Stiff versus soft landings and other considerations when programming drop landings with athletes

Landing from heights is an integral skill for participating in sports. Athletes land from various heights in many sports, and sustaining high impact forces during intensive and repetitive landings has a close relationship to lower limb injuries such as sprains and fractures ^[1,4]. The peak impact force upon landing can range from 3-7 times the individual’s body weight – and sometimes even higher – depending on the drop height, landing technique and surface ^[8,19]. 

Practitioners often prescribe the drop landing exercise as part of the warm up and training program to impart proper landing technique to athletes. Drop landing is also often used to increase lower limb strength. Practitioners need to understand the biomechanical variables and the factors that influence them if they want their athletes to achieve the desired adaptations from the drop landing. 

This article will discuss how changes in drop height, landing technique, single vs. double leg, and gender differences affect the biomechanics of drop landing, and provide some considerations for incorporating drop landing into strength training.

Energy dissipation by the musculotendinous unit

During landing, the musculotendinous unit (MTU) lengthens to absorb the impact force and dissipate energy. Interestingly, the tendon stretching is the source of the initial lengthening of the MTU, while the muscles remain in an isometric contraction ^[16]. This facilitates the tendon storing elastic energy, which can lead to a forceful recoil and increased propulsion force if the landing is quickly followed by a jump. However, if there is no jump, the lengthening of the muscle fibres will dissipate the strain energy on the tendon ^[16].

The amount of impact force sustained during landing depends on the drop height, with higher drop height resulting in greater impact ^[17]. Higher drops not only impart greater impact forces but  lead to greater joint range of movement and longer ground contact duration, both in response to the greater amount of energy that needs to be dissipated ^[17]. Dropping from greater heights unsurprisingly increases the risk of injury, especially when individuals do not have proper landing mechanics or sufficient muscular strength to absorb the impact force. That said, raising the drop height can also be a way of increasing training intensity to induce a greater level of adaptations, as individuals would have to generate more force to counter the impact.

Practitioners may use 90-100% of the athlete’s countermovement jump height as a reference when selecting the height for the athlete’s drop.

Soft vs. stiff landing

The kinematics and muscle action differ when performing a soft vs. a stiff landing. Soft landings involve large ankle, knee and hip flexion; while stiff landings have a small range of motion at these joints (video 1a and 1b).

One study that had female team sports athletes drop from a 59 cm platform found that peak impact force occurred at the same time (50 ms) with both landings, but the magnitude of the peak impact force was significantly greater during the stiff landing than the soft (~32 N/kg bodyweight vs. ~23 N/kg bodyweight)^[5].

Stiff landings, therefore, have similar implications as dropping from greater heights: a higher risk of injury if the athlete lacks proper landing mechanics or sufficient muscular strength. But, again, it could also mean greater adaptations for the musculotendinous system if the mechanical and strength requirements are met. Because the muscles must produce high amounts of force rapidly to counter the impact force in order to maintain and upright position, stiff landings, in particular, are an effective method for training the rate of force development.

The same study also reported differences in the amount of work performed by the hip, knee and ankle joints during each landing type: 25%, 37% and 37%, respectively, during the soft landing and 20%, 31% and 50%, respectively, during stiff landing.

This indicates changing the landing strategy would likely lead to different magnitudes of adaptation at MTUs across the hip, knee and ankle.

It is worth noting that while the hip and knee may bear a greater relative workload during soft compared to stiff landing, the absolute workload on these joints may still be higher during a stiff landing due to the greater impact force. Additionally, stiff landings from a low height may still result in greater impact force, but there is likely minimal difference in workload distribution across the joints during soft landings from low height ^[17]. Finally, the greater impact forces of stiff landing place greater strain on ligaments such as the anterior cruciate ligament (ACL) ^[11]. Hence, it is important to start athletes off with soft landings from a given height, and then progress to stiff landings. 

Single vs. double leg landing

In general, single leg landings imposed greater strength and balance demands than double leg landings. Hence, kinematics and muscle activation differ to a certain extent.

Double leg landings entail greater knee and hip flexion, while single leg landings generate greater impact forces ^[6,19]. Like during stiff landings, single leg landings place greater load on MTUs across the ankle joint ^[19]. Athletes can reduce the demand on the MTU by employing a stiffer landing during a single leg landing, because the passive tissue structures can absorb the greater force better than the could during a soft landing ^[20].

Single leg landings produce more knee movement in the frontal plane ^[19]. In order to maintain balance during the single leg landing, individuals have to shift the hip centre towards the lateral side of the knee, resulting in a greater hip adduction angle, which places greater demand on the hip abductor muscles. Individuals with weak hip abductors may experience more knee valgus, as a result ^[2]. Practitioners must, therefore, ensure that the athletes are able to first perform a single leg squat without knee valgus before prescribing a single leg drop landing.

As common sports skills such as running, sprinting and change of direction involve individuals supporting themselves on a single leg, practitioners should verify their athletes have the strength and technical competency to perform single leg landings to reduce the risk of lower limb injury.  This points to the role of single leg drop landings as part of an injury reduction strategy.

Gender differences in landing strategy

Non-contact ACL injuries are 3-6 times more frequent in females than males, with muscle strength, dynamic knee valgus, muscle activation patterns, proprioception and neuromuscular control being some of the risk factors ^[15].

Researchers comparing the difference in landing kinematics between males and females have reported conflicting findings ^{[3,7,10,12,14,18]}. For example, one study reported that females have less knee flexion during initial ground contact ^[3], while another reported greater knee flexion during initial ground contact ^[7]. One possible reason for the inconsistent findings could be the studies’ failure to account for individual strength level, i.e., both male and female participants had to perform the drop landing from the same height. To avoid adding to the confusion, this section will emphasize data from studies that accounted for individual physical capability ^[10,18].

Weinhandl et al. observed that males had greater ranges of hip and knee flexion during both double and single leg landings ^[18]. That indicates that females tend to adopt a stiffer landing technique, even when accounting for relative intensity. Apart from greater impact force, landing with lower knee flexion also increases quadriceps contraction, which may further increase ACL strain, thus increasing injury risk. Furthermore, females had greater quadriceps activity and lower hamstring activity during landing compared to males, suggesting a greater risk to the anterior tibialis in females ^[10].

While females tend to exhibit landing mechanics that put them at higher risk of injury, practitioners should not avoid prescribing drop landings or related exercises. Landing is a necessary skill in most sports, so we need to train and develop movement biomechanics and strength accordingly. Nevertheless, these gender differences highlight the importance of detailed screenings for each athlete to better understand their individual deficits.

Drop landing progression: From squat screening to sport skill scenarios

The gender differences drive home the need to squat properly before an athlete can land properly. Flexion of hip, knee and ankle joints are the leading indicators of proper load distribution among the joints (videos 2a and 2b, while video 2c and 2d show two examples of mechanics to avoid).

Squat screening can help detect the underlying causes of knee valgus during landings, which is one of the major differentiators between men and women and an increased risk factor for females. Common issues include excessive foot pronation and weak gluteus medius. Females’ lower hamstring and higher quadriceps activity during landing may stem from a lack of hip flexion, as shown in video 2d. Again, practitioners can rectify the movement mechanics during the squat training phase.

But bear in mind that the common errors shown in video 2c and 2d may be a function of muscle weakness or lack of joint mobility or movement literacy, irrespective of gender.

Once the athlete is proficient in performing the squat, he or she may then progress to the drop squat with slow deceleration (video 3a), and then to rapid catch (video 3b). Ensure that the athlete is able to replicate a normal squat when performing the drop squat prior to progressing to drop landing. Then, start off with soft landings before progressing to stiff landing.

Because impact force increases with drop height, stiff landings and going from double to single leg landings, practitioners should adjust the training volume to reflect the higher stresses that come along with each progression. I recommend limiting the volume to 3-4 sets and 3-5 repetitions per set.

As mentioned above, soft landings result in a more even load distribution among the lower limb joints, while stiff landings require the ankle joint to absorb more of the impact force. Hence, soft landings are more appropriate during the general training phase to allow for more general adaptation, adjusting the drop height for overloading.

Softer landings also put the athlete through a greater range of movement, which may be more beneficial to objectives during the general training phase (e.g., hypertrophy). As the training phase progresses to require more sport specificity and rate of force development work, practitioners may switch to stiff landings.

Integrating drop landings with eccentric and isometric training

Drop landing has several training benefits over simply jumping and landing. First, by eliminating the jump phase and simply focusing on the landing, the athlete has more time to anticipate and co-contract the muscles involved. This is especially important when teaching the landing mechanics.

Second, regardless of the landing strategy (soft or stiff), drop landing may be used as a method for eccentric overload training. During jumping and landing, the athlete’s jumping ability necessarily limits the maximum eccentric loading on the landing. With drop landing, practitioners can adjust the height to suit the athlete’s training status, including exposing them to higher eccentric loading than they could create on their own via a jump.

Once the athlete is proficient at performing the drop landing, practitioners may then progress to more advanced activities such as a drop jump (video 4a), or include some form of perturbation upon landing (video 4b). Practitioners can also modify the drop landing by including other activities that are relevant to game scenarios. For example, performing a change of direction activity immediately upon landing, or performing a drop jump to catch a rebound ball.

In my previous article, “Combining plyometrics and isometric training to improve tendon stiffness and performance,” I recommended pairing isometric and plyometric exercises with similar biomechanics for contrast training. This optimizes musculotendinous stiffness adaptation. Practitioners may pair isometric squats with drop landings as part of their contrast training sets. However, since one of the main features of the isometric squat is inducing postactivation performance enhancement of a subsequent jump, a drop jump instead of a drop landing may be a better pairing with the isometric squat to maximise the training effect.