Effect of Adding Mini-squat Exercises at Different Angles to Leg Press Exercise on Quadriceps and Hamstring Strength and H:Q Ratio in Athletes
Phase: NA
Conditions: Exercise
Sponsor: Cairo University

 
 
EFFECT OF ADDING MINI-SQUAT EXERCISES AT 
DIFFERENT ANGLES TO LEG PRESS EXERCISE ON 
QUADRICEPS AND HAMSTRING STRENGTH AND 
H:Q RATIO IN ATHLETES 
 
 
 
 
 
 
 
1-3-2025 
 
 
 
 
 
 
A Protocol Submitted in Partial Fulfillment of The Requirements 
 for the Master’s Degree in Physical Therapy  
for Musculoskeletal Disorders and its Surgery 
Faculty of Physical Therapy 
Cairo University 
2025

 
 

1 
 
CHAPTER I 
INTRODUCTION 
 
Football is a demanding sport requiring a combination of explosive 
strength, speed, and endurance. The nature of the game involves repeated high-
intensity actions, such as sprinting, jumping, tackling, and rapid changes in 
direction, all of which place heavy demands on the lower limbs (Hammami et 
al., 2018). For optimal performance and injury prevention, football players need 
well-developed neuromuscular coordination and muscle strength, particularly in 
the quadriceps, hamstrings, and gluteal muscles (Filho et al., 2023). These 
attributes are often developed through structured strength training programs that 
include both free-weight and machine-based exercises (Wirth et al., 2023). 
Closed kinetic chain (CKC) exercises are movements in which the distal 
segment of the limb remains fixed against a stable surface, causing 
simultaneous motion at multiple joints and promoting integrated muscle 
activation (Pamboris et al., 2024). This configuration enhances joint stability 
through co-contraction of agonist and antagonist muscles, facilitates functional 
movement patterns, and reduces excessive shear forces across joints compared 
to open kinetic chain (OKC) exercises (Ahmed at al., 2023). CKC exercises 
such as the leg press and squat are widely implemented in both rehabilitation 
and performance training due to their capacity to strengthen multiple muscle 
groups, improve neuromuscular coordination, and support functional carryover 
to daily activities and sport-specific tasks (Immanuel & Muthukrishnan, 
2025). 
Mini squats, characterized by shallow knee flexion angles (typically 
between 30°–60°), are commonly integrated in rehabilitation and foundational 
strength programs due to their low mechanical demand on the knee joint and 
their effectiveness in activating the quadriceps without excessive joint strain 

2 
 
(Kubo et al., 2019). They offer a safer alternative to deeper squats, especially 
for individuals with mobility restrictions or those returning from injury (Straub 
& Powers, 2024). However, mini squats alone may not provide sufficient 
mechanical load or range-specific strength adaptations necessary for explosive 
movements like sprinting and vertical jumping, which are essential in football 
(Skratek et al., 2024). 
The leg press exercise complements squat-based training by enabling 
athletes to apply heavy loads to the lower limbs in a more stable, controlled 
environment. This allows for targeted muscle activation without overloading the 
spine or requiring advanced balance and coordination skills. Research has 
shown that the leg press elicits high quadriceps activation and allows for safe 
manipulation of joint angles and foot positioning, making it valuable for both 
strength development and injury prevention (Wirth et al., 2019). When used in 
conjunction with squats, especially mini squats at varying angles, the leg press 
can provide a more complete stimulus to the muscles involved in key football 
movements (Schoenfeld et al., 2017). 
Emerging evidence suggests that combining machine-based and free-
weight resistance exercises produces more comprehensive adaptations than 
either modality alone. For example, Rossi et al. (2018) found that a combined 
squat and leg press training regimen over 10 weeks resulted in improved 
strength, balance, and vertical jump performance. Additionally, Ben Brahim et 
al. (2021) showed that integrating resisted sprinting and strength training 
(including squats and leg presses) enhanced both sprint speed and ball-striking 
power in young elite football players more than soccer training alone. These 
findings support the idea that a multi-modal training approach targeting various 
joint angles and loading patterns may better reflect the complex demands of 
football (Shuzhen et al., 2025). 

3 
 
The hamstring-to-quadriceps (H:Q) ratio is an important indicator of knee 
joint stability, reflecting the balance between knee flexors and extensors. In 
healthy individuals, a conventional H:Q ratio of about 0.5–0.6 is typical, 
whereas elite athletes often display higher ratios due to sport-specific 
adaptations and targeted strength training (Çelebi et al., 2018). Sports involving 
explosive actions, rapid decelerations, and frequent directional changes place 
high demands on both muscle groups, making balanced strength essential for 
performance and injury prevention. Regular monitoring and tailored 
conditioning programs are therefore recommended to enhance performance and 
reduce injury risks (Baroni et al., 2020). 
One critical aspect of lower limb strength balance in football players is 
the (H:Q) ratio, which reflects the relationship between the knee flexor and 
extensor 
muscles. 
A 
low 
H:Q 
ratio, 
where 
quadriceps 
strength 
disproportionately exceeds that of the hamstrings, has been strongly associated 
with a higher risk of hamstring strains and non-contact anterior cruciate 
ligament (ACL) injuries due to reduced dynamic knee joint stability during 
high-speed movements (Grygorowicz et al., 2017).  
Statement of problem: 
This study will try to answer the following question:  
Will adding mini-squat exercises at different angles (30°,45°, and 60°) to 
leg press exercise influence quadriceps and hamstring strength and H:Q angle in 
football players? 
 
 

4 
 
Purposes of the study:  
The purposes of this study are to 
1. To investigate the difference between adding knee flexion mini-squat 
exercise at different angles (30°, 45°, and 60°) to leg press exercise on 
quadriceps strength in football players. 
2. To investigate the difference between adding knee flexion mini-squat 
exercise at different angles (30°, 45°, and 60°) to leg press exercise on 
hamstrings strength in football players. 
3. To investigate the difference between adding knee flexion mini-squat 
exercise at different angles (30°, 45°, and 60°) to leg press exercise on the 
hamstring-to-quadriceps (H:Q) ratio in football players. 
Significance of the study: 
Football is a high-intensity sport that places repeated stress on the lower 
limbs, especially the knee joint. Lower limb strength, joint stability, and muscle 
balance are critical for optimal performance and injury prevention in football 
players (Brito et al., 2010). Among the most common injuries in football are 
those affecting ACL and hamstring strains, which are often linked to imbalances 
between the quadriceps and hamstrings, typically assessed using the H:Q ratio 
(Croisier et al., 2008). A low H:Q ratio is associated with poor neuromuscular 
control and increased injury risk, particularly during sprinting, deceleration, and 
cutting movements (Baroni et al., 2020). 
Mini squats and leg press exercises are widely used in sports 
rehabilitation and conditioning programs to strengthen the lower extremities. 
Performing mini squats at specific knee flexion angles may help target muscle 
activation more precisely and improve motor control and joint loading strategies 
(Escamilla et al., 2012). While leg press exercises focus on maximal strength 
and power, adding mini squats at varying angles may improve joint mechanics, 

5 
 
increase proprioception, and support functional training in football athletes. 
Despite their individual benefits, limited research has examined the combined 
effect of angle-specific mini squats and leg press exercises on lower limb 
performance and muscle balance in football players (Zhao et al., 2023) . 
Recent studies have highlighted the importance of exercise selection and 
angle specificity in resistance training, showing that different knee angles result 
in varied activation patterns in the quadriceps and hamstrings. However, current 
literature offers limited insight into the effects of integrating mini squat 
exercises with leg press training on injury prevention and functional outcomes 
in athletic populations. In particular, there is a lack of literature on how such a 
combined leg press and mini squat exercise at different angles influences the 
H:Q ratio, lower limb neuromuscular control, and performance in young male 
football players. Therefore, the present study aims to examine whether 
incorporating mini squats performed at varying knee flexion angles into a leg 
press training program can improve muscle balance and lower limb strength in 
football players. The findings may provide valuable guidance for 
physiotherapists, coaches, and sports scientists in developing evidence-based, 
angle-specific exercise protocols tailored to the functional demands of athletes. 
(Watanabe et al., 2020). 
Delimitation: 
This study will be delimited to the following: 
1.  Male football players aged between 18–30 years (Scoz et al., 2021). 
2. Body Mass Index (BMI) between 18.5 and 24.9 kg/m² (Walsh et al., 
2018 & Sattar& Lean, 2009). 
3. Participants will receive 18 training sessions, conducted three days per 
week, over six successive weeks 

6 
 
Basic assumptions:  
1. Participants understood and followed the given instructions during 
assessment and treatment procedures. 
2. Participants did not receive any additional medical or physical therapy 
treatment during the study period. 
Hypotheses will be: 
 
1. There is no statistically significant difference between adding 30°, 45°, and 
60° knee flexion mini-squat exercises to leg press exercise and leg press 
exercise alone on quadriceps strength in football players. 
2. There is no statistically significant difference between adding 30°, 45°, and 
60° knee flexion mini-squat exercises to leg press exercise and leg press 
exercise alone on hamstrings strength in football players. 
3. There is no statistically significant difference between adding 30°, 45°, and 
60° knee flexion mini-squat exercises to leg press exercise and leg press 
exercise alone on the hamstrings-to-quadriceps H:Q ratio in football players. 
 
 
 
 
 
 
 
 
 
 

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Definitions of terms 
Hamstring-to-quadriceps ratio H:Q ratio: 
The H-Q ratio refers to the relative strength of the hamstring muscles 
compared to the quadriceps, typically measured under isokinetic conditions (at 
the same angular velocity). It is calculated as the maximal concentric knee 
flexion strength divided by maximal concentric knee extension strength. A 
conventional ratio of around 0.6 (hamstrings at least 60 % as strong as 
quadriceps) is commonly regarded as a threshold for reducing injury risk, 
particularly to the ACL (Grygorowicz et al., 2017). 
Leg press exercise: 
The leg press is a closed kinetic-chain, compound weight-training 
exercise in which the individual pushes a weighted platform or sled away 
from the body using the legs, typically seated or reclined. It targets the 
quadriceps primarily, with secondary involvement of the hamstrings, gluteus 
maximus, and calves, and is frequently used in athletic training and 
rehabilitation due to its controlled motion and safety features (Da Silva et 
al., 2008). 
Mini squat exercise: 
A mini-squat is a partial squat movement performed in a standing 
position, where the knees and hips are flexed to approximately 45°–60°, 
significantly less than in a full-depth squat. The movement is executed by 
bending the knees as if sitting into a chair and then extending back up, often 
performed with hands supported for balance. Mini-squats are used to 
strengthen the quadriceps and gluteal muscles and to enhance functional 
movement such as sit-to-stand or stair-climbing, while minimizing stress on 
the joints (Escamilla, 2001). Some authors, however, consider mini-squats to 
begin from 15-20° of knee flexion, typically ranging between 30° and 60° 
(Daşkapan et al., 2013). 

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CHAPTER II 
LITREATURE REVIEW 
 
The review of related literature will cover the following topics: (1) 
Anatomy of the quadriceps muscle, (2) Anatomy of the hamstrings muscle, (3) 
Strength training in athletes, (4) Biomechanics of squat exercises, (5) Effect of 
mini squats on quadriceps strength, (6) Effect of mini squats on hamstring 
strength, (7) Effect of mini squats on H:Q ratio, (8) Leg press exercise: purpose 
and muscle activation, (9) Effect of leg press exercise on quadriceps strength, 
(10) Effect of leg press exercise on hamstring strength,(11) Effect of leg press 
exercise on the H:Q ratio, and(12)Assessment of muscle strength and H:Q ratio   
1-Anatomy of quadriceps muscle: 
The quadriceps femoris is the primary extensor of the knee joint and one 
of the most powerful muscle groups in the human body. It is composed of four 
muscles: rectus femoris, vastus lateralis, vastus medialis, and vastus 
intermedius, all of which converge into the quadriceps tendon that inserts into 
the patella and continues as the patellar ligament to the tibial tuberosity 
(Standring, 2016). Among these muscles, the rectus femoris is unique as it 
spans both the hip and knee joints, enabling it to contribute to hip flexion in 
addition to knee extension, while the vasti muscles function primarily in knee 
extension (Moore et al, 2018) (figure 1). 
The origins of these muscles vary, with the rectus femoris arising from 
the anterior inferior iliac spine, the vastus lateralis from the greater trochanter 
and linea aspera, the vastus medialis from the medial linea aspera and 
intertrochanteric line, and the vastus intermedius from the anterior and lateral 
surfaces of the femoral shaft (Standring, 2016). Together, these muscles form a 
layered tendon complex that allows for the efficient transfer of force during 

9 
 
knee extension. Recent anatomical studies have described the presence of an 
additional slip, the tensor vastus intermedius, which contributes to the structural 
complexity of the quadriceps tendon (Grob et al, 2016). 
Functionally, the quadriceps plays a vital role in locomotion and daily 
activities such as rising from a chair, climbing stairs, running, and jumping 
(Herzog, 2017). Within the group, the vastus medialis obliquus (VMO) is 
particularly important for stabilizing the patella during movement and 
preventing lateral displacement, thereby reducing the risk of patellofemoral pain 
syndrome (Powers, 2010). Innervation of the quadriceps arises from the 
femoral nerve (L2–L4), while its vascular supply is derived from branches of 
the femoral artery and the lateral circumflex femoral artery (Moore et al., 
2018). 
  
Fig 1: Anatomy of quadriceps muscle (adopted from Senghas, 1990). 

10 
 
2-Anatomy of hamstrings muscle:  
The hamstring muscles are located in the posterior compartment of the 
thigh and consist of the biceps femoris (long and short heads), semitendinosus, 
and semimembranosus. These muscles share a common origin at the ischial 
tuberosity, except for the short head of the biceps femoris, which originates 
from the femoral shaft. They extend distally to insert on the tibia and fibula: the 
semitendinosus inserts on the medial tibia, the semimembranosus inserts on the 
medial tibial condyle, and the biceps femoris attaches to the head of the fibula 
(Standring, 2016; Moore et al., 2018) (figure 2). 
Functionally, the hamstrings act as powerful hip extensors and knee 
flexors. During gait, they play an essential role in decelerating knee extension at 
the end of the swing phase and contribute to hip extension during stance, 
making them critical for sprinting and explosive activities (Schache et al., 
2012). Their biarticular nature, spanning both the hip and knee joints, increases 
their susceptibility to injury, particularly under eccentric loading conditions 
such as high-speed running (Askling et al., 2007). 
The hamstrings are innervated by the sciatic nerve, with the tibial division 
supplying all except the short head of the biceps femoris, which is innervated by 
the common fibular division (Moore et al., 2018). Their blood supply is derived 
mainly from perforating branches of the profunda femoris artery, with additional 
contributions from the inferior gluteal artery (Standring, 2016). 

11 
 
Fig 2: Anatomy of hamstrings muscle (adopted from Senghas, 1990). 
 
3-Strength Training in Athletes: 
Strength training is a fundamental component of athletic conditioning, 
particularly for sports that require explosive power, speed, and agility, such as 
football. Football involves rapid acceleration, deceleration, jumping, cutting, 
and high-impact collisions, all of which demand optimal muscular strength and 
neuromuscular coordination (Comfort et al., 2014). Strength training improves 
the functional capacity of athletes by enhancing force production, 
neuromuscular efficiency, and joint stability key factors for high-level 
performance in football (Suchomel et al., 2016). 

12 
 
Research indicates that well-structured resistance training programs can 
significantly increase sprinting speed, vertical jump height, and change of 
direction ability in football players (Turner et al., 2014). These improvements 
are attributed to enhanced muscle cross-sectional area, increased motor unit 
recruitment, and improved rate of force development (RFD). Moreover, strength 
training enhances the robustness of movement patterns, allowing athletes to 
generate force more efficiently and reduce energy expenditure during match-
play activities (Cormie et al., 2011). 
The lower extremities, particularly the hamstrings, quadriceps, and 
gluteal muscles, are prone to both strength imbalances and overuse injuries in 
football players. One of the most commonly observed deficits is the (H:Q) 
strength ratio imbalance. An insufficient H:Q ratio may predispose athletes to 
hamstring strains and ACL injuries due to reduced dynamic knee stability 
(Croisier, 2004). Additionally, repeated eccentric loading of the lower limb 
muscles, especially during sprinting and deceleration, increases the risk of 
muscle damage if not properly conditioned through strength training (Schache 
et al., 2012). 
Knee valgus, patellofemoral pain, and Achilles tendinopathy are also 
frequently reported among athletes with poor muscular strength or control in the 
lower extremities (Myer et al., 2008). Strength training, particularly exercises 
targeting the posterior chain and hip abductors, has been shown to correct 
biomechanical deficiencies and lower the incidence of non-contact injuries 
(Zebis et al., 2009). 
Resistance training provides a broad spectrum of physiological and 
performance-related benefits for athletes. From a muscular perspective, it 
promotes hypertrophy, enhances tendon stiffness, and strengthens connective 
tissues all crucial for absorbing high forces during dynamic sports movements It 

13 
 
also improves joint proprioception and stability, contributing to better 
coordination and control under competitive conditions. (Wirth, Hartmann, 
Mickel, Szilvas, & Keiner, 2016). 
Functionally, resistance training improves maximal strength, explosive 
power, muscular endurance, and resilience to fatigue, making it indispensable 
for both elite and amateur football players (Kraemer & Ratamess, 2004). It 
further enables athletes to tolerate higher training volumes and intensities, 
thereby accelerating performance adaptations and supporting long-term athletic 
development (Suchomel et al., 2016). 
Importantly, targeted resistance exercises such as squats, lunges, and leg 
press specifically develop the prime movers of the hip, knee, and ankle joints. 
These movements simulate key phases of sprinting, kicking, and tackling in 
football, making them not only preventive but also highly specific to the 
demands of the sport (Del Monte et al, 2020). 
4- Biomechanics of Squat Exercises: 
Squats are typically classified based on the depth of descent, which is 
defined by the angle at the knee joint and the position of the hip relative to the 
knee. A mini squat (also called a quarter squat) involves knee flexion of 
approximately 40°–50°, while a parallel squat reaches around 90° of knee 
flexion, and a deep squat exceeds 110°–130°, often going until the thighs are 
below parallel to the floor Each variation targets specific muscle groups to 
different extents and places varying levels of mechanical stress on joints and 
tissues. (Caterisano et al., 2002). 
Mini squats are often used in early rehabilitation phases and for athletes 
with limited mobility or knee issues, as they minimize compressive forces on 
the patellofemoral joint and reduce anterior shear at the knee. In contrast, deep 
squats recruit a larger range of motion and activate a greater portion of 

14 
 
musculature, but they also increase joint loading, particularly at the hips and 
knees (Hartmann et al., 2013). 
Squat exercises primarily engage the quadriceps femoris, hamstrings, 
gluteus maximus, and adductor magnus, along with stabilizing contributions 
from the erector spinae, core musculature, and calves. The level of activation for 
each muscle group is strongly influenced by squat depth, foot positioning, trunk 
angle, and external load placement (Escamilla, 2001). 
In general, quadriceps activation is highest during the concentric 
(ascending) phase of the squat and increases as knee flexion deepens. The 
gluteus maximus becomes more active at greater hip flexion angles, especially 
during deep squats, contributing significantly to hip extension in the upward 
phase (Schoenfeld, 2010). Although the hamstrings are not primary movers in 
squats, they act synergistically with the glutes to stabilize the hip and counter 
anterior tibial translation, especially in posterior chain–focused squat variants 
like box squats (Yavuz et al., 2015). 
The adductor magnus also plays a key role during squatting, particularly 
in deep squats, by assisting in hip extension and providing frontal plane 
stability. The erector spinae and core muscles (e.g., rectus abdominis and 
obliques) contribute to spinal stiffness and postural control, especially when 
heavier loads are applied (McKean et al., 2010). 
The depth of the squat significantly alters the distribution of forces and 
muscle recruitment patterns. As squat depth increases, so does the range of 
motion at the hip and knee joints, which in turn results in greater activation of 
the posterior chain. Research using surface electromyography (EMG) has 
consistently shown that deeper squats result in higher activation of the gluteus 
maximus and adductor magnus compared to shallow squats (Bryanton et al., 
2012). 

15 
 
Deeper squats also lead to higher compressive and shear forces at the 
knee, particularly on the patellofemoral and tibiofemoral joints. However, these 
forces remain within tolerable physiological limits for healthy individuals and 
are offset by the increased activation of stabilizing muscles at shallower angles 
(mini squats), quadriceps activation dominates, while gluteal and hamstring 
contributions are relatively lower. This makes mini squats more quadriceps-
focused and less functional for activities requiring powerful hip extension. 
(Schoenfeld, 2010). 
Furthermore, joint angle affects length-tension relationships, which 
influence force output. At deeper angles, muscles operate closer to their optimal 
length for force production, particularly the glutes and adductors. The use of 
different squat depths can therefore be strategically programmed to emphasize 
specific performance outcomes or to manage loading during rehabilitation 
phases (Hartmann et al., 2013). 
Importantly, joint angle and depth also have a direct influence on the 
torque demands placed on the knee and hip joints. As knee flexion increases, the 
external moment arm acting on the knee becomes longer, thereby increasing 
torque requirements for the quadriceps. Simultaneously, the hip extensors must 
generate more force to overcome the increased hip flexion, especially in athletes 
performing squats with a forward lean or deeper descent (Swinton et al., 2012). 
5-Effect of Mini Squats on Quadriceps Strength: 
Mini squats, typically performed between 0°–60° of knee flexion, are 
widely recognized for their effectiveness in strengthening the quadriceps while 
minimizing stress on the knee joint structures. This partial range of motion 
specifically engages the rectus femoris, vastus lateralis, vastus medialis, and 
vastus intermedius, with greater activation of the vastus medialis oblique 
(VMO), which plays a crucial role in patellar stabilization and knee extension 
mechanics (Escamilla et al., 2012).  

16 
 
The reduced depth of the squat makes it a safer option for athletes 
recovering from injury, as it reduces compressive and shear forces across the 
tibiofemoral and patellofemoral joints compared to deep squats (Caterisano et 
al., 2002). Furthermore, progressive training with mini squats has been shown 
to significantly enhance quadriceps torque and functional performance in both 
healthy and injured populations, making it a valuable addition to rehabilitation 
and athletic conditioning programs (Earl & Hoch, 2011; Isear et al., 1997). 
6-Effect of Mini Squats on Hamstring Strength: 
While squats are primarily quadriceps-dominant, mini squats also recruit 
the hamstring muscles, albeit to a lesser extent compared to exercises involving 
deeper knee flexion or hip extension (Caterisano et al., 2002). The hamstrings 
function as stabilizers during the squatting motion by controlling anterior tibial 
translation and assisting in hip extension (Escamilla et al., 2001).  
Electromyographic studies indicate that hamstring activation increases 
with the load and the degree of knee flexion; however, even in partial squats, the 
hamstrings remain active to provide dynamic stabilization, particularly when 
maintaining proper trunk posture (Schoenfeld, 2010). Strengthening the 
hamstrings through mini squats may not be as pronounced as through exercises 
such as Romanian deadlifts or Nordic hamstring curls, but their role in co-
activation during squatting tasks is vital for balanced knee mechanics and 
reducing injury risk in athletes (Ebben et al., 2009). 
7-Effect of Mini Squats on H:Q Ratio: 
 
The hamstring-to-quadriceps ratio (H: Q) is a critical indicator of knee 
joint stability, particularly in athletic populations where knee injuries, such as 
ACL tears, are common (Croisier et al., 2008). Mini squats, by simultaneously 
engaging 
both 
quadriceps 
and 
hamstrings, 
contribute 
to 
improving 
neuromuscular balance around the knee. Although mini squats are more 
quadriceps-dominant, the co-activation of hamstrings during the exercise 

17 
 
enhances the functional stability of the joint, supporting a healthier H:Q ratio 
(Aagaard et al., 1998).  
 
Studies have suggested that athletes with low H:Q ratios are at greater 
risk of non-contact ACL injuries, and integrating closed-chain exercises like 
mini squats into training can reduce such risks by promoting balanced muscular 
adaptation (Hewett et al., 2005). Additionally, combining mini squats with 
other hamstring-dominant exercises has been shown to optimize the H:Q ratio, 
thereby improving both performance and injury prevention outcomes in sports 
settings (Coombs & Garbutt, 2002; Myer et al., 2008). 
8- Leg Press Exercise: Purpose and Muscle Activation: 
The leg press is a closed kinetic chain resistance exercise primarily 
designed to develop lower limb strength through a controlled movement pattern. 
It typically involves pushing a platform upward or outward with the feet while 
the back remains supported against a padded seat or backrest. Unlike the squat, 
which requires the body to move around the barbell in free space, the leg press 
constrains the path of movement to a fixed trajectory. The two most common 
types are the 45-degree incline leg press and the horizontal leg press, both of 
which allow for a relatively high external load with reduced axial compression 
on the spine (Escamilla et al., 2001). 
During the leg press, force is generated primarily in the sagittal plane, 
involving hip and knee extension and ankle plantarflexion. The movement 
begins with the knees flexed and the feet positioned shoulder-width apart on the 
platform. As the platform is pushed away, the knees and hips extend 
simultaneously, mimicking a squatting-type motion. The joint angles, foot 
placement, and seat inclination all influence the mechanical demand placed on 
different lower limb muscles Unlike the squat, the leg press significantly 
reduces the balance and stabilization requirements, making it a safer and more 

18 
 
accessible option for individuals with limited motor control or during early 
rehabilitation. (Martínet al., 2020). 
The leg press primarily activates the quadriceps femoris group, including 
the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. It 
also recruits the gluteus maximus, hamstrings (particularly the biceps femoris 
and semitendinosus), and gastrocnemius and soleus muscles at the ankle joint 
(Da Silva et al., 2008). 
The leg press exercise elicits varying patterns of muscle activation 
depending on load, depth, and foot positioning, making it a versatile lower limb 
strengthening tool. During the knee extension phase, the quadriceps muscles—
particularly the vastus lateralis and vastus medialis demonstrate the highest 
electromyographic (EMG) activity, especially under heavier loads or when the 
knees are in greater degrees of flexion (Escamilla et al., 2001). As the 
movement approaches full knee extension, quadriceps engagement peaks, 
ensuring efficient force production. The gluteus maximus becomes 
progressively more involved as hip flexion increases, a pattern often 
accentuated when the feet are positioned higher on the platform. This upward 
placement shifts the mechanical load proximally, encouraging greater hip 
extensor involvement Although the hamstrings are not primary movers in the 
leg press compared to hip-dominant exercises, they contribute to hip extension 
and co-contract with the quadriceps, thereby enhancing knee joint stability 
throughout the push phase. (Paoli et al., 2009). 
Additionally, calf muscles such as the gastrocnemius and soleus play a 
supportive role, especially during the terminal phase of the movement. When 
the toes exert pressure against the platform, these muscles facilitate ankle 
plantarflexion, contributing to full lower limb extension. The muscle 
recruitment pattern is highly dependent on foot placement: a higher foot 

19 
 
position increases gluteal and hamstring activation, a lower placement 
emphasizes the quadriceps, while a wider stance preferentially recruits the 
adductor magnus This adjustability allows the leg press to be tailored to specific 
muscular targets or to accommodate athletes with limited joint range of motion, 
making it particularly useful in rehabilitation and performance conditioning 
programs. (Escamilla et al., 2001; Paoli et al., 2009). 
The leg press and the squat both target similar muscle groups and 
movement patterns, yet they differ considerably in terms of biomechanical 
loading, neuromuscular activation, and risk profile. The leg press allows for 
greater external loads due to the fixed machine path and reduced stability 
requirements. However, higher loads on the leg press do not always equate to 
greater functional strength because the body’s stabilizers are underutilized 
compared to free-weight squats (Wirth et al., 2016). 
The leg press exercise typically allows for greater peak force output 
compared to the squat, largely due to the external support provided by the 
machine, which minimizes the requirement for postural stabilization (Hoffman 
et al., 2009). In contrast, squatting involves axial loading of the spine and 
requires substantial activation of the core musculature and spinal erectors to 
maintain balance and proper alignment throughout the movement (McBride et 
al., 1999). Force plate analyses and electromyographic (EMG) studies suggest 
that although the leg press elicits higher quadriceps activation especially under 
heavy loads—the squat offers a more holistic recruitment pattern involving the 
gluteus maximus, hamstrings, and trunk stabilizers This comprehensive 
activation pattern enhances neuromuscular efficiency and full-body strength, 
which are key components in athletic performance. (Escamilla, 2001). 
From a biomechanical perspective, the leg press imposes significantly 
less axial compression on the spine compared to the squat, making it a preferred 

20 
 
choice for individuals with spinal limitations or during rehabilitation phases 
(Callaghan & McGill, 2001). However, improper form during deep leg press 
particularly excessive knee flexion combined with posterior pelvic tilt can 
increase shear forces on both the lumbar spine and the posterior structures of the 
knee joint. These risks underscore the importance of maintaining neutral spine 
alignment and controlled depth when executing the leg press. Conversely, when 
squats are performed with proper technique and load management, they offer a 
more functional distribution of joint forces. Squats facilitate full kinetic chain 
involvement, promoting joint stabilization and alignment through dynamic 
control (Escamilla, 2001). 
In terms of functional carryover to athletic activities, squats are superior 
due to their demand on dynamic stability, proprioception, and postural control. 
These qualities are critical for sport-specific tasks such as sprinting, jumping, 
and rapid changes in direction particularly in football where multidirectional 
agility and explosive power are essential (Thomas et al., 2009). On the other 
hand, the leg press provides value in isolating specific muscle groups and 
enhancing maximal force capacity, particularly at targeted joint angles. It is 
especially effective during early phases of strength training or when addressing 
unilateral or muscular imbalances (Paoli et al., 2009). 
9-The effect of Leg Press Exercise on Quadriceps Strength: 
 
The leg press exercise is one of the most widely utilized resistance 
training movements for targeting the quadriceps due to its ability to isolate and 
load the knee extensors in a controlled, closed-kinetic-chain position. By 
allowing the individual to push against a fixed platform, the exercise 
emphasizes knee extension torque while minimizing balance demands, making 
it effective for both rehabilitation and performance enhancement (Escamilla et 
al., 2001).  

21 
 
 
During the concentric phase, the quadriceps are primarily activated to 
extend the knee, while the eccentric phase requires them to control the descent 
of the load. Repeated performance of the leg press leads to hypertrophy and 
increased maximal voluntary contraction of the quadriceps, which contributes to 
enhanced lower-limb strength and improved functional performance in athletes 
(Schoenfeld, 2010). Furthermore, the closed-chain nature of the exercise has 
been shown to replicate functional movement patterns more closely than open-
chain exercises, thereby offering benefits in terms of sports specificity and joint 
stability (Pincivero et al., 2004). 
10-The effect of Leg Press Exercise on Hamstring Strength: 
 
Although the leg press is often regarded as a quadriceps-dominant 
exercise, the hamstrings play a supportive role during execution. They are 
primarily engaged during hip extension and act synergistically with the gluteal 
muscles to stabilize the pelvis and assist in the upward phase of the movement 
(Wright et al., 1999).  
 
Electromyographic 
(EMG) 
studies 
have 
demonstrated 
moderate 
activation of the hamstrings during leg press performance, especially at deeper 
knee flexion angles, where greater hip extension demand is imposed (Escamilla 
et al., 1998). While the hamstrings are not the primary movers, regular 
performance of the leg press can indirectly improve hamstring strength through 
stabilization and co-contraction with the quadriceps, which is important for 
injury prevention and overall muscular balance (Solomonow et al., 1987). 
However, compared to direct hamstring exercises such as Romanian deadlifts or 
leg curls, the hypertrophic and strength gains in the hamstrings from leg press 
alone remain relatively limited (Ebben et al., 2009). 
11-The effect of Leg Press Exercises on H: Q Ratio: 
 
The leg press is a closed kinetic chain exercise that predominantly targets 
the quadriceps due to the knee extension component of the movement. As a 

22 
 
result, long-term exclusive reliance on the leg press may disproportionately 
increase quadriceps strength compared to the hamstrings, leading to a reduced 
H:Q ratio and elevating the risk of knee injuries, particularly ACL tears and 
patellofemoral pain. A reduced H:Q ratio reflects insufficient hamstring strength 
to counterbalance quadriceps dominance, which compromises knee joint 
stability during high-demand activities such as sprinting, cutting, or jumping 
(Croisier et al., 2008). 
 
However, research indicates that the contribution of hamstrings during 
the leg press varies depending on technique and joint positioning. For example, 
performing the leg press with greater hip flexion angles or deeper ranges of 
motion increases posterior chain recruitment, allowing the hamstrings and 
gluteal muscles to contribute more effectively. Additionally, tempo variations, 
unilateral leg press, and eccentric-focused training have been suggested to 
enhance co-activation of the hamstrings, thereby helping maintain a healthier 
H:Q ratio (Jaric, 2002). 
 
To optimize muscle balance, leg press training should not be performed in 
isolation but rather integrated with targeted hamstring-dominant exercises such 
as Nordic hamstring curls, Romanian deadlifts, or stability ball leg curls. 
Combining these exercises ensures proportional development between the knee 
extensors and flexors, preserving an optimal H:Q ratio and reducing the 
likelihood of muscular imbalances and knee-related pathologies (Alonso-
Cortés et al., 2022; Aagaard et al., 1998). 
12-Assessment of muscle strength, H:Q ratio, and ROM: 
• Assessment of muscles strength: 
Manual Muscle Testing (MMT) represents the most basic method for 
evaluating quadriceps and hamstring strength, relying on the examiner’s 
subjective judgment of resistance to applied force. Although widely 

23 
 
implemented in clinical settings due to its simplicity and cost-effectiveness, 
MMT demonstrates limited validity and reliability, particularly for detecting 
subtle strength deficits or in individuals with high levels of muscular strength 
(Cuthbert & Goodheart, 2007). 
Handheld dynamometry (HHD) provides a more objective alternative by 
quantifying force output of the knee extensors and flexors. Reported reliability 
values for HHD are generally strong, with intraclass correlation coefficients 
(ICCs) ranging from 0.76 to 0.96 for both quadriceps and hamstrings 
(Thorborg et al., 2013). Nonetheless, outcomes are influenced by examiner 
strength, stabilization strategies, and patient positioning, which reduce its 
consistency compared with isokinetic assessment, particularly in athletic 
populations (Mentiplay et al., 2015). 
Isokinetic dynamometry, most commonly performed using systems such 
as the Biodex, is considered the gold standard for assessing quadriceps and 
hamstring performance. It provides dynamic, objective, and reproducible 
measures of torque during concentric and eccentric contractions under 
controlled angular velocities (Drouin et al., 2004). In addition to peak torque, 
this method yields further performance parameters including total work, power, 
and fatigue index that offer a comprehensive understanding of muscular 
capacity (Impellizzeri & Marcora, 2009). 
A distinct advantage of isokinetic dynamometry lies in its ability to assess 
the H:Q ratio. The conventional H:Q ratio is defined as the relationship between 
concentric hamstring and concentric quadriceps peak torque, whereas the 
functional H:Q ratio compares eccentric hamstring to concentric quadriceps 
torque (Aagaard et al., 1998). These indices are valuable for evaluating 
muscular balance across the knee joint, informing injury risk assessment, 

24 
 
rehabilitation progress, and return-to-sport readiness (Coombs & Garbutt, 
2002). 
The validity of isokinetic dynamometry is well established. Torque is 
measured directly via the device’s lever arm at predefined angular velocities, 
demonstrating strong criterion validity in comparison with other strength 
assessment methods. Furthermore, the ability to isolate joint movements and 
regulate contraction speed enhances construct validity, making it particularly 
suitable for both clinical practice and research applications (Feiring et al., 
1990). 
Reliability has been consistently confirmed across studies. Test–retest 
reliability of isokinetic quadriceps and hamstring strength has shown excellent 
results, with ICCs ranging from 0.85 to 0.99 depending on contraction mode 
and angular velocity (Maffiuletti et al., 2007; Impellizzeri & Marcora, 2009). 
H:Q ratio measurements similarly demonstrate strong reproducibility, with ICCs 
typically reported between 0.82 and 0.95 (Ayala et al., 2012). The standard 
error of measurement (SEM) for peak torque generally falls between 5–8%, 
indicating minimal variability due to measurement error (Dirnberger et al., 
2012). Moreover, Biodex dynamometers have demonstrated high inter-device 
reliability, ensuring consistent outcomes across different testing sites (Feiring et 
al., 1990). 
• Assessment of range of motion ROM: 
Range of motion (ROM) assessment of the knee joint is commonly 
performed using different clinical and laboratory-based tools, with the 
goniometer being the most widely applied method in both research and clinical 
practice. The universal goniometer is inexpensive, portable, and easy to use, 
making it a gold standard in routine physiotherapy assessments. Previous 
studies have shown that the universal goniometer demonstrates excellent intra-

25 
 
rater reliability, with intraclass correlation coefficients (ICC) ranging from 0.90 
to 0.99 for knee flexion and extension (Brosseau et al., 2001). Inter-rater 
reliability has also been reported as high, with ICC values between 0.85 and 
0.95, depending on examiner experience (Gogia et al., 1987). Its validity in 
comparison to radiographic measurements has been established, showing strong 
correlations (r = 0.93–0.97) between goniometric and radiographic values for 
knee joint angles (Sadeghi et al., 2015). 
Digital inclinometers and smartphone-based goniometric applications 
have been introduced as alternatives. Digital inclinometers have demonstrated 
excellent intra-rater reliability (ICC = 0.97) and inter-rater reliability (ICC = 
0.94) for knee flexion measurements, with validity coefficients up to r = 0.96 
compared to radiographic standards (Kolber & Hanney, 2012). Smartphone-
based applications have also shown promising results, with studies reporting 
ICC values of 0.85–0.95 for knee ROM compared to the universal goniometer. 
These emerging tools provide greater accessibility, although they remain 
complementary rather than replacements for traditional goniometry in clinical 
trials (Ockendon & Gilbert, 2012). 
Radiographic imaging and 3D motion analysis systems are considered 
reference standards for ROM assessment, particularly in research contexts. 
Radiographic assessment demonstrates nearly perfect validity, as it directly 
visualizes joint angles; however, its practicality is limited by cost and radiation 
exposure. Three-dimensional motion capture systems, though resource-
intensive, have been reported to achieve validity coefficients above 0.95 
compared to radiographic assessment, and inter-rater reliability exceeding 0.90 
for dynamic knee ROM. Despite these advances, goniometry remains the most 
practical and reliable method in routine clinical and sports settings due to its 
balance between validity, reliability, and accessibility (Windolf et al., 2008). 

26 
 
CHAPTER III 
SUBJECTS, MATERIALS AND METHODS 
 
The current study aims to investigate whether incorporating mini squat 
exercises at different knee flexion angles into a leg press training program 
enhances hamstring- quadriceps ratio H:Q ratio in football players. 
Design of the study: 
This study will follow a randomized controlled trial (RCT) design. 
Study setting 
The study will be conducted at the outpatient physical therapy clinic of Jazan 
University Hospital, kingdom of Saudi Arbia. 
Sample size: 
The sample size for this study was determined using G*Power version 
3.1.9 (Heinrich-Heine-University, Düsseldorf, Germany). An a priori power 
analysis was conducted for a repeated measures MANOVA with between-
subject factors, setting the alpha level (α) at 0.05, desired power (1 - β) at 0.80, 
Pillai’s trace (V) at 0.1989, and effect size f²(V) at 0.2877, targeting isometric 
muscle strength across four independent groups. The analysis indicated a 
minimum required sample size of 48 participants, allocating 12 per group. To 
compensate for possible dropouts, the total sample was increased to 60 
participants, with 15 individuals per group (Wirth et al., 2016) (figure 3). 
 
 
 
 
 

27 
 
 
 
 
 
 
 
 
 
 
Fig 3:sample size calculation using G power 
 
Randomization, allocation concealment, and blinding  
The enrolled participants will be randomized in a simple randomization 
way using (www.randomizer.org/links/) by another participant not involved in 
the data collection. Allocation concealment will be ascertained using sealed, 
opaque, sequentially numbered envelopes. The participants will be blinded to 
the assigned intervention group. 
Participants  
Sixty male football players from Al-Ahli and Al-Ittihad football clubs in 
the Kingdom of Saudi Arabia. Participants will be asked to sign a written 
informed consent that includes participation in the experimental trial, 
permission to use data and/or pictures, and informing them of their right to 
withdraw at any time (Appendix I). 
Participants will be randomized into 4 equal groups: an experimental 
group (A, B, and C), and a Control group (D).  
 
 
 

28 
 
Experimental groups (A, B, and C) 
Group A: Fifteen participants will receive mini-squat exercises at 30° knee 
flexion and leg press exercises  
Group B: Fifteen participants will receive mini-squat exercises at 45° knee 
flexion and leg press exercises 
Group C: Fifteen participants will receive mini-squat exercises at 60°and leg 
press exercises 
Control group D: Fifteen participants will receive leg press exercise program 
only. 
Inclusion criteria: 
Participants having the following criteria will be included in the study: 
1. Male football players aged between 18–30 years (Scoz et al., 2021). 
2. Body Mass Index (BMI) between 18.5 and 24.9 kg/m² (Walsh et al., 2018 & 
Sattar& Lean, 2009). 
3. Currently training or playing with a registered football club/team. 
4. Hamstring-to-Quadriceps (HQ) strength ratio of ≥ 0.6 (Çelebi et al., 2018). 
5. Having no oral or injectable non-steroidal anti-inflammatory drugs 
(NSAID), 2weeks before starting study. 
6. Having no oral injectable corticosteroids 3 months before starting the study. 
Exclusion criteria: 
Participants having any of the following criteria will be excluded from the 
study: 
1. History of acute or chronic injury to the knee, hip, or ankle joint 
2. Undergoing any other rehabilitation or physical therapy programs during the 
six weeks before starting the study  
3. Diagnosed with neurological or systemic disorders affecting muscle function 
or balance 

29 
 
4. Participation in competitive sports or high-intensity training outside the 
study protocol during the study period 
5. Presence of any contraindication to exercise, such as uncontrolled 
hypertension or heart conditions. 
6. Clinically free from lower limb injuries. 
7. Having no history of neurological, cardiovascular, or musculoskeletal 
disorders. 
Instrumentation: 
a. Isokinetic dynamometry: 
Isokinetic dynamometry (Biodex System 4 Pro) is considered the gold 
standard for assessing muscle strength and HQ ratios, offering valid and reliable 
measurements through controlled torque assessment during concentric and 
eccentric contractions. Its criterion validity is well established, and reliability is 
consistently high, with ICCs ranging from 0.85 to 0.99. Furthermore, its ability 
to calculate both conventional and functional H:Q ratios provide a reproducible 
measure of knee muscle balance, making it highly valuable for evaluating injury 
risk, rehabilitation outcomes, and return-to-sport readiness (Ayala et al., 2012) 
(figure 4).  
 
Fig 4: Isokinetic dynamometry device (Biodex System 4 Pro, Biodex Medical Systems, 
Inc., Shirley, NY, USA) (adopted from Sinacore et al. 2017). 

30 
 
b. leg press machine (FL1801 Isolateral Leg Press): 
Fig 5: Leg press machine (FL1801 Isolateral Leg Press, BodyKore Inc., Garden Grove, 
CA, USA) (adopted from BodyKore Inc., 2025). 
c. Goniometer (Jamar Plus+ Digital 8): 
Digital goniometers provide more precise joint range of motion (ROM) 
measurements than traditional goniometers by offering direct electronic 
readouts, reducing examiner error. They have demonstrated excellent reliability 
and validity, with intra-rater ICC values up to 0.96 for knee flexion and 0.92 for 
extension, and inter-rater ICCs ranging from 0.88 to 0.94. These results 
highlight their accuracy and reproducibility, making them particularly useful in 
research and advanced clinical practice (Kolber & Hanney, 2012) (figure 6). 

31 
 
 
Fig 6: Goniometer (Jamar Plus+ Digital 8” Goniometer, China) (adopted from Jeon et 
al., 2024). 
Assessment procedures: 
Participants will be interviewed, and they will be checked for eligibility 
according to pre-mentioned inclusion criteria. Participants who will be eligible 
for the study will sign a written consent form, and demographic data regarding 
height, weight, and BMI will be calculated and recorded. The pretest will be 
performed 3 days after a familiarization test, which included the same tests in 
the same order. The same tests will be carried out again 3 days after the last 
training session. 
The assessment procedure will include the following: 
1-Measurenent of quadriceps strength: 
- The participant will be seated on the isokinetic dynamometer chair, with 
proper posture and alignment ensured. 
- The chest, pelvis, thigh, and ankle will be stabilized using adjustable straps 
to minimize compensatory movements. 
- The lateral femoral epicondyle (the anatomical axis of the knee joint) will be 
aligned with the mechanical axis of the dynamometer arm. 
- The lever arm of the dynamometer will be securely attached to the 
participant’s lower leg, just above the ankle, using a padded cuff. 

32 
 
- Test Parameter Settings will be: 
• Mode: Concentric contraction. 
• Velocity: Commonly set at 60°/s for maximal strength.  
• The range of motion (ROM): between 90°knee flexion to full knee 
extension. 
• Repetitions: 3–5 maximal repetitions. 
- The participant will be allowed to perform a submaximal warm-up trial to 
become familiar with the movement and resistance. 
- The participant will be instructed to perform maximal knee extension against 
the resistance of the device, moving from a flexed to an extended position. 
- The test will be conducted unilaterally, assessing one leg at a time. 
- The participant will be encouraged to exert maximal effort during each 
repetition. 
- The isokinetic device will record key outcome measures including peak 
torque (Nm), average power, and total work for each repetition. These values 
will be used to quantify quadriceps strength (figure 7). 
2- Measurement of hamstrings muscle strength: 
 
All previously described quadriceps muscle evaluation procedures will be 
applied for the hamstrings muscle strength test; however, the range of motion 
will be set from full knee extension, and the participant will be instructed to 
actively bend the knee against the resistance of the device to 90°. 
3-Hamstring to quadriceps H:Q ratio calculation: 
H:Q ratio will be calculated by use this formula: 
𝑯: 𝑸 𝑹𝒂𝒕𝒊𝒐= (𝑯𝒂𝒎𝒔𝒕𝒓𝒊𝒏𝒈 𝑷𝒆𝒂𝒌 𝑻𝒐𝒓𝒒𝒖𝒆 (𝑵𝒎)
𝑸𝒖𝒂𝒅𝒓𝒊𝒄𝒆𝒑𝒔 𝑷𝒆𝒂𝒌 𝑻𝒐𝒓𝒒𝒖𝒆 (𝑵𝒎)) 
     - Value interpretation: 
• < 0.5: hamstring weakness. 
• 0.5-0.7: normal range. 
• 0.8-1: strong hamstring. 

33 
 
 
Fig 7: quadriceps and hamstring muscles strength measurement by isokinetic 
dynamometer device (adopted from Sinacore et al. 2017). 
 
Treatment procedures: 
1) Control group D: The participant will receive 18 sessions of leg press 
exercise using a leg press machine, conducted over a six-week period. Each 
training session will consist of 7 sets of 10 repetitions, with inter-set rest 
intervals of 90 seconds (Wirth et al., 2016 a) Before starting the leg press 
program, a standardized warm-up consisted of 5 min of submaximal cycling on 
an ergometer and 2 to 3 sets of moderate loaded squats with 6 repetitions each. 
 
 

34 
 
 10 Repetition Max (10RM) Test:  
The 10-repetition maximum (10RM) test will be conducted to determine the 
initial training load as a following:  
• The machine will be loaded with a light weight (approximately 25–30% 
of the participant’s body weight). 
• The participant will perform 10 repetitions using proper form. 
• The weight will be increased gradually (by 5–10 kg) after each successful 
attempt. 
• This process will continue until the participant reaches a weight they can 
complete for 10 repetitions with good form, but with difficulty during the 
final 2 reps. 
• That weight will be recorded as the participant’s 10 Repetition Maximum 
(10RM). 
• Strength training will then begin at 75–85% of the determined 10RM 
(Piper et al., 2021). 
Leg Press Exercise: 
1. The seat and backrest of the leg press machine will be adjusted to 
position the participant’s hips and knees at approximately 90 degrees of 
flexion to ensure a comfortable and standardized starting posture. 
2. The participant’s feet will be positioned shoulder-width apart on the 
footplate, with the toes slightly externally rotated and the heels in full 
contact with the platform. 
3. The participant will maintain full contact with the backrest throughout the 
exercise, with the head and spine supported. The side handles will be 
grasped to enhance postural stability and balance. 

35 
 
4. The exercise will commence from a flexed knee position, with particular 
attention given to maintaining proper knee alignment over the feet, 
avoiding any medial or lateral deviation. 
5. The participant will extend the knees and hips to press the platform 
upward, taking care to avoid full knee lockout at the end of the 
movement. 
6. The platform will then be returned to the initial position in a controlled 
manner through knee flexion, maintaining proper form throughout the 
eccentric phase (figure 8). 
 
Fig 8: Leg press exercise adopted from (adapted from Martín et al., 2020). 
 
2) Experimental groups: The participant in each subgroup (A, B, and C) will 
perform the same leg press exercise protocol applied for group D followed by 
mini squat exercise program with 5 min of submaximal cycling on an ergometer 
between 2 treatment programs. A total of 18 sessions will be conducted over a 
six-week period as follows: 

36 
 
1. Group A: participants will receive mini-squat program at 30° in addition to 
leg press program 
2. Group B: participants will receive mini squat program at 45° in addition to 
leg press program 
 
3. Group C: participants will receive mini-squat at 60° in addition in addition 
to leg press program 
Mini-squat program: 
1. Participants will stand barefoot or wear flat training shoes on a stable 
surface, placing their feet shoulder-width apart with toes slightly pointed 
outward. 
2. A goniometer will be used during the first session to measure the target knee 
flexion angle (30° for group A, 45° for group B, and 60° for group C) 
demonstrated once by the examiner on one leg while the participant stands 
still. This will be followed by passive guidance into the used angles to help 
the participant recognize the posture and depth, with instructions to 
remember the sensation for future sessions; goniometer use will be repeated 
in later sessions only if corrective feedback is required. 
3.  Mini-squat session will last 10 minutes. Squat will be performed in a slow 
and controlled manner (approximately 2 seconds down and 2 seconds up), 
with short rests of 15–30 seconds allowed every 1–2 minutes as needed. 
Approximately six minutes of active squatting will be completed per session, 
with the remaining time allocated for brief rests and transitions (adapted 
from Hartmann et al., 2016) (figure 9). 

37 
 
. 
Fig 9: Mini squat exercise (adopted from Prentice, 2024). 
Statistical analysis 
All analyses were carried out using IBM SPSS Statistics version 27 (IBM Corp., 
Chicago, IL, USA). 
• Subject characteristics will be analyzed using ANOVA, while the Chi-
squared test will be used to compare the distribution of the affected side 
among the groups 
• The Shapiro-Wilk test assessed the normality of the data, followed by 
Levene’s test to verify the homogeneity of variances across groups.  
• A mixed MANOVA will be conducted to evaluate the effects of group on 
the dependent variable(s).  
• Post-hoc multiple comparisons were performed with Bonferroni 
correction to adjust for Type I error.  
• Statistical significance was determined at a threshold of p < 0.05.  

38 
 
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Appendix I 
Informed consent form 
I am Mr / Misses / ……………………………………  freely and voluntarily 
consent to participate in research study titled:” Effect of adding mini-squat 
exercises at different angles to leg press exercise on quadriceps and 
hamstring strength and H:Q ratio in athletes” under the direction of 
researcher / . A thorough description of the procedure has been explained, and I 
understand that I may withdraw my consent and discontinue participation in this 
research at any time without prejudice to me.                    
Participant Name: 
Signature:      
Date: