Modifying an athlete’s change of direction mechanics by addressing biomechanical and neuromuscular deficits associated with hazardous knee joint loading is an effective strategy to reduce anterior cruciate ligament loading. This can be achieved through biomechanical and neuromuscular informed training interventions. |
Balance training is a potentially effective strategy to reduce knee joint loads during cutting, most likely attributed to eliciting safer knee agonist-antagonist muscle patterns and hip and trunk muscle activity. Further research is necessary in greater sample sizes and acknowledging measurement error when interpreting findings, to definitively confirm the efficacy of this method. |
Change of direction technique modifications that focus on reducing lateral trunk flexion, reducing lateral foot plant distances, increasing knee flexion, and promoting earlier braking (during the penultimate foot contact), provide an effective training modality for reducing COD knee joint loading. However, in order to confirm the efficacy and adherence of this method, studies can be improved by including a control group, investigating larger sample sizes, acknowledging measurement error when interpreting findings, and considering the performance implications. |
1 Introduction
2 Literature Search Methodology
-
Change of direction technique modification training: COD drills performed with coach feedback and cues that focus on modifying COD technique, such as lateral foot plant distance/ trunk positioning.
-
COD speed and footwork training: pre-planned COD drills with no coach feedback and cues regarding COD technique.
-
Balance training: balance training that incorporates stable and unstable training methods, such as balancing on one leg (while catching a ball), wobble boards, etc.
-
Mixed training programmes: sessions that integrate exercises from at least three or more of the following training modalities: plyometrics, stretching, balance, trunk stabilisation and/or resistance training. These involve dedicated sessions performed outside typical sports-specific practice and games.
-
Resistance training: sessions that include free weight and/or machine-based resistance training.
-
Perturbation-enhanced plyometrics: plyometric training performed with added perturbation (motorised platform) over weight acceptance.
-
Trunk stabilisation training or dynamic core stability training: trunk stabilisation training refers to training with static exercises (i.e. planks, etc.). Dynamic core stability training includes exercises performed dynamically (i.e. dynamic planks, bridges, etc.) with added perturbations.
-
Combined training: training that combines two of the abovementioned training modalities. These are sub-divided into: combined COD technique modification and balance training, combined trunk stabilisation and resistance training, and combined resistance training and intersegmental control training during running and COD drills.
-
Warm-up interventions: neuromuscular warm-up interventions that were typically performed 15–25 minutes prior to sport-specific practice (i.e. technical and tactical) and/or games. These warm-ups replaced their normal skill/tactical warm-up, and include exercises from various training modalities, such as trunk stabilisation, plyometrics, balance, body weight resistance training, running and COD drills. These include the Oslo Neuromuscular warm-up, core position and control (Core-Pac) warm-up intervention, and FIFA’s Medical Assessment and Research Centre 11+ (F-MARC 11+) soccer-specific injury-prevention warm-up.
3 Results
Study | Subjects | Training intervention | COD task | Results (post-intervention) | Comments |
---|---|---|---|---|---|
COD technique modification drills | |||||
Dempsey et al. [22] | Twelve male non-elite team sport (6 Australian football, 5 rugby union, and 1 soccer) athletes *3 withdrawals | 6-week COD technique modification 2 × a week (15-min sessions) With immediate feedback (visual and oral) | 45° ± 5° side-step. PP and UP ~5 m.s−1 | At IC: ↓ lateral foot plant distance (p = 0.039) PP (ES = 0.55), UP (ES = 0.58) ↓ lateral trunk flexion (p = 0.005) PP (ES = 1.09), UP (ES = 0.14) At WA: ↓ peak KAM (p = 0.034) PP (ES = 0.58) and UP (ES = 0.78) Both postural changes were correlated with the change in KAM change in lateral foot plant distance (r = –0.468, p = 0.025) lateral trunk flexion (r = − 0.377, p = 0.135) ↔ in approach speed, knee flexion IC, and torso rotation | No CG Did not establish reliability, measurement error, or meaningful difference Implications on performance unclear Controlled approach velocity |
Jones et al. [56] | Ten female netball players | 6-week COD technique modification 2 × a week Technique drills that encouraged PFC braking, backwards trunk inclination, and neutral foot position. Weeks: 1 and 2—deceleration emphasis; 3 and 4—randomly with greater entry velocity; 5 and 6—drills performed randomly at speed unanticipated stimulus | 180° turn –PP ~3 m.s−1 | ↓ completion time (p < 0.05, ES = 0.74) ↓ peak KAM (p < 0.001, ES = 0.73) ↓ initial foot progression angle (p < 0.001, ES = 2.60) ↓ initial trunk angle at FFC (p < 0.05, ES = 0.58) ↔ in approach velocity or horizontal GRF ratio (ES = 0.10–0.15) Changes in initial foot progression angle and KAM (r2 = 37%, p = 0.028) | Athletes were not fast to begin with No CG Did not establish reliability, measurement error, or meaningful difference Conference proceeding format |
Change of direction speed and footwork | |||||
Wilderman et al. [57] | 30 female basketball players | 6-week agility (COD speed, footwork, and manoeuvrability drills)—4 × a week (N = 15) plus a CG (N = 15) | 45° side-step Sidesteps—PP 3.3–4.3 m.s−1 | ↑ medial hamstring EMG activation for IG (ES = 0.94) ↔ in knee flexion angle and vertical GRF (p > 0.05, ES ≤ 0.15) | Lack of feedback regarding COD technique Absence of specific side-stepping drills |
Study | Subjects | Training intervention | COD task | Results (post-intervention) | Comments |
---|---|---|---|---|---|
Balance training | |||||
Oliveira et al. [67] | 26 healthy men—recreational athletes | 6-week balance training—4 × a week (30 mins) (n = 13) plus a CG (n = 13) | 90° cut and 1 unexpected perturbed cut (10 cm translation) ~ 2.5 m.s−1 | Balance group during perturbed cutting ↓ peak KAMs (33 ± 25%, p < 0.03, η2 = 0.487) ↑ activation of trunk and proximal hip muscles ↑ burst duration prior (23 ± 11%) to landing (p < 0.02, η2 = 0.798) ↔ changes in peak force, approach and exit velocity (p < 0.05) | Presents findings for the perturbed trial only, and this was for only 1 trial Low approach velocity |
Cochrane et al. [68] | Fifty male AFL players | Allocated either to a CG or to one of four 12-wk training programs: Machine weights Free weights Balance Machine weights and balances | 30˚ and 60˚ side-step, 30˚ XOC PP and UP and—light delay ~4–4.5 m.s−1 Preferred leg | Balance group ↑ flexor/extensor contraction ratio − 18% ↑ flexor muscle activation ↑ biceps femoris/semimembranosus co-contraction ratio ↓ quadricep activation Strength training ↓ flexor/extensor contraction ratio and ↑ quadricep activation | Implications on performance unclear Controlled approach velocity |
Cochrane et al. [63] | Fifty male AFL players | Allocated either to a CG or to one of four 12-wk training programs: Machine weights Free weights Balance Machine weights and balance | 30˚ and 60˚ side-step, 30˚ XOC PP and UP and—light delay ~4–4.5 m.s−1 Preferred leg | Change in moments across WA in all manoeuvres (Mean and SD not provided, thus ES cannot be calculated): Balance ↓ peak KAM (p < 0.001, 62%) and ↓ peak IRM (p < 0.001, 32%) in all manoeuvres Free weights ↔ peak KAM and IRM Machine Weights ↓ peak KAM (p < 0.05, 27%) Machine weights + balance training ↔ peak KAM and IRM CG ↑ peak KAM (p < 0.05, 26%) | Did not establish reliability, measurement error or meaningful difference Implications on performance unclear Controlled approach velocity |
Dynamic core stability training | |||||
Whyte et al. [66] | 31 male varsity footballers | 6-week dynamic trunk control/core stability programme—3 × a week (n = 15) plus a CG (n = 16) | 45° side-step PP and UP | IG ↑ internal hip extensor moment (p = 0.017, η2 = 0.079,24–28% of stance) for PP ↓ internal knee varus moment (p = 0.026, η2 = 0.076, 18– 25% of stance) for PP ↓ knee external rotator moment (p = 0.041, η2 = 0.066, 15– 20% of stance) for PP ↓ posterior GRF for both cuts (p ≤ 0.030, η2 = 0.074–0.081) for PP and UP (11–30% and 15–19% of stance, respectively) ↔ in trunk and pelvic kinematics (Descriptive data not provided, thus ES cannot be calculated) | Use of SPM Contains CG |
Perturbation-enhanced plyometric training | |||||
Weltin et al. [69] | 28 females (soccer, handball, and basketball)* 4 withdrawals: | Perturbation-enhanced plyometric training (PPT) (n = 12): lateral reactive jumps—4-week training—3 times a week Plyometric only—CG (N = 12) | 45° side-step UP—4.0 ± 0.2 m.s−1 | PPT ↓ trunk rotation 7.2° (ES = 1.14), ↓ step width (p = 0.003, ES = 0.88), and ↑ pelvic rotation 4.1° (ES = 0.45) ↓ KAM 0.05 Nm/Kg, CG ↑ 0.14 Nm/kg (SD not provide, thus ES cannot be calculated) ↔ lateral trunk lean (ES = 0.26) | Perturbation-enhanced method is unfeasible to implement in real world as it required motored platform |
Study | Subjects | Training intervention | COD task | Results (post-intervention) | Comments |
---|---|---|---|---|---|
Mixed programme—session that integrates exercises of at least three of the following modalities: trunk, balance, plyometric, strength training, flexibility | |||||
Weir et al. [58] | 10 elite female hockey players | 16-week maintenance training program (3 × 10-min sessions a week) which directly followed a high-dose 9-week initial training intervention (4 × 20-min sessions a week), as part of a biomechanically informed ACL injury prevention program BW plyometric, resistance, and balance exercises | 45˚ side-step—UP | ↓ peak KAMs (ES = 0.30, 26.3%) following maintenance High-risk responders displayed ↓ peak KAM (28.6%) and IRM (37.1%) | Highlight the importance of continuing the training Acknowledged there will be responders and non-responder Abstract format |
Weir et al. [61] | 13 elite female hockey players | 8-week 4 × 15-min multi-component sessions consisting of BW plyometric, resistance, and balance exercises | 45˚ side-step—UP | ↑ TMA of the gluteal (grouped maximus and medius) by 10% during WA (p = 0.006, power = 0.864). ↔ in frontal plane knee moments (p < 0.01, ES = 0.73), ↑ hip extension moment (ES = 0.56) | No differences in frontal plane knee moments Abstract format No CG |
Yang et al. [60] | 22 male, 18 female (basketball and volleyball) | 4-week multi-component programme consisting trunk strengthening, stretching, proprioceptive training, hip extension strength training and plyometric training intervention—3 × a week (N = 18, 9 male and 9 female) Plus a CG (N = 18, 9 male and 9 female) | 45° side-step Sidesteps—PP—5 step run-up | ↔ no differences in knee flexion angles, peak impact posterior GRF, or exit velocities compared to CG following intervention (4–12 weeks post-training intervention) | Multicomponent programme; however, strength exercises were prescribed for, strength/ muscular endurance Considered only limited number of variables—unknown the effect of frontal plane biomechanics Short duration |
Bencke et al. [59] | 17 male handball players | Mixed programme consisting of jump landings, unilateral squats, hamstring pulls, hip abductions, and one-leg coordinated hopping IG (n = 10) 12 weeks twice a week Plus a CG (n = 7) | Side-step (no other decsriptions provided) | IG ↑ VPF (ES = 0.41), ↓ GCTs (p < 0.05, ES = 0.94) due to a ↓ concentric phase duration (p < 0.05, ES = 0.94) ↓ ST (p < 0.05, ES = 0.63) and BF pre-activity duration (p = 0.08, ES = 0.59) | No joint kinetics/kinematics examined |
Staynor et al. [53] | 25 female community-level team sport athletes *6 withdrawals for training group | Split into IG (n = 8) and CG (n = 10), 2 × a week for 9 weeks (15- to 20-min sessions) Combination of BW plyometric, resistance, and balance exercises | Side-step—UP (full details not provided) | IG ↑ peak KFM (ES = 0.77), ↔ in peak KAM (ES = 0.16) and IRM (ES = 0.0), but CG ↑ peak KAM (ES = 0.36, 28%) and ↑ IRM (ES = 0.56, 38%) IG ↓ hip abduction (ES = 0.70, 31%) ↑ knee flexion at foot strike (ES = 0.59, 33%) ↓ trunk flexion range of motion (ES = 0.97, 29%) ↓ lateral trunk flexion (ES = 0.40, 16%) ↓ lateral foot plant distance (ES = 0.84, 11%) | Did not establish reliability, measurement error, or meaningful difference Attendance and compliance rates of 71 ± 14 and 77 ± 7% |
Combined balance and COD technique training | |||||
Donnelly et al. [64] | AFL male athletes (n = 1001) 34 athletes for biomechanical testing (BTT, n = 20; ST, n = 14) | Balance and COD technique training (BTT) or acceleration training (ST) 2 × week—20 min/week—18 weeks 1 × week—weeks 19–28 | 45° ± 5°, side-step Sidesteps—PP and UP | Both training groups: ↓ peak IRM (p = 0.025, ES = 0.57)—45% reduction, during PP ↑ peak KAM (p = 0.022, ES = 0.44)—31% increase during UP | High athlete to coach ratio (40:1) Low athlete compliance (45 ± 22%) |
Combined trunk stabilisation and resistance training | |||||
Jamison et al. [62] | 22 males (previously played American football) N of 10 and 11 completed testing | RT only or Resistance and trunk stabilisation (TS) 6 weeks—3 sessions a week | 45° ± 5°, side-step 3 steps self-selected jog | RT only ↑ peak KAMs (p = 0.012, 50%) and ↑ peak IRM (p = 0.617, 12%) Combined training ↑ peak KAM (p = 0.116, 35%) and ↓ peak IRM (p = 0.110, 35%) (SD not provided, thus ES cannot be calculated) | Did not achieve a priori minimum sample size recommendations Did not establish reliability, measurement error, or meaningful difference Static trunk exercises were used |
Combined resistance training, and intersegmental control training during running and COD drills | |||||
King et al. [65] | 112 athletes with athletic groin pain were assessed pre- and post- rehabilitation | Athletes were subjected to three levels of rehabilitation: Level 1 intersegmental control and strength training Level 2 linear running drills (lumbo-pelvic control and posture) Level 3 multidirectional technique drills that emphasised segmental control (using holding a medball, or arms locked overhead) and lateral propulsion | 110° cut -PP, ~ 2 m.s−1 | ↓ ipsilateral trunk side flexion (ES = 0.79) ↓ hip abduction angle and hip adduction moment ↑ pelvic rotation in the direction of travel (ES = 0.76) ↑ centre of mass translation in the direction of travel relative to centre of pressure (ES = 0.40) ↓ knee flexion angle (ES = 0.33) ↑ ankle plantar flexor moment (ES = 0.48) ↔ in approach velocity (p = 0.434, ES = 0.07) ↓ GCT (ES = 0.30) ↑ dorsi-flexion (ES = 0.58) Large increase in total work done at the ankle, a moderate reduction in the total work done at the hip, and a small reduction at the knee after rehabilitation. | Considered performance implications Showed positive effects for injury risk and performance No CG Did not establish reliability, measurement error, or meaningful difference |
Study | Subjects | Training intervention | COD task | Results (post-intervention) | Comments |
---|---|---|---|---|---|
F-MARC 11+ soccer specific warm-up | |||||
Thompson et al. [70] | 51 females aged 10–12 years soccer players *5 withdrawals | F-MARC 11 + (n = 26) 2 × a week for 7–8 weeks—15 sessions total plus CG (n = 20) | 45° ± 5°, side-step Sidesteps -PP and UP ~ 4 m.s−1 | Bilateral jump (IG) ↓ peak KAM (p = 0.045, ES = 2.15) Side-stepping (IG) ↑ peak KAM PP (p = 0.280, ES = 1.20, 10%) and UP (p = 0.044, ES = 1.98, 18%) | Did not establish reliability, measurement error, or meaningful difference Athlete compliance 70.2 ± 14.0% |
Thompson-Kolaser et al. [71] | 51 preadolescent females (28 intervention, 23 CG)* 5 withdrawals and 43 adolescent (22 intervention, 21 CG)* 6 withdrawals | F MARC 11 + (n = 26) 2 × a week for 7–8 weeks—15 sessions total plus CG (n = 20) | 45° ± 5°, side-step Sidesteps -PP and UP ~ 4 m.s−1 | Preadolescents—PP side-step ↑ precontact flexor-extensor muscle contraction (p = 0.004-0.002) Both groups—side-step ↔ in knee valgus angles or peak KAM—Inspection of graphs indicate ↑ peak KAMs in both groups (Descriptive data not provided so ES cannot be calculated) | Highlights ineffectiveness of intervention for addressing cutting mechanics—only effective for bilateral task Lack of volume and exercises that addresses COD mechanics with feedback, and lack of dynamic trunk exercises |
Oslo neuromuscular injury-prevention warm-up | |||||
Zebis et al. [73] | Elite handball (n = 8) and elite soccer (n = 12) players | Oslo NMS warm intervention—20 min warm up—one season | Side-step (no other decsriptions provided) | ↑ Pre-landing EMG activity ST (p < 0.001, ES = 0.70-0.78) and activity at foot strike (p < 0.05, ES = 0.60) ↔ Quadriceps EMG (ES = 0.10-0.23) ↔ Knee and hip joint angles (ES = 0.11) | Low sample size Investigated low number of biomechanical variables No CG |
Zebis et al. [72] | 40 adolescent female football and handball players | 12 week Oslo NMS warm up—3 × a week (n = 20) plus a CG (n = 20) | Side-step (no other decsriptions provided) | IG ↓ VL-ST activity difference (43%, p < 0.0001) ↑ hamstring MVC (p = 0.0134) ↓ VL EMG preactivity (23%, p < 0.0008), ↑ ST EMG preactivity (18%, p < 0.0001), and ↑ BF EMG preactivity vs CG ↔ peak KAM or knee valgus angle at IC (Descriptive data not provided, thus ES cannot be calculated) | Only frontal plane knee kinetics and kinematics |
Core-Pac warm-up | |||||
Celebrini et al. [75] | Ten adolescent female soccer players | baseline testing—acute changes (n = 10) (move from the centre- lead with the belly button) 4 week—Core-Pac training intervention (n = 7) 4 × week | 15–55° side-step PP and UP | 5 of 7 subjects displayed ↑ knee flexion angle and ↓ peak KAM | Individual differences in response to training intervention No CG |
Celebrini et al. [74] | Twenty adolescent female soccer players | 6 week—Core-Pac training intervention—4 × a week (n = 10) plus a CG (n = 9) | 15–55° side-step PP and UP | IG ↑ knee flexion angle PP cutting (p = 0.001, ES = 2.02) ↔ peak KAM for PP and UP (Raw data not provided, thus ES cannot be calculated) | Low sample size No immediate feedback regarding their technique or biofeedback |