The Effects of Chiropractic Care Combine with a Three-Month Physical Training Program on the Development of Adolescent Basketball Players

This study assessed the effect of routine chiropractic care combined with a three-month strength and conditioning program on the physical performance of adolescent basketball players. Thirty-one male athletes, aged 16-19, from elite Chinese national basketball camps, were divided into experimental and control groups. All subjects received cervical adjustment one time per week done by a team chiropractor. The program aimed to enhance agility, muscular strength, endurance, and speed through professional training. Measurements were taken at baseline, at six weeks, and after twelve weeks, using tests such as the ¾ court sprint, box agility, 1RM back squat, 1RM bench press, 65kg bench press for maximum reps, and 17-line shuttle run. The experimental group showed significant improvements in all metrics except the box agility test, while the control group exhibited fewer substantial changes. Results indicate that structured strength and conditioning programs combined with chiropractic adjustment significantly enhance adolescent athletes’ physical performance. The level of significance was set at p < 0.05. The study concludes that consistent chiropractic care and professionally supervised training are beneficial for adolescent athletes’ development, suggesting the integration of such programs into training routines for adolescent athletes to improve their physical capabilities and minimize injury risks.

Introduction

With the development of kinesiology and exercise science, the concept of strength conditioning and its associated benefits have prevailed among coaches, parents, and adolescents themselves. Concurrently, chiropractic care has gained popularity, especially among young athletes. It has been acknowledged that a well-developed strength conditioning program can benefit children and adolescents by improving general strength, bone density, body composition and self-esteem (Brownet al., 2017; Dahab & McCambridge, 2009; Sánchez Pastoret al., 2023; Schranzet al., 2014). Historically, chiropractic care was often considered no more effective than a placebo. However, recent research suggests that regular chiropractic adjustments can assist with improving joint mobility, enhance athletic performance, and reduce the risk of injuries by ensuring proper alignment of the spine and musculoskeletal system (Eindhovenet al., 2022). Despite these findings, limited research has explored the combined benefits of chiropractic care and strength conditioning programs.

Adolescence is characterized by rapid physical development and the formation of unique motor skills, making it an ideal period for developing speed, strength, agility, endurance, balance and coordination. Early initiation of long-term, periodized strength conditioning is recommended for maximizing strength values in young athletes (Christouet al., 2006; Faigenbaumet al., 2009; Keineret al., 2013). Despite the benefits, concerns about injury risk and the belief that strength training is less effective before puberty due to lower testosterone levels persist among coaches, parents, and clinicians (Dahab & McCambridge, 2009; Keineret al., 2013). Some studies have shown significant strength improvements in adolescent athletes primarily through neural adaptation rather than muscle hypertrophy (Dahab & McCambridge, 2009; Faigenbaum & Micheli, 2017; Falk & Mor, 1996; Legerlotzet al., 2016; Sánchez Pastoret al., 2023).

With the prevalence of chiropractic care, it is important to investigate its combination with strength conditioning programs. This study aims to evaluate the combined effect of chiropractic care and a specific training program on the overall strength conditioning gains in adolescent basketball players.

Methods

Experimental Approach to the Problem

The major objective of this study was to utilize a well-developed three-month strength and conditioning program to train adolescent basketball athletes combined with routine chiropractic cervical manipulation and test their performance in agility, muscular strength, muscular endurance, and speed. All training sessions were conducted by professional strength conditioning coaches. An initial baseline test and two physical tests were conducted at 6 weeks and at the end of the third month during the training period to collect strength and conditioning data. All the tests were administered and recorded by the same person. All subjects were tested in the following areas: body mass (kg), height (cm), ¾ court sprint (s), box agility test (s), 1 RM back squat (kg), 1 RM bench press (kg), 65 kg bench press (max rep), and 17-line shuttle (s).

Subjects

31 male adolescent basketball players (aged 17–19) were selected from elite basketball training camp in China. All subjects were randomly selected from the camp, with players from the varisty team placed into the testing group and players from the novice team placed into the control group. All subjects were informed of the potential risk of injuries and provided written informed consent to participate. For subjects under 18 years of age, informed consent was obtained from their parents. The research design was approved by the Institutional Review Board of Beijing Sports University.

Procedures

Chiropractic Care Protocol

Manual procedures were performed by an experienced team doctor who practised diversified manipulation techniques. All subjects receive chiropractic cervical adjustment (C1–C7) by utilizing a diversified adjustment technique. Subjects received 12 chiropractic manipulations over 12 weeks, targeting the C1–C7 segments.

Training Protocol

The strength training and conditioning program was designed to affect the metrics of the testing prescribed in this study. The detailed training program with exercise selection is showed in Table IV. The program was administered and monitored for a period of 3 months (12 weeks). Prior to beginning the program, testing was performed to establish fitness levels. This was assessed again in the sixth week to evaluate progress. Testing was again performed at the end of the program (12 weeks) to evaluate overall progress. The frequency of training was three days per week throughout the 12-week period. There was a minimum one-day recovery period between each prescribed training session. The training period was separated into two training blocks focusing on 1) Basic Strength/Endurance/Hypertrophy and 2) Maximal Strength/Speed/Power. Each training block lasted for six weeks. The exercise selection was based on the intent of changing the testing metrics. Each exercise is a basic lifting, running, or agility movement common in strength and conditioning practice; it was intentional that there was very minimal exercise variation to create a consistent training approach for this study. The progression and control of intensity (load/speed) followed a linear plan. There are many training styles and philosophies; therefore, for the purpose of this study, a basic approach was adopted in exercise selection, periodization of intensities, and volume of exercise progression. Each athlete was provided with direct supervision of the exercise technique by qualified professionals. The athletes were instructed not to perform extra training outside the prescribed plan to ensure the validity of the study. No injuries were reported during the training. Only minor adjustments were made to the prescribed intensities (load) based on the professional coach’s opinion on a specific athlete’s physical response to training (load). They were not forced to perform at a level beyond their capabilities or techniques.

Testing Protocol

The warm-up was standardized for all participants. The athletes were instructed to perform a general dynamic warm-up 15 min before the test. All tests were completed within one day. The morning test section consisted of a ¾ sprint test, a box agility test, and a 1 RM bench press. The afternoon test section consisted of a 1 RM back squat, a 65 kg bench press test, and a 17-line shuttle run. Anthropometric measurements (height and weight) were performed early in the morning of the testing day. To ensure data validity, the athletes were instructed to have no beverage or food intake prior to testing. None of the subjects were involved in any fatiguing training activities for at least two days before testing. None of the subjects reported any acute injuries during testing.

Anthropometric Measures

Testers used a stadiometer to measure the distance from the subject’s bottom of the foot to the top tip of the head to record height. Weight was measured using a regular weighing scale.

¾ sprint test. Running speed is important for basketball; it was measured using a ¾ sprint test, which is also part of the NBA combined pre-draft test. The tester placed two cones at the baseline and opposite free-throw lane. Athletes were instructed to run ¾ of the court (22.86 m) at full speed. Two trials were allowed, and the best result was recorded at the nearest 0.01 sec.

Box Agility Test

The box agility test is a special test for basketball players and is one of the basic tests in the NBA Combine pre-draft test. Four cones were placed in a pro-size foul lane on a basketball court. Athletes start to run forward towards the baseline, then change movement to side shuffle at the cone. The shuffle to the next cone then changes to the back pedal up the lane to the next cone on the foul lane. The side shuffle is then changed again to the starting point. After touching the starting cone with the hand, the reverse direction side shuffled to the opposite cone on the foul line. The same pattern is used to return the starting cone. Two trials were performed, and the best time was recorded to the nearest 0.01 second. During the test, the subjects were instructed not to move or knock down any cones. Cutting corners and sprinting sideways instead of shuffling are not allowed.

1 RM Bench Press

The upper body strength was tested using a 1 RM bench press (kg). Athletes were allowed to do warm-up sets with light weights for 5–10 repetitions and heavy weights for 2–3 repetitions. Athletes started with 85% of their recent maximum load. They could adjust the load based on their choice. Any inability to complete the test and improper technique were considered failures. Subject relative upper body strength was calculated by dividing 1 RM bench press (kg) by body mass (kg), multiplied by 100, and recorded as a percentage.

1 RM Squat

Lower body strength was tested using a 1 RM squat (kg). Athletes are allowed to do a warm-up set with moderate weight of their choice for 5–10 repetitions. For safety concerns, two trained testers were spotted on each side of the bar, and one trainer was spotted behind the subject during the test. Athletes started standing with their feet shoulder-width apart. The athletes started by performing a back squat with 85% of their recent maximum load. Subjects were required to squat below the level of the femur and demonstrate a proper technique. They could adjust the load based on their choice. Any inability to complete the test and improper technique were considered failures. Subject relative lower body strength was calculated as 1 RM back squat (kg) divided by body mass (kg), multiplied by 100, and recorded as a percentage.

65 kg Bench Press

We used a 65 kg bench press for maximum repetitions to test the subject’s muscular endurance. Athletes were allowed to do a warm-up set with moderate weight by their choice. For safety concerns, one tester stood behind the bar, providing the necessary spotting. Athletes started in the supine position on the bench. Athletes performed the maximum number of full repetitions, and results were recorded. The movement of the bar should be at a controlled pace, and the bar should be in line with the nipples.

17- line Shuttle Run

Lower body muscular endurance was tested through the timed 17-line shuttle run.

Statistical Analysis

One-way ANOVA tests were used to analyze the effect of training on the improvement of strength variables. The level of significance was set at p = 0.05.

Results

The experimental group was compared with the baseline tests and mid-tests, and within three months, all variables demonstrated significance (Table I). The experimental group results compared with the final test at the end of three months showed significance for most variables, with the exception of the box agility test.

Table I. Results For Experimental Group

Tests	Baseline	Mid-test	p	Final test	p
¾ Sprint (sec)	3.6 ± 0.13	3.52 ± 0.14	0.002	3.39 ± 0.19	<0.001
Box agility (sec)	12.35 ± 0.58	12.03 ± 0.50	0.016	10.69 ± 3.13	0.066
1RM bench press (kg)	75.71 ± 17.30	88.21 ± 14.08	<0.001	104.64 ± 16.34	<0.001
1RM squat (kg)	133.57 ± 21.69	162.14 ± 26.65	<0.001	177.85 ± 23.26	<0.001
65 kg bench press (Rep)	7.5 ± 7.47	11.0 ± 6.71	<0.001	17.42 ± 6.18	<0.001
17-line shuttle run (sec)	63.94 ± 4.57	61.05 ± 2.86	0.005	59.28 ± 2.41	0.003

As shown in Table II, the control group results showed significant changes for most variables besides the 1 RM and 65 kg bench press tests.

Table II. Results For Control Group

Tests	Baseline	Final test	p
¾ Sprint (sec)	3.83 ± 0.40	3.75 ± 0.42	0.015
Box agility (sec)	13.39 ± 1.15	13 ± 0.93	0.003
1RM bench press (kg)	56.76 ± 13.8	62.35 ± 15.52	0.001
1RM squat (kg)	52.35 ± 64.76	102.35 ± 92.63	0.104
65 kg bench press (Rep)	0.58 ± 1.41	1.05 ± 1.85	0.104
17-line shuttle run (sec)	66.59 ± 7.14	65.61 ± 6.96	0.001

According to the data presented in Table III, the experimental group showed greater improvements than the control group. As shown in Table I, the 65 kg bench press for the maximal repetition test in the experimental group increased by 132.26% compared with the baseline test. In the 1 RM bench press test, the experimental group’s final test results increased by 38.21% compared with the baseline test. In the 1 RM squat test, the final test results increased by 33.15%; in the box agility test, the final test results improved by 13.44%; and in the ¾ sprint test, the final test results improved by 5.86% compared with the baseline test.

Table III. Experimental Group Compared with the Control Group

Tests	Experimental group	Control group	p
¾ sprint (sec)	3.39 ± 0.19	3.75 ± 0.42	0.004
Box agility (sec)	10.69 ± 3.13	13 ± 0.93	0.007
1RM bench press (kg)	104.64 ± 16.34	62.35 ± 15.52	<0.001
1RM squat (kg)	177.85 ± 23.26	102.35 ± 92.63	0.004
65 kg bench press (reps)	17.42 ± 6.18	1.05 ± 1.85	<0.001
17-line shuttle run (sec)	59.28 ± 2.41	65.61 ± 6.96	0.002

Table IV. Summarized Three-month Training Program

Weeks 1–6: Basic strength/ Hypertrophy/ Endurance		Day one (Basic strength)	Day two (Endurance)	Day Three (Hypertrophy)
	Rep range	1–5	10+	6–8
	Exercises	Sprints (10–100 m)	Tempo runs (200–1200m)	Agility (Pattern drills)
		Bench press (x1–x5)	Bench press (x10–x15)	DB bench press (x6–x8)
		Pull ups (x3-xMax)	Lat pulldown/Row (x10–x15)	DB rows (x6–x8)
		Back squat (x1–x5)	Deadlift/RDL (x10–x15)	Single Leg RDL/Squat (x6–x8)
		Box jump (x1–x5)	Hip flexion (x10–x15)	Lunges (x6–x8)
	Intensity	Max effort 75%–100%	<70% Max effort	50%–85% Effort
Week 6: Retest
Weeks 7-12 Max Strength/Speed/ Power		Day one (Max strength)	Day two (Speed)	Day three (Power)
	Rep range	1–3	3–5	1–3
	Exercise	Sprints (100–10 m)	Tempo runs (1200–200 m)	Agility (Pattern drills)
		Bench press (x1–x3)	Speed bench Press (x3–x5)	Clap push ups (x1–x3)
		Pull ups (x5–xMax)	Lat pulldown/Row (x5)	Clap pull ups (x1–x3)
		Back squat (x1–x3)	Speed deadlift/RDL (x3–x5)	Squat jumps (Weighted) (x1–x3)
		Box jump (x1–x5)	Hip flexion (x5)	Single leg bounds (x3)
	Intensity	Max effort 80%–105%	<70% Max effort	90% Effort
Week 12: Post-test

Discussion

The efficacy of chiropractic care has been a controversial topic over the years, with many studies suggesting that its benefits are merely the result of the placebo effect. This skepticism stems from early research and anecdotal evidence that failed to conclusively demonstrate the effectiveness of chiropractic treatments beyond patient expectations and placebo response. However, recent research has shown physiological benefits derived from chiropractic treatments that surpass placebo effects. For example, studies have found that chiropractic care can reduce muscle inhibition, with cervical spine manipulation resulting in a statistically significant immediate decrease in muscle inhibition in both bicep muscles (Gay & Bishop, 2014; Suter & McMorland, 2002). According to our results, the performance of both groups improved with the intervention of chiropractic manipulation.

The participation of adolescent athletes in strength and conditioning programs has also been a topic of debate in recent years. Prestigious organizations and strength and conditioning associations have published standards and guidance regarding training for young athletes (American Academy of Pediatrics Council on Sports Medicine and Fitness, 2008; American College of Sports Medicine, 1998; Faigenbaum & Micheli, 2017). Research on the strength conditioning levels of athletes of various ages suggests that teen athletes should be prescribed appropriate training programs closely monitored by trained professionals due to physiological age discrepancies with biological age (Brenner & Council on Sports Medicine and Fitness, 2016; Brownet al., 2017; Lloydet al., 2015). Previous studies have suggested that adolescent players should begin receiving sports-specific training during middle adolescence and specialize in team sports, tennis, and golf, whereas late adolescence is recommended for track and field and endurance sports (Fabricantet al., 2016; Myeret al., 2016; Zhanget al., 2024).

Despite this, no research has specifically studied the combined effects of chiropractic manipulation and strength conditioning on adolescent athletes to determine if this combination could provide positive benefits for their development. Our study results indicated that athletes who were professionally trained for three months combined with chiropractic care could have a significant improvement in their general strength, muscular endurance, speed, and agility compared with a control group that only showed a minor improvement in each category. This indicates that a three-month strength training program combined with chiropractic care could greatly benefit adolescent athletes’ physical performance.

Based on these results, strength, speed, endurance, and agility improved significantly due to consistent training within the three-month program. Additionally, chiropractic manipulation helped stimulate the neuromuscular system. However, the results for the control group also improved, suggesting that chiropractic manipulation may indirectly assist athletes in enhancing their performance. These findings align with other chiropractic literature, which emphasizes the improvement of neurological integrity as a key factor in the beneficial effects of chiropractic manipulation (Smith & Cox, 2000).

Prior studies have revealed that increased strength from training may enhance physical abilities such as long jump, vertical jump, 30-m dash, squat jump, and agility runs (Christouet al., 2006; Falk & Mor, 1996; Lillegardet al., 1997). Our findings are consistent with those of previous research. However, this study has some limitations that require further investigation. One major question is whether the variables studied contribute to the overall basketball performance. Although our results suggest that a defined training program can affect these variables, the study did not measure on-court basketball performance, making it unclear whether improvements in these variables translate to better game performance.

Much of the concern regarding the incidence of injuries associated with early strength and conditioning in adolescent athletes comes from parents’ and coaches’ concerns. Therefore, it is important to evaluate general fitness and develop specific training programs to decrease injury rates. According to the guidelines of the American Academy of Pediatrics, workouts should be at least 20 to 30 minutes, with an adequate frequency of 2–3 times per week (American Academy of Pediatrics Council on Sports Medicine and Fitness, 2008; Balyi, 2001). The frequency of training more than four times per week and participating in over 16 hours per week of organized sports activities could increase the potential injury risk for adolescent athletes (Myeret al., 2015; Postet al., 2017). The strength and conditioning program designed for adolescent players in this research utilized a frequency of three times per week, and the entire duration of the training camp lasted for a 3-month period. Additionally, weekly chiropractic care addresses subluxation issues related to sports activities, may potentially enhance the effectiveness of training programs and possibly reduce the risk of injury. This was confirmed by adequate strength gains, speed, endurance, and agility. However, this study does not conclude the incidence of injury rate within it, and further research should be conducted to clarify the relationship between strength and conditioning training combined with chiropractic care associated with injury rate in adolescent athletes.

Practical Applications

This should be considered in conjunction with the training of adolescent athletes and their sports-specific training. It is also important to evaluate whether chiropractic care should be integrated into sports performance programs.

Conclusion

A specific, professionally conducted strength and conditioning program, combined with chiropractic care, can significantly improve the physical performance of adolescent athletes. Strength, endurance, speed, and agility training are recommended for adolescents to enhance their athletic development.