand valgus anglesfor 10 subjects duringside-
step cutting. It is a bimodality curve with two valgus angle peaks. The rst valgus angle
peak was observed 79.6± 38.2 ms after foot striking during the stop phase. The second
peak was observed 170.6± 33.7 ms after foot striking during the side-movement phase.
Table 1
The comparison of knee valgus angle peak, quadriceps muscle activity, hamstring mus-
cle activity, and H/Q ratio between the stop and side-movement phases.
Variable Stop phase Side-movement
phase
p Effect size (r)
Knee valgus angle peak
(°)
11.7± 7.5 9.1 ±3.5 0.58 0.18
Quadriceps muscle
activation (%)
171.5± 50.0 69.9 ±50.1 b0.0010.83
Hamstring muscle
activation (%)
59.5± 28.3 53.0 ±35.7 0.66 0.15
H/Q 0.32± 0.13 0.89 ±0.07 b0.0010.97
H/Q: The ratio of hamstring to quadriceps muscle activation.
Signicant difference between the stop and side-movement phases (p b0.05).
Fig. 3. Temporary changes of the knee valgus angles during sidestep cutting for the
three subjects. The mean knee valgus angle peak was observed 128.2 ±29.1 ms after
distal foot striking during the stop phase.
87D. Xie et al. / The Knee 20 (2013) 8589
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McLean et al. [4] reported that the increased knee valgus angle
found in female athletes during sidestep cutting maneuvers is the
dominant risk factor for ACL injury. A previous study indicated that
ACL injuries occurred when the knee valgus angle was 520° during
sidestep cutting [23]. The possibility of ACL injuries may be increased
during the stop phase because the knee valgus angle peaks during the
stop phase tend to be greater than those during the side-movement
phase. In fact, valgus restriction of the knee during sports maneuvers
can be expected to reduce the strain on the ACL [24], ultimately re-
ducing the number of non-contact ACL injuries [6]. Interestingly, in
this study, the subjects with two knee valgus angle peaks rst landed
on their heels. On the other hand, subjects with only one knee valgus
angle peak rst landed on the distal foot (Fig. 4). However, the two
landing techniques were not compared because of the small number
of subjects in each group. The relationship between knee joint move-
ment and the two different types of landing (heel versus distal foot)
should be monitored and analyzed carefully in the future.
A previous study revealed that the H/Q ratio of female athletes
was 0.250.28 during jump landing [7]. In the present study, the av-
erage H/Q ratio of the stop phase was 0.32±0.13, similar to that
reported previously. In addition, a previous study [9] demonstrated
that the H/Q ratio was the lowest when the knee exion angle was
33°. At that angle, the quadriceps muscle activity was greater than
that of the hamstrings by about 80% MVC. We assumed that any mus-
cle activity of the quadriceps exceeding that of the hamstrings by 80%
MVC was a risk factor for ACL injury during sidestep cutting. In this
study, the muscle activity of the quadriceps was 112% MVC higher
than that of the hamstrings during the stop phase, which supports
our hypothesis. The low muscle activity of the hamstrings during
the stop phase may be insufcient to prevent anterior tibial transla-
tion, resulting in an increased risk of ACL injury.
Krosshaug et al. [11] demonstrated that the estimated time of ACL
injury, based on the group median, ranged from 17 to 50 ms after ini-
tial ground contact. A previous study reported that ACL injuries occur
during the early stage of the deceleration phase of sidestep cutting
cycle [2]. The early stage of the deceleration phase was dened as
the rst 20% of the period from the initial contact of the foot to toeing
offthe stage when the knee exion angle is less than 40°. In the
present study, the early stage of the deceleration phase during side-
step cutting was the period from the initial contact of the foot to
57 ms after foot striking, at which time the knee exion angle was
52.8° and the knee valgus angle was 6.6°. In addition, ACL injuries
were demonstrated to occur most commonly approximately 50 ms
after foot striking during landing in a simulation study [25]. Koga et
al. [26] reported that all the handball and basketball players had im-
mediate valgus motion within 40 ms after initial ground contact.
Bencke et al. [27] found that the activity of the knee extensors peaked
at approximately 46 ms after toe contact, while the knee exors
showed a minimum EMG activity during sidestep cutting. The nd-
ings of the present study substantiates previous research [2,11,26]
that the early stage of the deceleration phase of sidestep cutting is as-
sociated with the greatest risk for ACL injury.
Certain limitations of this study should be addressed. First, 10 fe-
male participants were recruited and included in the analysis. The
Fig. 4. The different sidestep cutting maneuvers that create two valgus peaks (above) or only one valgus peak (below). The gure shows the maneuvers for the heel landing rst (A)
and the distal foot landing rst (B).
88 D. Xie et al. / The Knee 20 (2013) 8589
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small size of this group may have reduced the statistical power of the
ndings. A more consistent and universal epidemiological study with
a large number of participants should be conducted in the future. Sec-
ond, the present study is an experimental study and does not complete-
ly simulate the actual sidestep cutting maneuver in real life basketball
competitions. Analysis of the aspects inuencing sidestep cutting,
such as speed and direction of cutting, is necessary. Finally, the present
study only analyzed the non-dominant leg. A previous study reported
that the knee valgus angle peak of the dominant leg in female athletes
is signicantly greater than that of the non-dominantleg during landing
[5]. We plan to examine the differences of the maximum knee valgus
angles and muscle activity of the non-dominant as well as the dominant
leg during sidestep cutting maneuvers in future studies.
5. Conclusion
The authors analyzed 90° sidestep cutting maneuvers for female
basketball players and discovered that the temporary changes in the
knee valgus and varus angles may present two valgus angle peaks
or only one peak. The knee valgus angle peak during the stop phase
tended to be greater than that during the side-movement phase. On
the contrary, the H/Q ratio during the stop phase was signicantly
lower than that during the side-movement phase. We concluded
that female basketball athletes have a higher risk of ACL injury during
the stop phase of sidestep cutting as compared to the side-movement
phase. In order to prevent ACL injury, there is a need to train ham-
string muscles, and knee valgus should be avoided, especially during
the stop phase of sidestep cutting.
Conict of interest
None of the authors reports any conict of interest.
Acknowledgments
No sponsor supported this study.
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... Olsen et al, 96 stated "the sequence of events leading to a right-sided ACL injury included (i) the subject takes two steps with the ball and (ii) pushes off to prepare for a sidestep cutting at high speed." A study by Xie et al, 97 examined the phases of a high speed sidestep cutting maneuver that puts basketball athletes at an increased risk for ACL injuries. ...
... Ten healthy collegiate female basketball athletes were instructed to run two steps In addition, bipolar superficial EMG sensors were used to measure the maximum voluntary isometric contraction against five seconds of manual resistance of the vastus lateral, vastus medial, biceps femoris, and semimembranous muscles on each subject's non-dominant leg. 97 The sidestep cutting stance time was divided into stop and side-movement phases. The mean knee valgus angle peak during the stop phase was 11.7 degrees while during the side-movement phase the peak angle was 9.1 degrees. ...
... The possibility of ACL injuries may be increased during the stop phase because the knee valgus angles peaks during the stop phase and tend to be greater than those during the side-movement phase. 97 Xie et al, 97 concluded that in order to prevent ACL injuries in women's basketball there is a need to train hamstring muscles and avoid knee valgus during the stop phase of a sidestep cutting maneuver. ...
Article
This study investigated differences in movement technique and ankle range of motion in female collegiate basketball, soccer, and volleyball athletes and the potential need to customize injury prevention programs athletes based on sport-based differences. Forty-five collegiate female athletes volunteered to participate in this study (age=20 ± 2 years, mass=68.7 ±11.1kg, height=171.6 ±9.4cm). Athletes were members of a university basketball, soccer, or volleyball team. Ankle dorsiflexion range of motion was measured in non-weight bearing in knee extension, non-weight bearing in knee flexion, and weight bearing lunge test. A jump-landing task was scored using the Landing Error Scoring System (LESS) was also performed. We did not observe a significant difference between sports for the composite LESS score (P> 0.05). A greater proportion of basketball participants exhibited the “knee flexion at initial contact” error than the two other sports (P=0.043). There were no significant differences between ACL or ankle injury history and LESS score or ankle ROM (P>0.05). Participants with less than five degrees of NWB-KF ankle dorsiflexion had significantly higher LESS scores (P=0.001). Twenty-two of forty-five participants exhibited with high injury risk scores, as measured by the Landing Error Scoring System. The findings reveal an association between less ankle dorsiflexion and poor lower body movement patterns. These results indicate the potential importance of incorporating ankle mobility exercises in training programs for collegiate female athletes to decrease the incidence of lower extremity injury.
... High-risk match movements in these types of sports are side-cuts and change-of-direction manoeuvres [1]. One of these movements is the stop phase, which bears the highest risk of ACL injury of all side-cutting phases [32]. Therefore, clinical tools are needed to identify potential risk factors as well as athletes at high risk of sustaining a severe knee injury. ...
... Because the plates on the SpeedCourt ® are randomly highlighted on the screen, the direction of the next action is not anticipated [13]. The stop phase bears the highest risk of ACL injury of all side-cutting phases [32]. This study showed that the contact times of different change-of-direction tests varied among players of different types of sports and age groups. ...
Article
Purpose Side-to-side asymmetry in side-cutting manoeuvres is a known risk factor for severe knee injury. Potential leg asymmetry during ground contact times of different change-of-direction manoeuvres was evaluated in athletes by means of the recently developed SpeedCourt® system. The hypotheses were that ground contact times and the limb symmetry index are affected by age and the type of sports. Methods One-hundred and sixty-five athletes (149 men, 16 women, age 16.5 ± 5.1) of popular team sports such as football, team handball and baseball were assessed by means of three different tests [side-hop, lateral change-of-direction (COD) and diagonal COD] using the SpeedCourt® system. Analysis included the factors age, sex, type of sports, ground contact time, leg symmetry index and limb dominance. Results During lateral but not diagonal COD tests, football players had shorter contact times than players of team handball (p = 0.026) and baseball (p = 0.015) of the same age group. The side-hop tests yielded differences in the leg symmetry index between players < 16 years and players > 16 years (p < 0.01). Mean ground contact time differed in each of the side-hop, lateral COD and diagonal COD tests (143.5 ± 20.0 vs. 256.2 ± 66.1 vs. 320.4 ± 55.0). Contact times and test durations of side-hop, lateral COD and diagonal COD tests were shorter for older players (p < 0.01). Conclusions Ground contact times of side-hop and change-of-direction manoeuvres are influenced by age, the type of sports and limb dominance. Such information is fundamental for future sports medicine research and needs to be considered in pre-season screening or when used as a criterion for return-to-competition of players with previous severe knee injury. Assessment of change-of-direction manoeuvres should be included in future return-to-competition test batteries. Level of evidence III.
... All the 45°, 90° and 135° sidestep cutting conditions ( Figure 2) were anticipated and administered in the biomechanical laboratory. These are the typical cutting angles performed in basketball games (McClay et al., 1994b;Nigg et al., 2009;Schreurs et al., 2017;Xie et al., 2012). A 1.2 m x 1.2 m force platform (Advanced Mechanical Technology Inc, Watertown, USA, sampling at 1000 Hz) and its surrounding were covered with the standard basketball indoor wooden surface to measure the GRFs during cutting tasks. ...
... The braking phase was defined as the weight acceptance phase with the knee power absorption period during side-cutting movement. The braking and propulsion phases were determined by the maximum knee flexion of the cutting leg (Havens & Sigward, 2015a;Lam et al., 2015;Xie et al., 2012). The stance phase of each sidestep cutting condition was identified as the period from initial contact of the foot to take-off determined when the vertical GRF first exceeded and went below 10 N (Lam et al., 2017). ...
Article
This study examined the effects of shear reduction shoes on braking and propulsion ground reaction forces (GRFs), free moments, and joint moments when cutting towards different directions. Fifteen male university basketball players performed sidestep cutting towards 45°, 90° and 135° directions with maximum-effort in shear reduction and control shoes. Two-way (angle x shoe) ANOVAs with repeated measures were performed to determine the interaction and main effects of cutting angle and shoe for all tested variables. Results showed that cutting angles had significant influence on most of the variables, except for the peak-free moment, peak ankle eversion moment and maximum loading rate of resultant shear GRF. The shear reduction shoes significantly delayed the timing to the first peaks of vertical and resultant shear GRFs compared with the control shoes. During propulsion, the shear reduction shoes generated smaller peak propulsion resultant shear and vertical ground reaction forces. Additionally, the shear reduction shoes did not induce distinct frontal and transverse moments at the ankle and knee joints compared with the control shoes. These results suggest that the application of shear reduction structure could be beneficial to attenuate vertical and shear impact peaks, offering additional insights to reduce shear-related injuries.
... ankle sagittal plane ROM is equivalent to the sum of peak ankle dorsiflexion and plantar flexion angles) during the deceleration phase of the cutting and rebound tasks. The deceleration phase was defined as the time from initial contact to peak knee flexion for both the cutting and rebound tasks, similar to previous research (Klem et al., 2017;Xie, Urabe, Ochiai, Kobayashi, & Maeda, 2013). This phase has been identified as the key time point for lower limb injury to occur due to greater peak knee joint loading (Burnham et al., 2010;McKay et al., 2001b;Xie et al., 2013). ...
... The deceleration phase was defined as the time from initial contact to peak knee flexion for both the cutting and rebound tasks, similar to previous research (Klem et al., 2017;Xie, Urabe, Ochiai, Kobayashi, & Maeda, 2013). This phase has been identified as the key time point for lower limb injury to occur due to greater peak knee joint loading (Burnham et al., 2010;McKay et al., 2001b;Xie et al., 2013). ...
Article
Objective The aim of this study was to investigate the effects of ankle taping on ankle and knee joint biomechanics during cutting and rebound activities in females. Design Cross-sectional. Setting Laboratory. Participants Twenty semi-professional female basketball players performed a cut and rebound task under two conditions (taped and no-tape). Main Outcome Measures Kinematic and ground reaction force data were collected during the deceleration phase of each movement task. Results Taping resulted in a significant reduction in peak ankle dorsiflexion, inversion and internal rotation angles and range of motion (ROM) at the ankle joint; and reduced knee ROM in the sagittal plane during the rebound task only. Taping significantly reduced peak knee flexion moment (0.29 Nm/kg, P = 0.013) and increased knee internal rotation moment (0.63 Nm/kg, P = 0.026) during the cutting task compared to control. Taping also significantly reduced the internal rotation moment (0.07 Nm/kg, P = 0.025), and medial shear forces (0.14 N/kg, P = 0.012) in the rebound task. Conclusion Results of the study suggest that ankle taping restrict ankle range of movement in the rebound task only and ankle taping appears to have upstream effects on the knee, which may have injury implications.
... ankle sagittal plane ROM is equivalent to the sum of peak ankle dorsiflexion and plantar flexion angles) during the deceleration phase of the cutting and rebound tasks. The deceleration phase was defined as the time from initial contact to peak knee flexion for both the cutting and rebound tasks, similar to previous research (Klem et al., 2017;Xie, Urabe, Ochiai, Kobayashi, & Maeda, 2013). This phase has been identified as the key time point for lower limb injury to occur due to greater peak knee joint loading (Burnham et al., 2010;McKay et al., 2001b;Xie et al., 2013). ...
... The deceleration phase was defined as the time from initial contact to peak knee flexion for both the cutting and rebound tasks, similar to previous research (Klem et al., 2017;Xie, Urabe, Ochiai, Kobayashi, & Maeda, 2013). This phase has been identified as the key time point for lower limb injury to occur due to greater peak knee joint loading (Burnham et al., 2010;McKay et al., 2001b;Xie et al., 2013). ...
... The lack of kinematic data limited the scope of the analysis of the current study. Traditionally, peak knee flexion angle is used to define the deceleration and propulsive phase of a change of direction task (Xie et al., 2013). Therefore, by defining the deceleration and propulsive phase by anteroposterior GRF, participants may not have been at peak knee flexion concurrently with peak anteroposterior GRF. ...
Article
This study explored the effects of no braces, softshell (AE), and semi-rigid (T1) ankle braces on time to complete a modified agility task, as well as lower extremity muscle activity and impulse during the change of direction component of the task. Thirty-nine healthy, active individuals completed a modified agility task under the three brace conditions. Time to complete the modified agility task, along with mean surface electromyographic activity (sEMG) and impulse during the deceleration and propulsive phases of the task were measured. There were no significant differences across conditions with respect to sEMG or impulse measures during the deceleration or propulsive phases. There was a significant change in time to complete the modified agility task, F(2,76) = 17.242, p< 0.001, ηp² = 0.312. Post-hoc analysis revealed a significant increase in time to complete the modified agility task when wearing the AE (0.16 (95% CI, 0.062 to 0.265) seconds, p< 0.001) and T1 (0.20 (95% CI, 0.113 to 0.286) seconds, p< 0.001) ankle braces compared to no braces. It appears that performance on a modified agility task may be diminished when wearing ankle braces, although sEMG activity and impulse are unaffected.
... The nature of side cutting maneuvers is influenced by various factors, such as run up 9 , foot placement, 10 weight acceptance, 11,12 change of direction, 13 and push off characteristics. 1,2 Biomechanical studies usually focus on the ground contact phase, which can be divided into two main parts: weight acceptance and push off. ...
Article
Full-text available
This study examined the influence of basketball shoe midsole inserts with different forefoot and rearfoot rebound properties on biomechanical loading and subjective perception during a side-cutting maneuver. Eleven male basketball players executed side cutting in four shoe conditions mechanically characterized for their rearfoot/forefoot rebound: compliant/compliant, springy/springy, compliant/springy, and springy/compliant. Lower extremity kinetics and kinematics (normalized to body mass), as well as subjective perception, were measured. During the weight-acceptance phase, there were no differences between shoes in all biomechanical variables, except a slightly greater ankle range of motion (1.2° greater than the other three shoes) in the frontal plane for shoe compliant/springy. During the push-off phase, shoe springy/springy led to a greater ankle plantarflexion moment (1.21 Nm/kg greater than the other three shoes, p < 0.001) and knee internal rotation moment (0.09 Nm/kg greater than the other three shoes, p = 0.012), while shoe compliant/springy resulted in a greater ankle range of motion in the frontal plane (1.4° greater than the other three shoes, p < 0.001). Perception data showed no statistically significant difference among any shoes. In conclusion, springy inserts of basketball shoe midsoles induced a biomechanical loading effect. Perception of players being unaffected indicates the importance of biomechanical evaluation to examine the effects of the given shoe modifications during side cutting.
... 5,6,7 Side cutting is also a commonly used task to evaluate sports-related products such as footwear, 8,9 compression shorts, 10 and ankle support braces. 11 When conducting side cutting experiments in the laboratory, factors such as cut angle 12,13 and approach speed 14,15 were often well controlled as they can alter the resulting kinematics and/or kinetics. In some protocols, arrows or light signals were set to simulate proactive and reactive conditions in sports, 5,12,16 and these modifications have resulted in different postures and knee moments. ...
Article
Full-text available
This study examined the effectiveness of floor markings for controlling cut width during the analysis of side cutting maneuvers. Eleven male basketball players performed two side cutting maneuvers of narrow (30 cm) and wide (45 cm) cut width and were guided by floor markings. Ground reaction forces, together with ankle, knee, and hip joint ranges of motion (ROM), and respective joint moments were determined. Cut widths were verified by two approaches by calculating the actual foot-to-foot and foot-to-pelvis distances from motion data. Biomechanical lower extremity loading showed no significant differences in most kinetic and kinematic variables between narrow and wide cuts. The difference in foot-to-foot distance (15.1 [11.6, 18.7] cm, p < 0.001) between conditions corresponded well with floor markings, however, the difference in foot-to-pelvis distance was much smaller (2.3 [0.3, 4.4] cm, p = 0.030). It is concluded that floor markings are not sufficient for controlling the actual anatomical cut width in laboratory experiments. Participants may adjust their body postures to maintain similar lower extremity loading when performing side cuts differing in foot placement width. Cut width should be represented by foot-to-pelvis distance and not foot-to-foot distance.
Article
Cutting is considered a “high-risk” movement for anterior cruciate ligament (ACL) injuries. It has been established that sex differences exist during cutting, placing females at greater ACL injury risk. Foot progression angle (FPA) during landing has been shown to influence lower extremity mechanics, yet little is known how FPA influences mechanics during cutting. The purpose of this study was to compare two FPA conditions during cutting between males and females. Twenty-four males and females were tested using two FPA conditions: toe-in 15˚ (TI15) and toe-out 15˚ (TO15). Right knee joint kinematic and kinetic variables were measured using a motion capture system and force plate. Five successful trials were collected and compared between FPA conditions. One-dimensional statistical parametric mapping was used to assess changes in knee mechanics between males and females over the entire stance phase. The only sex×FPA effect found was knee flexion angle. Females cutting at TI15 had decreased knee flexion angle compared TO15 (p=0.019). Significant sex main effects included knee abduction and rotation angles, and knee flexion and rotation moments. Significant FPA main effects included knee flexion, abduction and rotation angles. The results show cutting with a toe-in FPA of 15° is enough to induce changes in knee abduction angle while cutting with 15° toe-out FPA influenced knee flexion and rotation angles. These data suggest that different cutting FPAs may be influential on known ACL injury risk variables. However, more research is warranted on cutting FPA before FPA is targeted as part of ACL injury prevention protocols.
Technical Report
Through analyzing video data of human actions, various kinematic information, such as the trajectory, velocity, and acceleration of a given movement, can be obtained. Several types of computer software specifically designed for analyzing human actions have been developed in the past decade. In the present study, we investigated the reliability and validity of two kinds of picked up well-known motion analysis software. For this purpose, the functions of “Kinovea” (open-source software) were compared to those of the “Dartfish Software” (Dartfish). The coordinates (x, y) acquired from the analysis showed no significant differences [p > 0.05] and a high correlation in each coordinate [r > 0.97] between these two kinds of software. We also tested two subjects (1st and 2nd authors) whether individual differences influence the identification of tracing markers placed on the actor’s body on video. The results showed no individual differences between the data of the coordinates in each software [p > 0.05]. Our findings therefore suggest that Kinovea has a high reliability and validity that is comparable to the Dartfish Software. Kinovea can be a useful tool for analyzing kinematics of human actions.
Article
Full-text available
The objective of this study was to qualitatively characterize quadriceps and hamstring muscle activation as well as to determine knee flexion angle during the eccentric motion of sidestep cutting, cross-cutting, stopping, and landing. Fifteen healthy collegiate and recreational athletes performed the four movements while knee angle and electromyographic activity (surface electrodes) of the vastus lateralis, vastus medialis obliquus, rectus femoris, biceps femoris, and medial hamstring (semimembranosus/semitendinosus) muscles were recorded. The results indicated that there is high-level quadriceps muscle activation beginning just before foot strike and peaking in mid-eccentric motion. In these maneuvers, the level of quadriceps muscle activation exceeded that seen in a maximum isometric contraction. Hamstring muscle activation was sub-maximal at and after foot strike. The maximum quadriceps muscle activation for all maneuvers was 161% maximum voluntary contraction, while minimum hamstring muscle activity was 14%. Foot strike occurred at an average of 22° of knee flexion for all maneuvers. This low level of hamstring muscle activity and low angle of knee flexion at foot strike and during eccentric contraction, coupled with forces generated by the quadriceps muscles at the knee, could produce significant anterior displacement of the tibia, which may play a role in anterior cruciate ligament injury.
Chapter
The rehabiliation of knee injuries involving the anterior cruciate ligament (ACL) is controversial. This paper describes strain in the normal and reconstructed ACL during a series of passive and active tests of knee flexion with and without varus, valgus and axial rotation torques on the tibia.
Article
The Standardization and Terminology Committee (STC) of the International Society of Biomechanics (ISB) proposes a general reporting standard for joint kinematics based on the Joint Coordinate System (JCS), first proposed by Grood and Suntay for the knee joint in 1983 (J. Biomech. Eng. 105 (1983) 136). There is currently a lack of standard for reporting joint motion in the field of biomechanics for human movement, and the JCS as proposed by Grood and Suntay has the advantage of reporting joint motions in clinically relevant terms.In this communication, the STC proposes definitions of JCS for the ankle, hip, and spine. Definitions for other joints (such as shoulder, elbow, hand and wrist, temporomandibular joint (TMJ), and whole body) will be reported in later parts of the series. The STC is publishing these recommendations so as to encourage their use, to stimulate feedback and discussion, and to facilitate further revisions.For each joint, a standard for the local axis system in each articulating bone is generated. These axes then standardize the JCS. Adopting these standards will lead to better communication among researchers and clinicians.
Article
Background: Women have higher non-contact anterior cruciate ligament injury rate than men do in sport activities. Non-contact anterior cruciate ligament injuries frequently occur in sports requiring cutting tasks. Alternated motor control strategies have identified as a potential risk factor for the non-contact anterior cruciate ligament injuries. The purpose of this study was to compare the patterns of knee kinematics and electromyographic activities in running, side-cutting, and cross-cutting between men and women recreational athletes. Methods: Three-dimensional kinematic data of the knee and electromyographic data of selected muscles across the knee joint were collected for 11 men and 9 women recreational athletes in running, side-cutting, and cross-cutting. Regression analyses with dummy variables for comparison of knee motion patterns between men and women. Results: Women tend to have less knee flexion angles, more knee valgus angles, greater quadriceps activation, and lower hamstring activation in comparison to men during the stance phase of each of the three athletic tasks. Literatures suggest these alternated knee motion patterns of women tend to increase the load on the anterior cruciate ligament. Conclusion: Women on average may have certain motor control strategies that may alter their knee motion patterns. Women's altered knee motion patterns may tend to increase the load on the anterior cruciate ligament in the selected athletic tasks, which may contribute to the increased anterior cruciate ligament injury rate among women. Relevance: Non-contact anterior cruciate ligament injuries frequently occur in sports. Altered motor control strategies and lower extremity motion patterns are likely to play an important role in non-contact anterior cruciate ligament injuries. Non-contact anterior cruciate ligament injuries may be prevented by correcting altered motor control strategies and associated lower extremity motion patterns through certain training programs.
Article
Based on the spline software of Lyche et al., a subroutine package is presented in which the amount of smoothing on a set of n noisy datapoints is determined from the data by means of the Generalized Cross-Validation (GCV) or predicted Mean-Squared Error (MSE) criteria of Wahba and her collaborators. Following an idea of Hutchinson and de Hoog, an efficient O (m2n) algorithm is used for calculating the criterion functions, where 2m is the order of the spline function. In this fashion, earlier O (n3) approaches based on the singular value decomposition can be avoided.